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MECHANICAL ENGINEERINGHigher

Third edition – published December 1999

Mechanical Engineering: Higher Course 1

NOTE OF CHANGES TO ARRANGEMENTSTHIRD EDITION PUBLISHED ON CD-ROM DECEMBER 1999

COURSE TITLE: Mechanical Engineering (Higher)

COURSE NUMBER: C031 12

National Course Specification:

Course Details: Core skills statements expanded

National Unit Specification:

All Units: Core skills statements expanded

Administrative Information

Publication date: December 1999

Source: Scottish Qualifications Authority

Version: 03

© Scottish Qualifications Authority 1999

This publication may be reproduced in whole or in part for educational purposes provided that no profit is derived fromreproduction and that, if reproduced in part, the source is acknowledged.

Additional copies of this specification (including unit specifications) can be purchased from the Scottish QualificationsAuthority for £7.50. Note: Unit specifications can be purchased individually for £2.50 (minimum order £5).

2

National Course Specification

MECHANICAL ENGINEERING (HIGHER)

COURSE NUMBER C031 12

COURSE STRUCTURE

This course comprises three mandatory units, as follows:

D160 12 Dynamics (H) 1 credit (40 hours)D161 12 Strength of Materials (H) 1 credit (40 hours)D162 12 Thermofluids 1 credit (40 hours)

In common with all courses, this course includes 40 hours over and above the 120 hours for thecomponent units. This is for induction, extending the range of learning and teaching approaches,support, consolidation, integration of learning and preparation for external assessment. This time isan important element of the course and advice on its use is included in the course details.

RECOMMENDED ENTRY

While entry is at the discretion of the centre, candidates would normally be expected to have attainedone of the following:

• Intermediate 2 Structures, together with Mathematics and Physics at Intermediate 1 or above• Standard Grade Mathematics with either Standard Grade Technological Studies or Physics at

grade 2 or above• equivalent or appropriate National units or courses• Intermediate 2 Scottish Group Award in a related area.


National Course Specification (cont)

COURSE Mechanical Engineering (Higher)

CORE SKILLS

This course gives automatic certification of the following:

Complete core skills for the course Numeracy Int 2

Additional core skills components for the course Critical Thinking HUsing Number H

Additional information about core skills is published in Automatic Certification of Core Skills inNational Qualifications (SQA, 1999).


National Course Specification: course details


RATIONALE

The products of mechanical engineering innovation surround us. They contribute in some form tovirtually every area of human endeavour and without them, society as we know it could not function.The range of applications of mechanical engineering is enormous, varying in scale and precision fromthe micro-miniature to immense structures in the form of bridges, supertankers, oil platforms andtower blocks. Mechanical engineering’s contribution to economic growth and the development ofsociety has been and still is immense. Where would society be without electricity generating stations,oil refineries, modern transportation systems? Modern motor vehicles, high-speed trains and fast,quiet, reliable passenger aircraft are obvious examples of the way in which mechanical engineeringhas played a major part in sophisticated modern products which have become essential to oureveryday lives. Perhaps less obvious but equally important to individuals and to society is the rolewhich mechanical engineering has played in the development of modern medical equipment, from all-body scanners to artificial heart valves. Many of the complex peripheral devices which are anessential feature of modern information technology systems rely heavily on advanced mechanicalengineering designs.

This course provides the opportunity for individuals to develop the skills and knowledge to help themunderstand mechanical engineering concepts which underpin so many exciting developments.

The course is intended to provide the candidate with the knowledge and understanding of a broadsection of mechanical engineering principles and applications. It will establish importantfundamentals for those interested in a career in a variety of mechanical engineering disciplines. Thebreadth of study makes it a worthwhile contributor to general education and the advancement oftechnological capability.

The aim of the course is to bring a level of knowledge and understanding to candidates who wish toseek employment as technician engineers or entry to study at a higher level. Successful completion ofthis course will indicate that a candidate has mastered the fundamental concepts required forquantitative analysis in major areas of technological capability.

The components of the course when successfully completed will allow candidates to apply theprinciples and laws which relate to:

• changes in linear and angular motion• effects of static loads causing bending and twisting, including designing for these conditions• gas laws and the use of properties of vapours to analyse and solve problems associated with

simple steady flow energy applications

The knowledge, understanding, skills, attitudes and confidence developed will promote ways ofthinking which help to draw together aesthetic, economic and environmental factors with ergonomic,technical and scientific principles.

This knowledge will also improve the candidate’s ability to relate technological capability to everydaysituations. The course will also allow practice of a number of core skills (Critical Thinking and UsingNumber) within a technological context.


National Course Specification: course details (cont)


COURSE CONTENT

All of the course content will be subject to sampling in the external assessment.

The separate units reflect the three main strands of mechanical engineering theory and principles.Once competence has been reached in using these techniques in an individual way, the full process ofmechanical engineering can begin where the candidate learns to analyse a situation and develop anengineering solution.

A full investigation of the system and its parameters leads to the ordering of relevant information toallow informed decisions to be taken on the size of the system, its power requirements, materialselection, safety considerations, quality and performance requirements. Candidates successfullycompleting the course, as distinct from achieving the individual units, should benefit from beingskilled in a holistic approach to the analysis of a situation. This will require a mechanical engineeringsolution to be developed from various possibilities which have been considered and compared. Theoptimum solution would then be progressed to final mechanisms, components, materials anddimensions.

This approach will require candidates to:

• integrate aspects of the course content• apply knowledge and skills in a wide range of contexts• demonstrate a familiarity of course content beyond that indicated in the unit specifications• apply knowledge and skills in a more complex way

Some examples of techniques used to help candidates achieve these additional demands, follow.

The force and turning effects caused by fluids on submerged surfaces such as valves or gates arestudied in the Thermofluids unit. Such forces are often resisted or overcome by mechanical devicessuch as levers or torsionally loaded members which are studied in the Strength of Materials unit. Thecourse ensures that integration of the content of units takes place and confirms the interrelationship ofengineering solutions.

The range of contexts can be widened in a large number of ways. For example, the analysis oftemperature effects endured by components in thermodynamic devices may well lead to the study ofresidual stress situations. This extends the context in which loading is usually considered to be causedby force or weight application.

Some of the additional 40 hours could be used to analyse a range of carefully chosen engineeringapplications to widen the range of the candidate’s experience.

Application of knowledge and skill in more complex situations can be approached in several ways.Analysing a range of applications widens experience, and some scenarios may include considerationof a greater number of variables or the use of specialist software to deduce parameters.

