LABORATORY OUTCOME BASED ASSESSMENT GUIDELINE

TOPIC EXPERIMENT: BERNOULLI THEOREM

PROGRAM LEARNING OUTCOMES (PLO)Upon completion of the programme, graduates will be able to:1 Possesses and apply civil engineering knowledge2 Demonstrate technical skills in civil engineering3 Understand and commit professionally , ethically and humane responsibility, in line the code of

conduct4 Communicate effectively both in written and spoken form with other colleague and community5 Identify and provide creative, innovative and effective solution to civil engineering problems6 Recognise the need and to engage in, lifelong learning and professional development7 Self motivate and enhance entrepreneurship skill for career development8 Demonstrate leaderships skills to lead a team9 Work collaboratively as team members

COURSE LEARNING OUTCOMES (CLO) Upon completion of this course, students should be able to:- 1. Explain clearly the fluid characteristics, fluid pressure and solve problems in flow of fluid using

Bernoulli’s Equation.2. Apply principles to solve problems in laminar and turbulent flow and relation to Reynolds number, Darcy’s and Hagen-Poiseuille equation for problem solving.3. Apply correct methods and procedures of hydraulics solution towards practical problems.4. Acquire appropriate knowledge in minor loss in pipe and uniform flow in open channel

No. Lab.TitleTeachingMethod

PLO CLO GSA / LD

1.0Fluid Characteristics

Lecture,Q&A,

Demo AndLabo.

1&2 3 LD1 & LD 2

2.0Bernoulli Theorem

3.0Reynolds Number

4.0Fluid Friction Test

5.0Uniform Flow

Generic Student Attributes (GSA): GSA 1 Communications Skills GSA 2 Critical Thinking and Problem Solving Skills GSA 3 Teamwork Skills GSA 4 Moral and Professional Ethics GSA 5 Leadership Skills GSA 6 Information Management Skills and

Continuous Learning GSA 7 Entrepreneurship Skills

Learning Domain (LD):LD 1 Knowledge LD 2 Technical Skills LD 3 Professionalism and Ethics LD 4 Social Skills and

Responsibilities LD 5 Communication Skills LD 6 Critical Thinking LD 7 Life Long Learning LD 8 Entrepreneurial Skills LD 9 Teamwork / Leadership Skills

NO. EXPERIMENT : 2

TOPIC EXPERIMENT : BERNOULLI THEOREM

INTRODUCTION :

This experiment is carried out to investigate the validility of Bernoulli’s theorem

when applied to the steady flow of water in tapered duct and total pressure heads

in a rigid convergent/divergent tube of known geometry for range of steady flow

rates . The Bernoulli’s theorem relates the pressure , velocity and elevation in a

moving fluid ( liquid or gases ) , the compressibility and viscosity ( Internal friction )

which are negligible and the flow of which is steady , or laminar .

Bernoulli's principle can be applied to various types of fluid flow, resulting in what is

loosely denoted as Bernoulli's equation. In fact, there are different forms of the

Bernoulli equation for different types of flow. The simple form of Bernoulli's

principle is valid for incompressible flows (e.g. most liquid flows) and also for

compressible flows (e.g. gases) moving at low Mach numbers (usually less than

0.3). More advanced forms may in some cases be applied to compressible flows at

higher Mach numbers (see the derivations of the Bernoulli equation). Bernoulli's

principle can be derived from the principle of conservation of energy. This states

that, in a steady flow, the sum of all forms of mechanical energy in a fluid along a

streamline is the same at all points on that streamline. This requires that the sum

of kinetic energy and potential energy remain constant.

OBJECTIVE : To investigate the validity of Bernoulli’s Theorem

and Pressure measurements along venturi tube.

APPARATUS : Hydraulic bench

Bernoulli’s Theorem Demonstration apparatus.

Stop watch

Figure 1: Bernoulli’s Theorem Demonstration Apparatus

1. Assembly board

2. Single water pressure gauge

3. Discharge pipe

4. Outlet ball cock

5. Venturi tube with 6 measurement points

6. Compression gland

7. Probe for measuring overall pressure (can be moved axially)

8. Hose connection, water supply

9. Ball cock at water inlet

10. 6-fold water pressure gauge (pressure distribution in venture tube)

THEORY :

The measured values are to be compared to Bernoulli’s equation.

Bernoulli’s equation for constant head h:

Allowance for friction losses and conversion of the pressures p1 and p2 into static

pressure heads h1 and h2 yields:

p1 = Pressure at cross-section A1

h1 = Pressure head at cross-section A1

v1 = Flow velocity at cross-section A1

p2 = Pressure at cross-section A2

h2 = Pressure head at cross-section A2

v2 = Flow velocity at cross-section A2

= Density of medium = constant for incompressible fluids

such as water

hv = Pressure loss head

The venturi tube used has 6 measurement points. The table below shows the

standardised reference velocity . This parameter is derived from the geometry of

the venturi tube.

Point, i di (mm)

1 28.4

2 22.5

3 14.0

4 17.2

5 24.2

6 28.4

Multiplying the reference velocity values with a starting value, the student can

calculate the theoretical velocity values vcalc at the 6 measuring points of the venturi

tube.

At constant flow rate, the starting value for calculating the theoretical velocity is

found as:

The results for the calculated velocity, vcalc can be found in the table.

Calculation of dynamic pressure head:

80 mm must be subtracted, as there is a zero-point difference of 80 mm between

the pressure gauges.

The velocity, vmeas was calculated from the dynamic pressure

A

CONCLUSION

Bernoulli's principle can be used to calculate the lift force on an airfoil if the

behaviour of the fluid flow in the vicinity of the foil is known. For example, if the air

flowing past the top surface of an aircraft wing is moving faster than the air flowing

past the bottom surface, then Bernoulli's principle implies that the pressure on the

surfaces of the wing will be lower above than below. This pressure difference

results in an upwards lifting force. Whenever the distribution of speed past the top

and bottom surfaces of a wing is known, the lift forces can be calculated (to a good

approximation) using Bernoulli's equations established by Bernoulli over a century

before the first man-made wings were used for the purpose of flight. Bernoulli's

principle does not explain why the air flows faster past the top of the wing and

slower past the underside. To understand why, it is helpful to understand

circulation, the Kutta condition, and the Kutta–Joukowski theorem.

The carburetor used in many reciprocating engines contains a venturi to create a

region of low pressure to draw fuel into the carburetor and mix it thoroughly with

the incoming air. The low pressure in the throat of a venturi can be explained by

Bernoulli's principle; in the narrow throat, the air is moving at its fastest speed and

therefore it is at its lowest pressure.

The Pitot tube and static port on an aircraft are used to determine the airspeed of

the aircraft. These two devices are connected to the airspeed indicator, which

determines the dynamic pressure of the airflow past the aircraft. Dynamic pressure

is the difference between stagnation pressure and static pressure. Bernoulli's

principle is used to calibrate the airspeed indicator so that it displays the indicated

airspeed appropriate to the dynamic pressure