Ch 0 Introduction PAT2

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AAS1, Lecture 0 1

Introduction

A.Asad SoniefScientific Computing Group

Department of Engineering

University of Brawijaya

Engineering Analysis

Simulation-modeling


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What is Engineering Analysis?

It is a vital TOOL for practicing

engineering professionals in performing

their duties in: Decision making

Problem solving

Creations

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Engineers create:

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Scientists DISCOVER what it was,Engineers CREATE what it is not

Engineers create what it is not in

DESIGN to satisfy human needs:


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Engineers make DECISIONS at all times, and

often crucial ones: Decisions are required in:

Design Configurations

Selection of design methodology, materials and fabrication

methods Assembly, packaging and shipping

Manufacturing Tools and machine tools

Fabrication processes

Quality control and assurance Maintenance Routine inspections and

Procedures

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Unexpected cases with potential grave

consequences

Change of customer requirements Malfunctioning of machines and equipment

Defections in products

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Engineers solve Problems often in ways

like fire-fighting:

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Simulation

What is numerical simulation?

Is it important?

Application examples

Simulation software


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What is Simulation?

Processes (natural, man-made, abstract/virtual)

Physical insight

Mathematical models (based on PDEs)

Numerical methods

Software implementation

Computer experiments

Interpretation of results (large amounts of numbers)

We define simulation as the process of exploring (mathematical)

models of natural or man-made processes by the means of a

computer.


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Development of theory

modeling experiment

simulation

Traditional development of models of a physical phenomenonModern development of models for a physical phenomenon


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The Simulation Pipeline

Prediction & Control

Refinement

Computations

Results

DATASET UNSTRUCTURED_GRID

POINTS 201 float

2.77828 2.18262 -0.25

0.476 2.4 -0.85 0.85 2.4

-0.476 -0.476 2.4 -0.85

-0.85 2.4 -0.476 -0.85

2.4 0.476 -0.476 2.4 0.85

0.476 2.4 0.85 0.85

2.4 0.476 2.55 0.8625 0.66

CELLS 458 2290

4 41 29 65 80

4 53 41 65 82

4 35 34 47 71

Processes

Mathematical Model


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The Real World in a Computer Test Tube?

Small cost compared with field experiments

Field experiments may be too dangerous Field experiments may be impossible

Provide better understanding of the processes

Provide tools for process prediction and control

...

Why should we make computer simulations?


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Simulation is reaching wide

Applications in: All engineering disciplines

Physics (astro, geo, nuclear,..)

Biology and medicine

Ecosystems and environment

Meteorlogy, oceanography,,

Financial and assurance market

. Always stretching the limits of what is computationally

feasible.

Observation: mathematics is a vital ingredient.


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Electrical Heart Activity

Simulation of the electrical activity in

the human heart based on a model

coupling several PDEs and ODEs.

The visualised electrical potential

represents a period of 250 ms. This

problem is extremely demanding in

terms of computational resources and

requires advanced solution methods

and fast hardware.


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Have you quit smoking?

Results from 3-D lungairflow modeling,

depicting flow velocity at

selected cross-sections

in a single bifurcation.

Computational fluid

dynamics (CFD)

techniques used in the

design of cars, airplanes

and aerospace vehicles

have been converted touse in the complex

branching geometry of the

lung's small airways.


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Aerospace and Automotive Industries

Car crash simulations


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Mathematic modeling

Mathematical modeling involves:

Translating a physical situation into

mathematical expressions It is a similar action of writing MUSIC from the

melodies in the minds of great composers,

e.g., Beethoven, Mozart, etc.

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Engineers duties include:

CREATION,

DECISION MAKING, and

PROBLEM SOLVING

Performing each of these duties involves a

process in reaching solutions The subjects in these processes are

translated into FUNCTIONS, and the

factors that affecting the values of these

subjects are VARIABLES.

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VARIABLES include:

Spatial variables: represented by

coordinate systems with set

reference points. Commonly used coordinate

systems are: (x, y, z) in rectangular coordinates, or

(r, , z) in cylindrical polar coordinates

Temporal variable: time (t) x,y,z and t are INDEPENDENT variables

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The process for solutions is to include the

FUNCTIONS with VARIABLE in

APPROPRIATE MATH MODELS, and reachmath solutions

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Frequent Functions in ME Engineering Analyses

Mass (m), weight (W), Length (L), Area (A),

Volume (V) of solids Forces (F)

Stress (), Strain () in deformed solids

Distance traveled by a moving rigid body (S) Temperature in solids and fluids (T)

Velocity of a rigid body or fluid (V)

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Properties of Functions

Functions may change their values with the

change of independent variables (spatial

and temporal) - So, functions are dependent

variables The value of a function is a CONSTANT-

depending on the values of the associated

independent variables.

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Reference

Tai-Ran Hsu, 2013-ed, Applied

Engineering Analysis, San Jose State

University Department of Mechanical andAerospace Engineering.

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Documents

Ch 0 Introduction PAT2