The syllabus to be covered in relation to the component units can be attempted either concurrently orsequentially. The added value of the course award would be achieved by applying the principles andtechniques mastered in the separate units to situations where some dynamic, strength of material and




thermofluid factors are present. Decisions reached from separate analyses require to be synthesised inorder to achieve a solution allowing for all relevant factors. The techniques required to achieve thisholistic approach can be developed as part of the additional 40 hours making up the course.

SUMMARY OF COURSE CONTENT

Dynamics (H)

Solution of problems related to systems which have elements moving linearly or angularly in order tocalculate force, torque, work and power quantities associated with systems of this type. Solution ofproblems using Newton’s Second Law as applied to linear and angular motion. Condition ofcentripetal acceleration, including the calculation of centripetal force.

Candidates should learn that prime movers such as turbines use working fluids such as gas or vapourto cause the dynamic effects being analysed. The size and shape of structural members andcomponents such as shafts are deduced using the techniques developed in the Strength of Materialsunit.




CONTENT STATEMENTSDynamics (H)

The content statements given in the left-hand column of the table below describe in detail what thecandidate should be able to do in demonstrating knowledge and understanding associated withdynamics.

The right-hand column gives suggested contexts, applications, illustrations and activities associatedwith the content statement.

KNOWLEDGE AND UNDERSTANDING CONTEXTS, APPLICATIONS,ILLUSTRATIONS AND ACTIVITIES

Linear and angular motion

1 Velocity vs. time diagrams, leading to the useof equations of motion.

2 Apply Newton’s second law.

3 Combined problems.

Work and power transfer

1 Definitions of quantities.

2 Calculate work and power quantities.

Energy balances

1 Define different forms of energy.

2 The law of conservation of energy.

Centripetal acceleration

1 Describe the parameters of circular motion.

2 Solving problems.

3 Centripetal force experiment.

Application to both linear and angular systems.To calculate both displacement and accelerationquantities.

The relationship between the linear and angularparameters.

To determine the relationship between force,mass and acceleration/torque, inertia and angularacceleration.

Solution of dynamic problems involving onelinear and one angular component.

Quantifying units as joules, joules per second,watts.

Pick up examples from the force/torquecalculations and extend them to work and power.

Kinetic and potential.

Energy balances can be used as an alternativemethod of solving the problems above.

Centripetal acceleration and force.

Relate the theoretical analysis to practicalsituations such as vehicles, centrifugal clutch andsimple balancing requirements.

A simple experiment to verify the theory bybalancing linear and angular forces and thencomparing the theoretical and practical results.





Strength of Materials (H)

Design requirements for statically loaded components and structures subjected to temperature change,bending and twisting will be arrived at by analysis of the loading conditions. Further factors relatingto determination of appropriate design require maximum stress to be calculated, and the necessaryshape and size of support members to be deduced so that the components or structure function safely.Loaded structures and devices under combined loading effects, such as direct and bending stress, willalso be analysed.

Reference should be made during presentation to the dynamic effects on moving systems causingextra forces to be experienced by the structural components, and also to the fact that if the system ispart of a thermodynamic device, it will be influenced by effects such as considerable temperaturechange.




CONTENT STATEMENTS

Strength of Materials (H)

The content statements given in the left-hand column of the table below describe in detail what thecandidate should be able to do in demonstrating knowledge and understanding associated withstrength of materials.



Simply supported beams and cantilevers

1 Calculation of reactions.

2 Construction of bending moment, shear forceand thrust diagrams.

Simple bending theory

1 Familiarisation with the simple bendingequation.

2 Solve problems associated with the simplebending theory.

The torsion equation

1 Familiarisation with the simple torsionequation.

2 Solve problems associated with the simpletorsion theory.

Design components

1 Extracting material properties fromdatabases.

2 Deduce design stresses.

3 Analyse loading conditions.

By taking moments or using force balances.

Diagrams are to include point loads, uniformlydistributed loads, turning points, zero shear,points of contraflecture.

All parameters are to be identified by words andsymbols, correct units for all values. Calculationof the second moment of area/section modulusfor simple cross-sections.

These should include the determination of thestress distribution across the cross-section of thebeam.

All parameters are to be identified by words andsymbols, correct units for all values. Calculationof the polar second moment of area for simplecross-sections restricted to solid and hollowcircular shafts.

These should include the determination of thestress distribution across the cross-section of theshaft.

Minimum of six materials to be considered. Theproperties should include elastic limit or proofstress, ultimate strength, moduli of elasticity andrigidity.

Deductions should take into account loadingconsiderations, environmental effects, cycliceffects and shearing situations.

To include any two combined effects.





Thermofluids (H)

The movement of working fluids and corresponding changes in fluid properties will be analysed forflow through thermodynamic equipment such as boilers, heat exchangers, turbines, compressors andthe connecting circuits. This requires candidates to calculate energy changes in the fluid, and transferof work and heat quantities to and from the system. The behaviour of fluids at rest is investigated topermit candidates to analyse applications such as manometers and force on submerged areas, andallow problem-solving in these contexts.

Reference should be made in the unit to the fact that the purpose of many thermodynamic devices isto transfer heat and work from the system. As a consequence of these processes, dynamic effectsoccur to some of the structural members. This causes a clear path of interactive developmentsbetween the behaviour of the working fluid, the dynamic effects on the system components, and thenecessary size and shape for the system to perform its function effectively and safely.

During the additional 40 hours study time associated with the course, several examples of systemsinvolving dynamic effects caused by thermofluids should be observed and analysed. This could bedone progressively, leading to further quantitative analysis of these and other systems, involvingsubject matter from any two of the three units which make up the course.

The strength of the course award as opposed to achievement of the individual units is in the abilityfostered in the candidate to look at a system as a whole, and analyse the thermofluid, dynamic andstructural requirements in order to decide material and dimensional requirements. The candidate willdevelop powers of logical analysis, the ability to decide which parameters in a complex situation areimportant, and how these effects impinge on other related factors, and so come to a preferred solution.In order not to overburden the candidate with complexity, particular applications should only sampleacross the outcomes of any two units.

CONTENT STATEMENTS

Thermofluids (H)

The content statements given in the left-hand column of the following table describe in detail what thecandidate should be able to do in demonstrating knowledge and understanding associated withthermofluids.





CONTENT STATEMENTS

Thermofluids (H)


The Gas Laws

1 Describe the individual laws.

2 Use the combined gas law.

3 Solve problems involving perfect gases.

4 Solve practical problems.

5 Practical work.

Properties of vapours

1 Extract data for thermodynamic propertytables.

2 Interpolation of values.

3 Solve problems using data from tables.

Steady flow energy equation (SFEE)

1 Input/Output process approach is used todescribe common thermodynamic process.

2 Solve problems using SFEE.

3 Applications of the SFEE to analyse practicalsituations.

Boyle’s law or Charles’s law could be used asexamples.

= Constant, PV = mRT

To include the calculation of properties.

Internal combustion engines, gas turbines andnozzles.

Where possible, practical demonstrations shouldbe used.

Fluids should be limited to water and refrigerants.

Properties are to include saturation temperatureand pressure, internal energy, enthalpy specificvolume.

In undercooled liquid, saturated liquid, wetvapour, saturated vapour and super heater vapourconditions.

Restricted to enthalpy, internal energy andspecific volume.

Problems should include a change of phase.

Calculation of dryness fraction and degree ofsuperheat.

Problems should be broken down to simplifiedInput/Output diagrams: for example boiler, heatexchanger or turbine.

Starting with problems that eliminate many of theenergy terms and increasing the difficulty to amaximum of three subsystems.

Analyse a practical situation using SFEE.

PVT




CONTENT STATEMENTS

Thermofluids (H) (cont)


Flow through pipes

1 Derive Bernoulli’s equation from the SFEE.

2 Mass continuity.

3 Solve problems using Bernoulli’s equation.

Static fluid behaviour

1 Manometry.

2 Convert height differences to flow.

3 Relate pressure on submerged plates todepths.

Eliminate irrelevant terms and replace specificvolume with density.

To include inclined pipe, convergent anddivergent pipes, venturimeter, restricted toincompressible flow.

Piezometer tube, U-tube manometers only.

Calculation of thrust on submerged areas andposition of centre of pressure on submerged andpartially submerged plates. Restricted to pressureon one side only, and rectangular and roundplates only.




ASSESSMENT

To gain the award of the course, the candidate must pass all the unit assessments as well as theexternal assessment. External assessment will provide the basis for grading attainment in the courseaward.

When the units are taken as component parts of a course, candidates will have the opportunity toachieve a level beyond that required to attain each of the unit outcomes. This attainment may, whereappropriate, be recorded and used to contribute towards course estimates, and to provide evidence forappeals. Additional details are provided, where appropriate, with the exemplar assessment materials.Further information on the key principles of assessment is provided in the paper Assessment (HSDU,1996) and in Managing Assessment (HSDU, 1998).

DETAILS OF THE INSTRUMENTS FOR EXTERNAL ASSESSMENT

The external assessment will comprise a written examination paper. The time allocation for thequestion paper will be 3 hours. The paper will be worth 100 marks and will be in three parts asfollows:

Section A – 50 marks

Ten short answer questions will be set. The questions will sample widely across the content of thecourse. They will assess knowledge and understanding across the component units of the course, inextended and less familiar contexts. Candidates should attempt all questions from this section.

Section B – 30 marks

Three extended answer questions will be set. The questions will assess the candidate’s ability toanalyse a range of structured problems. Candidates should attempt two questions from this section.

Section C – 20 marks

Two extended answer questions will be set. The questions will assess the candidate’s ability to tacklemore complex problems and to integrate knowledge from different subject areas in the course. Thecandidate should attempt one question from this section.

The candidate who successfully completes the course assessment should:

• demonstrate the ability to integrate knowledge, understanding, decision-making and numericalskills acquired in component units and practised in an integrated context

• retain knowledge and skills levels over the whole length of the course• apply knowledge and skills in less familiar contexts• apply knowledge and skills in more complex contexts• select necessary data as appropriate from information provided




GRADE DESCRIPTIONS

The descriptions below are of expected performances at grade C and at grade A. they are intended toassist candidates, teachers, lecturers and users of the certificate and to help establish standards whenquestion papers are being set. The grade of the award will be based on the total score obtained in theexamination.

For performance at grade C, candidates should be able to:

• Use consistently the knowledge, understanding and skills in the component units of the course.For example in Outcome 4 of the Dynamics unit, the experimental report on centripetal motionwould contain a tabular comparison between the actual and theoretical centripetal force at a rangeof speeds, with the conclusion indicating a broad general correlation with a limited analysis of thevariables.

• Apply the knowledge and understanding gained in the component units correctly to the solution ofstructured problems in a limited range of contexts. For example in Outcome 2 of the Strength ofMaterials unit, when using the Simple Bending Equation the correctly related parts of theequation are selected and the values are taken directly from the problem, entered in the equationin the appropriate units and the problem solved.

• Demonstrate ability to integrate the knowledge, understanding and skills acquired throughout thecomponent units. For example in Outcome 5 of the Thermofluids unit, when solving problemsconcerning submerged areas, calculated requirements would be restricted to the fluid force andposition on the submerged area.

For performance at grade A, candidates should be able to:

• Use the knowledge, understanding and skills acquired in the component units of the courseconsistently and effectively. For example, in Outcome 4 of the Dynamics unit, the experimentalreport on centripetal motion would contain a tabular and graphical comparison of the actual andtheoretical centripetal force over a relevant range of speeds. The conclusion should indicatequantified sources of errors, possible experimental improvements and a clear consideration of thedegree of success achieved during the performance of the experiment.

• Apply the knowledge and understanding gained in the component units correctly to the solution ofunstructured extended problems in more complex contexts. For example, in Outcome 2 of theStrength of Materials unit, when using the Simple Bending Equation the correctly related parts ofthe equation are selected and the values of up to three of the variables calculated or deduced fromthe information given in the problem, entered in the equation in the appropriate units and theproblem solved.

• Demonstrate considerable ability to integrate the knowledge, understanding and skills acquiredthrough the component units. For example, in Outcome 5 of the Thermofluids unit, when solvingproblems concerning submerged areas, calculated requirements would be extended beyond thefluid force and its position on the submerged area to include the application of the principles fromthe Strength of Materials unit i.e. to calculate other parameters such as a hinge reaction on thesubmerged area and then appropriate dimensions for the hinge pin.




APPROACHES TO LEARNING AND TEACHING

Although the course is essentially theoretical in nature, an understanding of practical procedures andof the engineering components and structures which make up the many important systems essential toour civilised way of life, should be studied at every opportunity. Planned visits, possibly to a powerstation, manufacturing plant or a processing plant such as an oil refinery, video presentations andmanufacturers’ educational materials all have important contributions to make. Case studies of howengineering problems have been solved in the recent past would be a useful resource to focuscandidate interest and promote understanding of real world problems and solutions. The additional 40hours could be used to investigate a range of simplified real engineering systems which depend onaspects of thermofluids, dynamics and strength of materials for their design or operation.Applications should sample across units and require a balance of learning and experience.

Numerical analysis should be developed using a series of case studies or coursework of increasingcomplexity to enable the candidate to draw on the skills acquired in the separate outcomes and units.Group tutorials, practical demonstrations and computer software should all be used where appropriate.

In advance of the external assessment, candidates should be given some experience of the type ofchallenge involved so that they are not surprised by the format and duration.

SPECIAL NEEDS

This course specification is intended to ensure that there are no artificial barriers to learning orassessment. Special needs of individual candidates should be taken into account when planninglearning experiences, selecting assessment instruments or considering alternative outcomes for units.For information on these, please refer to the SQA document Guidance on Special Assessment andCertification Arrangements for Candidates with Special Needs/Candidates whose First Language isnot English (SQA, 1998).

SUBJECT GUIDES

A Subject Guide to accompany the Arrangements documents has been produced by the Higher StillDevelopment Unit (HSDU) in partnership with the Scottish Further Education Unit (SFEU) andScottish Consultative Council on the Curriculum (SCCC). The Guide provides further advice andinformation about:

• support materials for each course• learning and teaching approaches in addition to the information provided in the Arrangements

document• assessment• ensuring appropriate access for candidates with special educational needs.

The Subject Guide is intended to support the information contained in the Arrangements document.The SQA Arrangements documents contain the standards against which candidates are assessed.


Superclass: RC



Version: 03



Additional copies of this unit specification can be purchased from the Scottish Qualifications Authority. The cost for eachunit specification is £2.50 (minimum order £5).

16

National Unit Specification: general information

UNIT Dynamics (Higher)

NUMBER D160 12


SUMMARY

The unit focuses on applying engineering principles and laws to the analysis of situations involvingchanges in linear and angular motion. This unit would be useful to candidates who require to developcompetence in the application of engineering science principles to dynamic systems. Much of thecontent is directly useful over a wide range of applications.

OUTCOMES

1 Solve problems using Newton’s Second Law applied to linear and angular motion.2 Apply work and power transfer theory to linear and angular systems.3 Analyse the kinetics of motion using an energy balance approach.4 Analyse uniform circular motion force systems.

RECOMMENDED ENTRY



grade 2 or above• equivalent or appropriate National units• Intermediate 2 Scottish Group Award in a related area.

Mechanical Engineering: Unit Specification – Dynamics (H) 17

National Unit Specification: general information (cont)


CREDIT VALUE

1 credit at Higher.

CORE SKILLS

This unit gives automatic certification of the following:

Complete core skills for the unit None

Core skills components for the unit Critical Thinking HUsing Number H



National Unit Specification: statement of standards


Acceptable performance in this unit will be the satisfactory achievement of the standards set out inthis part of the unit specification. All sections of the statement of standards are mandatory and cannotbe altered without reference to the Scottish Qualifications Authority.

OUTCOME 1

Solve problems using Newton’s Second Law applied to linear and angular motion.

Performance criteria

(a) The elements of motion are accurately defined in accordance with established theory.(b) The interrelationships between the elements of motion are analysed in accordance with

established theory.(c) Problems relating to systems affected by uniform acceleration are solved correctly.

Note on range for the outcome

Motion: linear, angular, combined (limited to one linear and one angular influence).Elements: displacement, velocity, acceleration, time, accelerating force, accelerating torque.

Evidence requirements

Written and/or oral evidence that the candidate can solve problems using Newton’s Second Law asdescribed in the PCs for one simple system with one angular and one linear component of motion.

OUTCOME 2

Apply work and power transfer theory to linear and angular systems.


(a) Work and power quantities are defined correctly in accordance with established theory.(b) Work and power calculations are performed correctly.(c) Problems related to systems affected by constant and variable applied forces are solved

accurately.


Systems: linear, angular, combined (limited to one linear and one angular influence).


Written and/or oral evidence that the candidate can apply work and power transfer theory to a simplesystem containing both linear and angular motion as described in PCs (a) to (c).


National Unit Specification: statement of standards (cont)


OUTCOME 3

Analyse the kinetics of motion using an energy balance approach.


(a) The influences affecting kinetic energy are defined correctly in accordance with establishedtheory.

(b) Energy balance principles are applied to motion systems correctly.(c) Problems relating to systems affected by uniform acceleration are solved accurately.


Systems: linear, angular, combined (limited to one linear and one angular influence).Forms of energy: potential, kinetic.


Written and/or oral evidence that the candidate can apply energy balance principles as described inPCs (a) to (c) across all classes in the range.

OUTCOME 4

Analyse uniform circular motion force systems.


(a) Centripetal acceleration is defined correctly in terms of a requirement for circular motion inaccordance with established theory.

(b) An experiment to verify the theory of centripetal acceleration is performed satisfactorily.(c) The effect of centripetal acceleration on mechanisms is qualitatively described correctly.


Mechanisms: vehicle movement, centrifugal clutch, simple balancing requirements.


Written and/or oral evidence that the candidate can describe uniform circular motion force systems asdescribed in PCs (a) and (c) across all classes of the range, along with written evidence that thecandidate has successfully completed the experiment as described in PC (b).


National Unit Specification: support notes


This part of the unit specification is offered as guidance. The support notes are not mandatory.

It is recommended that you refer to the SQA Arrangements document for Higher MechanicalEngineering before delivering this unit.

While the exact time allocated to this unit is at the discretion of the centre, the notional design lengthis 40 hours.

On successful completion of the unit a candidate will be able to solve problems related to systemswhich have elements moving linearly or angularly. He or she will also be able to calculate force,torque, work and power quantities associated with systems of this type and to analyse systemsaffected by centripetal acceleration and its related factors.

The content of this unit would be directly beneficial for those intending to proceed to a degree orHNC/D course in a range of engineering and related disciplines.

GUIDANCE ON CONTENT AND CONTEXT FOR THIS UNIT

The application of principles should be supplemented by practical demonstration. Computer softwareshould be made available where appropriate.

A graded tutorial system reflecting a wide range of vocational interests would be appropriate for alloutcomes. An integrated presentation is possible and this would be reflected by integrated assessmentinstruments.

A simple presentation, demonstration and discussion of motion using either a velocity/time diagramapproach or the equations of motion can be combined with application of Newton’s Second Law toallow the candidate to become familiar with the terminology and overall parameters involved.Various linear and angular systems can then be analysed and calculations attempted relatingforce/torque to acceleration.

Once single element systems have been mastered, combined linear-angular systems can be introducedand supported by tutorial examples.

Work and power calculations can now be introduced and included in previously completed analysisand calculations.

Some revision of energy forms and calculations, followed by application of the principle of energybalance, can then be applied to the same systems used in Outcomes 1 and 2, as an alternative methodof solution perhaps initially limited to linear systems. Angular systems can then be approached and amore comprehensive understanding of polar movement of inertia attempted, followed by analysis andapplication to combined systems.

Either experimental or theoretical approaches to the dynamics of a single mass rotating in a horizontalcircular path can be used to deduce the centripetal acceleration/force necessary to achieve this type ofmotion. Analysis and calculations on a range of applications can now be completed individually andin small groups. The experimental nature of this type of analysis may be used as a vehicle tostimulate candidate interest in investigation, ordering and analysing results and reaching logicalconclusions. This approach would be good preparation for future study.


National Unit Specification: support notes (cont)


GUIDANCE ON LEARNING AND TEACHING APPROACHES FOR THIS UNIT

Although the unit is essentially theoretical in nature, an understanding of practical procedures and ofthe engineering components and structures which make up the many important systems essential toour civilised way of life should be studied at every opportunity.

Planned visits, possibly to a power station, manufacturing plant or a processing plant such as an oilrefinery, video presentations and manufacturers’ educational materials all have importantcontributions to make. Case studies of how engineering problems have been resolved in the recentpast would be a useful resource to focus candidate’s interest and promote understanding of real worldproblems and solutions.


The content statements given in the left-hand column of the following table describe in detail what thecandidate should be able to do in demonstrating knowledge and understanding associated withdynamics.






Linear and angular motion

1 Velocity vs. time diagrams, leading to the useof equations of motion.

2 Apply Newton’s second law.

3 Combined problems.

Work and power transfer

1 Definitions of quantities.

2 Calculate work and power quantities.

Energy balances

1 Define different forms of energy.

2 The law of conservation of energy.

Centripetal acceleration

1 Describe the parameters of circular motion.

2 Solving problems.

3 Centripetal force experiment.

Application to both linear and angular systems.

To calculate both displacement and accelerationquantities.

The relationship between the linear and angularparameters.

To determine the relationship between force,mass and acceleration/torque inertia and angularacceleration.

Solution of dynamic problems involving onelinear and one angular component.

Quantifying units as joules, joules per second,watts.

Pick up examples from the force/torquecalculations and extend them to work and power.

Kinetic and potential.

Energy balances can be used as an alternativemethod of solving the problems above.

Centripetal acceleration and force.

Relate the theoretical analysis to practicalsituations such as vehicles, centrifugal clutch andsimple balancing requirements.

A simple experiment to verify the theory bybalancing linear and angular forces and thencomparing the theoretical and practical results.




GUIDANCE ON APPROACHES TO ASSESSMENT FOR THIS UNIT

Outcome 1

An appropriate instrument of assessment could use prepared data for a system of motion containing oneangular and one linear component of motion. The data could be applied either to different masses or tothe same mass. A structured question would be appropriate, asking the candidate to determine perhapsthree parameters of the system before calculating the required applied force/torque necessary to operatethe system.

Outcomes 2 and 3

Further information could be supplied to the candidate relating to the same system used for Outcome 1.Alternatively, data could be given for another system along with other structured questions requiringdetermination of three parameters. In much the same way an appropriate instrument of assessmentmight elicit an energy balance for a system of two elements. This might involve perhaps four terms inan angular energy balance where one parameter of one term is to be calculated. An appropriateinstrument of assessment would elicit calculation of power requirements at a particular instant and theaverage power requirements where a variable force/torque is applied.

Outcome 4

A standard apparatus can be used for centrifugal force experiments. Alternatively, a simple devicecould be made up where the centripetal force exerted on a rotating mass can be measured. Thecandidate would be presented with this hardware and required to prove that the centripetal force isdirectly proportional to the mass, radius of the circular motion and the square of the angular velocity.The candidate would then be asked to develop the experimental procedure, conduct the experiment,collect tabulate and analyse the results, and reach valid, logical, supportable conclusions. The reportshowing that all these factors had been successfully processed would form an appropriate assessmentinstrument.

Short answer questions, possibly based on diagrams of systems, could be used for PC (c) of Outcome 4.

It would be possible to use the same motion system for Outcomes 1 to 3, with graded questions coveringeach outcome. It would also be possible to use an element of this same system to cover Outcome 4 butthis would be an unnecessary complication. Overall, however, a balance should be sought betweenbreadth of candidate experience and assessment efficiency.

SPECIAL NEEDS

This unit specification is intended to ensure that there are no artificial barriers to learning orassessment. Special needs of individual candidates should be taken into account when planninglearning experiences, selecting assessment instruments or considering alternative outcomes for units.For information on these, please refer to the SQA document Guidance on Special Assessment andCertification Arrangements for Candidates with Special Needs/Candidates whose First Language isnot English (SQA, 1998).


Superclass: RC



Version: 03




24


UNIT Strength of Materials (Higher)

NUMBER D161 12


SUMMARY

This unit focuses on applying engineering principles to the analysis of situations involving static loadson materials. This unit would be useful to candidates who require to apply engineering scienceprinciples to systems under static loading conditions. Much of the content is directly useful over awide range of applications.

OUTCOMES

1 Determine the shear forces and bending moments for simply supported beams and cantilevers.2 Apply the simple bending theory to idealised beams and cantilevers.3 Apply the simple torsion equation to shafts of circular cross-section.4 Design simple components to a given specification.

RECOMMENDED ENTRY




CREDIT VALUE

1 credit at Higher.

Mechanical Engineering: Unit Specification – Strength of Materials (H) 25



CORE SKILLS



Additional core skills components for the unit Critical Thinking Int 2Using Number H






OUTCOME 1

Determine the shear forces and bending moments for simply supported beams and cantilevers.


(a) The extent to which beams and cantilevers are statistically determinate is established correctlyby calculating reactions.

(b) Loading diagrams for beams and cantilevers are drawn correctly.(c) The position of significant values of loading for beams and cantilevers are determined

accurately in terms of their application.


Reactions: pin, frictionless roller, encastered (cantilever only).Loading diagrams: shear force, bending moment, thrust.Significant values: zero shear/maximum bending, contraflexture.


Written and/or oral and graphical evidence which satisfies PCs (a) to (c) and the range as applied toone loaded beam and one loaded cantilever.

OUTCOME 2

Apply the simple bending theory to idealised beams and cantilevers.


(a) Each parameter, term and relationship of the simple bending theory is identified consistentlywith established theory.

(b) Parameters associated with second moment of area are determined from charts and calculationsconsistent with established theory.

(c) Loaded beams and cantilevers are analysed correctly in applying the simple bending theory.(d) Problems related to application of the simple bending theory to beams and cantilevers are

solved correctly.


Parameters: bending moment, second moment of area, bending stress, distance from neutral axis,modulus of elasticity, radius of curvature about the neutral axis.Second moment of area parameters: neutral axis, X and Y axes, distance from neutral axis, secondmoment of area, section modulus.


Written and oral or graphical evidence which satisfies the PCs as applied to one beam and onecantilever problem with the following restrictions:

• point loads and uniformly distributed loads only• two sections selected from the following: simple rectangular; circular; channel and “I” sections only.




OUTCOME 3

Apply the simple torsion equation to shafts of circular cross-section.


(a) Each parameter, term and relationship of the simple torsion equation is identified consistentlywith established theory.

(b) Parameters associated with polar second moment of area are correctly determined from charts andcalculations.

(c) Shafts loaded by torque alone are analysed correctly in applying the simple torsion equation.(d) Problems related to application of the simple torsion equation are solved correctly.


Parameters: torque, polar second moment of area, torsional stress, radius corresponding to torsionalstress, modulus of rigidity, angle of twist, length of shaft.Polar second moment of area parameters: polar axis, radius of gyration, polar second moment of area.Applications: input torque, output torque.Components: circular solid shaft, circular hollow shaft.


Written and/or oral evidence which satisfies the PCs across the range as they apply to one example ofloaded shafts for PCs (a), (c) and (d), which can be either circular solid or hollow, both circular solidand hollow shafts for PC (b): loading by torque alone.

OUTCOME 4

Design simple components to a given specification.


(a) Materials with appropriate engineering properties are selected from an extensive database to meetthe requirements of a given application.

(b) Design stress values are logically deduced in accordance with established procedures.(c) Loading conditions on common components are analysed correctly.(d) Safe component dimensions to support applied load are determined accurately in terms of the

application.


Engineering properties: elastic limit stress, proof stress, moduli of elasticity and rigidity, ultimatestrength.Materials: low carbon steel, cast iron, aluminium, brass, concrete, polymers.Loading conditions: direct and bending combinations, bending and torsional combinations, temperaturestress in complete and partial restraint situations with direct stress combinations.


Written and/or oral evidence which satisfies the PCs and items in the range as they apply to 2 differentloading conditions as applied to 2 separate components. The complete requirement should be workedthrough from material selection, design stress decisions, environmental factors, to the safe loadingcriteria on critical component sections.







This unit would be useful for a candidate who requires to apply engineering science principles tosystems under static loading conditions. Much of the content is directly useful in a wide range ofapplications.

On completion of this unit the candidate will be able to deduce design data from statically loadedcomponents and structures subject to bending and twisting. The candidate will be able to analyseloading systems and deduce the maximum stress which can be supported by the material.

In addition the candidate will be able to deduce or select the required cross-section of a loadedmember so that it will function safely.

GUIDANCE ON THE CONTENT AND CONTEXT FOR THIS UNIT

Computer software should be used where appropriate.

The importance of using appropriate units and British Standard recommendations, includingappropriate sign conventions, should be stressed throughout the presentation.

All diagrams should be in good proportion and drawn to scale when necessary.

Some time should be spent showing that both shear force and bending moment exist at any pointalong a loaded beam or cantilever. This will lead naturally to showing how these effects can best berecorded diagrammatically. Once these skills have been mastered the mathematical relationshipbetween shear force and corresponding bending moment can be explored, relating the slope of thebending moment diagram to the value of the shear force and the area of the shear force diagramrepresenting the change in the bending moment value. The position of turning points on the bendingmoment diagram occurring at zero shear will follow from this approach. Loading not perpendicularto the axis of the beam can now be introduced, and thrust diagrams of a simple nature attempted.

A series of graded examples supported by tutorial work should ensure appropriate progress is made.

Some time should be spent in close examination of the simple bending equation, considering the unitsused for each parameter and limitations of use as a consequence of the assumptions made.Determination of centroids and second moments of area using first principles should be restricted tovery simple cross-sectional areas. This information should be extracted from British Standards ormanufacturers’ data for more complex cross-sections.

Problem-solving should mainly lead to bending stress distribution across the cross-section or radius ofcurvature at the position of maximum bending stress along the section.

Some time should be spent in close examination of the simple torsion equation. Polar secondmoments of area should be calculated initially and subsequently extracted.




Problem-solving should mainly lead to torsional stress distribution across the cross-section and angleof twist along the length of the shaft.

Outcome 4 should be used to relate the theories developed in the other outcomes to practicalsituations where a suitable design stress has to be deduced allowing for the nature of the loading,environmental factors and material behaviour. Stress induced in components due to temperaturechange and subjected to complete or partial restraint should be introduced at this time. Elementarytheories of combined loading can be introduced as appropriate, and a suitable range of perhaps foursuch applications could be analysed with the candidates working in small groups using theteacher/lecturer as a consultant.

A comprehensive material properties database should be available either as software or as constantlyavailable reference materials.





The content statements given in the left-hand column of the following table describe in detail what thecandidate should be able to do in demonstrating knowledge and understanding associated withstrength of materials.






Simply supported beams and cantilevers

1 Calculation of reactions.

2 Construction of bending moment, shear forceand thrust diagrams.

Simple bending theory

1 Familiarisation with the simple bendingequation.

2 Solve problems associated with the simplebending theory.

The torsion equation

1 Familiarisation with the simple torsionequation.

2 Solve problems associated with the simpletorsion theory.

Design components

1 Extracting material properties fromdatabases.

2 Deduce design stresses.

3 Analyse loading conditions.

By taking moments or using force balances.

Diagrams are to include point loads, uniformlydistributed loads, turning points, zero shear,points of contraflecture.

All parameters are to be identified by words andsymbols, correct units for all values. Calculationof the second moment of area/section modulusfor simple cross-sections.

These should include the determination of thestress distribution across the cross-section of thebeam.

All parameters are to be identified by words andsymbols, correct units for all values. Calculationof the polar second moment of area for simplecross-sections restricted to solid and hollowcircular shafts.

These should include the determination of thestress distribution across the cross-section of theshaft.

Minimum of six materials to be considered. Theproperties should include elastic limit or proofstress, ultimate strength, moduli of elasticity andrigidity.

Deductions should take into account loadingconsiderations, environmental effects, cycliceffects and shearing situations.

To include any two combined effects.





Outcome 1

One loaded beam and one loaded cantilever should be presented to the candidate, requiring reactionsto be calculated in each case. It is only necessary for other features such as a thrust diagram, positionof maximum bending moment, position of contraflexture and the effect of a couple to be included ifappropriate. The shear force and bending moment diagrams should be sketched in good proportionand annotated in each case.

Outcomes 2

For one beam and one cantilever the candidate is required to apply simple bending theory todetermine the distribution of bending stress across the cross-section. The position of maximumbending moment and the corresponding radius of curvature should be determined. There is norequirement to produce bending moment diagrams again, and the same members used for Outcome 1can be employed if desired.

Outcome 3

For a shaft made up from partly solid circular section and partly hollow circular section, the candidateis required to apply the simple torsion equation to determine the stress distribution across bothsections of the shaft and the inclusive angle of twist along the length of the complete shaft.

Outcome 4

For each of the two components subjected to combined loading, the candidate is required to deduce asuitable design stress, select the mathematical model to be used for solution, and calculate a safecross-section for the member. This result can then be used to select an appropriate form of materialsupply.

SPECIAL NEEDS



Superclass: RC



Version: 03




32


UNIT Thermofluids (Higher)

NUMBER D162 12


SUMMARY

This unit focuses on applying the gas laws and properties of vapours to solve simple, steady flow,energy equation problems. This unit would be useful to candidates who require to apply engineeringprinciples to thermodynamic systems. Much of the content is directly useful over a wide range ofapplications.

OUTCOMES

1 Apply gas laws.2 Solve problems using data extracted from thermodynamic property tables.3 Solve problems associated with steady flow energy equation applications for gases and vapours.4 Apply the mass continuity and Bernoulli’s equations to flow through pipes.5 Solve problems associated with the behaviour of liquids at rest.

RECOMMENDED ENTRY




Mechanical Engineering: Unit Specification – Thermofluids (H) 33

National Unit Specification: general information (cont)


CREDIT VALUE

1 credit at Higher.

CORE SKILLS



Core skills components for the unit Numeracy H






OUTCOME 1

Apply gas laws.


(a) Each parameter, term and relationship of the gas laws is accurately identified.(b) Gas laws are applied correctly to solve problems.(c) A practical exercise involving the application of the gas laws is satisfactorily undertaken.

Notes on range for the outcome

Gas laws: Boyle’s Law, = Constant, characteristic equation.

Parameters: pressure, volume, specific volume, temperature, mass, universal gas constant.

Problems: internal combustion engines, nozzles, gas turbines.


Evidence that the candidate can apply a gas law to one practical situation, investigating changes intwo properties of a gas and keeping the third constant.Short answer questions should be used to cover remaining gas law and parameters.

OUTCOME 2

Solve problems using data extracted from thermodynamic property tables.


(a) Data is accurately extracted from thermodynamic tables for water and refrigerants.(b) Intermediate values of data extracted from the tables are interpolated correctly.(c) Problems are solved correctly using data extracted and suitably converted with respect to units.


Data: wet vapour, superheated vapour, internal energy, enthalpy, specific volume.Problems: steam generation, refrigeration.


Written and/or oral evidence which satisfies the PCs and the range as applied to wet vapour andsuperheated vapour.

PV T




OUTCOME 3

Solve problems associated with steady flow energy equation applications for gases and vapours.


(a) Common thermodynamic devices are correctly converted into input/output subsystemdiagrams.

(b) Each parameter, term and relationship of the steady flow energy equation is accuratelyidentified.

(c) Problems are solved correctly using the steady flow energy equation for gases and vapours.


Gases and vapours: air, steam.System parameters: input, output, process.Energy equation parameters: potential energy, kinetic energy, internal energy, flow energy, enthalpy,work, heat, losses.Thermodynamic devices: boiler, heat exchanger, turbine, compressor.

Evidence tequirements

Written and/or oral evidence which satisfies the PCs and the range as applied to one application for airand one for steam.

OUTCOME 4

Apply the mass continuity and Bernoulli’s equations to flow through pipes.


(a) Each parameter, term and relationship of the mass continuity and Bernoulli’s equations is accurately identified as applied to incompressible fluid flow.

(b) Flow through equipment is correctly described with respect to the interrelationship of the parameters.

(c) Problems involving fluid flow through a pipe of changing cross-sectional area are solved correctly as applied to incompressible flow.


Mass continuity equation parameters: mass flow rate, specific volume, cross-sectional area, velocity.Bernoulli’s equation parameters: pressure or flow energy, kinetic energy, potential energy,unaccountable loss of energy.Description of the operation of: a venturimeter, an orifice pipe.


Written and/or oral evidence which satisfies the PCs and the range as applied to one application ofincompressible fluid flow through a pipe of directly variable cross-section with inlet and exit levels atdifferent heights. Evidence should include a description of the operation of a venturimeter and anorifice pipe.




OUTCOME 5

Solve problems associated with the behaviour of liquids at rest.


(a) Each parameter, term and relationship of the variation of pressure with depth from the freesurface of a liquid is accurately identified.

(b) Problems are solved correctly relating to manometry and force on submerged areas.


Parameters: force on submerged areas, position of centre of pressure, vertical plane surfaces only.Problems: U-tube manometers, surfaces with fluid pressure on one side only.


Written or oral evidence which satisfies the PCs as applied to one problem for each item in the range.







This unit would be useful for a candidate who requires to apply engineering principles tothermodynamic systems. Much of the content is directly useful in a wide range of applications. Oncompletion of this unit the candidate will be able to analyse the movement and changes in propertiesof working fluids as they proceed through thermodynamic equipment such as boilers, heatexchangers, turbines, compressors and the connecting pipework. Additionally the candidate will beable to calculate force caused by liquid pressure on submerged areas and convert manometer readingsinto the pressure they are measuring.

GUIDANCE ON THE CONTENT AND CONTEXT FOR THIS UNIT

A systems approach using an input, process, output approach should be employed throughout the unit.The importance of using appropriate units and sign conventions should be stressed.

Some time should be spent looking at the gas laws separately before introducing the candidate to thecharacteristic gas equation. A graded tutorial session should effectively develop the necessaryalgebraic manipulative skills and numeracy practice. One or two experimental demonstrations wouldthen allow the candidate to attempt application of the gas laws in a laboratory situation and allow theinterpretation of results and report writing to be completed.

Some time should be spent determining properties of liquids and vapours and differentiating betweengas and vapour to emphasise the reasons why properties of vapours have to be experimentallyconfirmed and recorded as a set of thermodynamic tables. This will lead naturally to using the tablesand mastering the techniques of interpolation, although double interpolation should only be brieflyintroduced. The assessment for Outcome 2 can be integrated with Outcome 3 or presented at thisstage.

Many candidates will be familiar with the systems approach to analysing devices, but a few examplesof this technique applied to common thermodynamic systems will give a natural lead to thedevelopment of the first law of thermodynamics and its application to steady flow systems. Closedsystems can be considered as a special case if desired, and the concepts of flow energy and enthalpydealt with in as direct and simple a manner as possible at this stage. The desire to add numbers tosystem diagrams and apply a calculations dimension to the steady flow energy equation should beresisted until the candidate is comfortable with the theory and the recently introduced energy terms.Once numbers have been introduced and the sign convention mastered, examples containing up tothree subsystems can be attempted. A suitable range of structured tutorial questions can then be usedto give experience and emphasise concepts such as isentropic and adiabatic operations.

The use of the mass continuity equations can be introduced at any appropriate stage, either duringapplications of the steady state energy equation or afterwards as a separate topic. They can then beapplied to a few common examples of thermodynamic systems as well as to flow through pipes.




An analysis of the characteristics of pressure should highlight the fact that it is equal in all directionsand always acts normally to boundary surfaces throughout a stationary fluid. This can be followed bya treatment of pressure at a depth below the free surface of a fluid. The piezometer tube can then beused as an introduction to manometry, with progression to exploring problems involving U-tubemanometers to determine gauge pressure in pipes and vessels. The process of adding atmosphericpressure to determine absolute pressure can also be explored at this stage. Pressure differencebetween two pipes should also be measured using a U-tube manometer. Density to specific weightconversions and pressure recorded as a ‘head’ of liquid should emerge as a range of examples areattempted.

Pressure exerted at a depth in a stationary liquid can then be extended to determine the thrust onsubmerged vertical plane surfaces, and the technique used to determine the position of the centre ofpressure established. Simple problems, for example force required to open hatches against waterpressure thrust on tank walls, can then be attempted and, if desired, combined with the conditions ofequilibrium.





The content statements given in the left-hand column of the following table describe in detail what thecandidate should be able to do in demonstrating knowledge and understanding associated withthermofluids.






The Gas Laws

1 Describe the individual laws.

2 Use the combined gas law.

3 Solve problems involving perfect gases.

4 Solve practical problems.

5 Practical work.

Properties of vapours

1 Extract data for thermodynamic propertytables.

2 Interpolation of values.

3 Solve problems using data from tables.

Steady flow energy equation (SFEE)

1 Input-output process approach is used todescribe common thermodynamic process.

2 Solve problems using SFEE.

3 Applications of the SFEE to analyse practicalsituations.

Boyle’s law or Charles’s law could be used asexamples.

= Constant, PV = mRT

To include the calculation of properties.

Internal combustion engines, gas turbines andnozzles.

Where possible, practical demonstrations shouldbe used.

Fluids should be limited to water and refrigerants.

Properties are to include saturation temperatureand pressure, internal energy, enthalpy specificvolume.

In undercooled liquid, saturated liquid, wetvapour, saturated vapour and super heater vapourconditions.

Restricted to enthalpy, internal energy andspecific volume.

Problems should include a change of phase.

Calculation of dryness fraction and degree ofsuperheat.

Problems should be broken down to simplifiedInput/Output diagrams: for example boiler, heatexchanger or turbine.

Starting with problems that eliminate many of theenergy terms and increasing the difficulty to amaximum of three subsystems.

Analyse a practical situation using SFEE.

PVT





Flow through pipes

1 Derive Bernoulli’s equation from the SFEE.

2 Mass continuity.

3 Solve problems using Bernoulli’s equation.

Static fluid behaviour

1 Manometry.

2 Convert height differences to flow.

3 Relate pressure on submerged plates todepths.

Eliminate irrelevant terms and replace specificvolume with density.

To include inclined pipe, convergent anddivergent pipes, venturimeter, restricted toincompressible flow.

Piezometer tube, U-tube manometers only.

Calculation of thrust on submerged areas andposition of centre of pressure on submerged andpartially submerged plates. Restricted to pressureon one side only, and rectangular and roundplates only.


Outcome 1

A thermodynamic device fitted with appropriate instruments can be used to allow candidates to takereadings individually which can be compared with theoretical quantities derived by applying one ormore of the gas laws. The candidates should then be required to write a report, indicating theirfindings based on the interpretation and drawing comparisons of experimental and theoreticalproperties. The remainder of the range of this outcome would be covered by short answer questions.

Outcome 2

Tables of thermodynamic properties and given data should be used by the candidate to determinethree properties for wet vapour and two properties for superheated vapour. Interpolation betweenvalues in the tables should be included. This can be incorporated into the assessment for Outcome 3,if desired.

Outcome 3

For given data on two thermodynamic systems (one with vapour and one with air) considered assubsystems each using the same working fluid, the candidate is required to analyse the system. He orshe should insert properties in the system diagram and solve a problem using the steady flow energyequation to determine at least three parameters of the system; possibly a work quantity, heat transferquantity and an exit condition of the working fluid.




Outcome 4

For given data on flow through a pipe of different entry and exit cross-sectional areas, the candidateshould be asked to apply the mass continuity equation and Bernoulli’s equation. He or she shoulddetermine two parameters, possibly the mass flow rate and the velocity at exit.

Outcome 5

For given data concerning a mass of stationary fluid in a vessel, the force exerted on a submerged areasuch as a trapdoor or inspection cover could be calculated along with its point of application. Asecond problem could require the absolute pressure in a vessel to be determined using a U-tubemanometer. The barometric height of a mercury column could be used as the basis of the assessmentfor this outcome.

Although it would be possible to present the unit in an integrated way, working through the outcomesin sequence may be more desirable. The requirement for the candidate to be proficient in applying thegas laws and extracting data from thermodynamic tables before using the steady flow energy equationand mass continuity equation would argue against a holistic approach in this case. However, it wouldbe quite possible to integrate the assessment required for Outcome 2 with that for Outcome 3.

SPECIAL NEEDS


National Course Specification:All Units:Core skills statements expandedNational Course Specification (cont)

CORE SKILLSNational Course Specification: course details

SPECIAL NEEDSSUBJECT GUIDES

CORE SKILLSNote on range for the outcome

OUTCOME 3Outcome 1Outcomes 2 and 3Outcome 4

SPECIAL NEEDSCORE SKILLSOUTCOME 1OUTCOME 2Note on range for the outcome

Outcome 1Outcomes 2Outcome 3Outcome 4

SPECIAL NEEDSCORE SKILLSEvidence requirements

Outcome 1Outcome 2Outcome 3Outcome 4

SPECIAL NEEDS

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