Computational Fluid Dynamics

1. Computational Fluid Dynamics Dr. Ugur GUVEN Professor of Aerospace Engineering(Ph.D) Nuclear Technology Engineer (M.Sc, PA)

2. What is Fluid Dynamics • Fluid Dynamics is the study of fluids (liquids and gases) under various conditions to see how they will behave. • Fluid dynamics allow us to examine the interaction between solid bodies and fluids so that their dynamics can be worked out for engineering purposes.

3. Areas of Fluid Dynamics Fluid dynamics encountered in everyday life include: • • meteorological phenomena (rain, wind, hurricanes, floods, fires) • • environmental hazards (air pollution, transport of contaminants) • • heating, ventilation and air conditioning of buildings, cars etc. • • combustion in automobile engines and other propulsion systems • • interaction of various objects with the surrounding air/water • • complex flows in furnaces, heat exchangers, chemical reactors etc. • • processes in human body (blood flow, breathing, drinking . . . ) • • Any physical process where fluids are involved

4. Approaches to Fluid Dynamics • There are three approaches to fluid dynamics: a) Theoretical Approach (The usage of Energy, Mass, Momentum equations) b) Experimental Approach ( The usage of experimental data for determining fluid behavior) c) Computational Approach (The usage of Numerical Methods, Computer Programming and Computer Simulation Software for Fluid Dynamics)

5. What is CFD? • Computational Fluid Dynamics (CFD) provides a qualitative (and sometimes even quantitative) prediction of fluid flows • CFD enables scientists and engineers to perform ‘numerical experiments (i.e. computer simulations) in a ‘virtual flow laboratory’ real experiment CFD simulation

6. Why Use CFD? • Numerical simulations of fluid flow (will) enable • • architects to design comfortable and safe living environments • • designers of vehicles to improve the aerodynamic characteristics • • chemical engineers to maximize the yield from their equipment • • petroleum engineers to devise optimal oil recovery strategies • • surgeons to cure arterial diseases (computational hemodynamics) • • meteorologists to forecast the weather and warn of natural disasters • • safety experts to reduce health risks from radiation and other hazards • • military organizations to develop weapons and estimate the damage

7. Examples of CFD

8. Examples of CFD

9. Examples of CFD (Other Fields)

10. Examples of CFD (Manufacturing)

11. Examples of CFD (Medical)

12. Examples of CFD (Medical)

13. Examples of CFD (Other Fields) Smoke plume from an oil fire in Baghdad CFD simulation

14. Experiments vs. Simulations CFD gives an insight into flow patterns that are difficult, expensive or impossible to study using traditional (experimental) techniques

15. Experiments vs. Simulations

16. Approaching a CFD Problem CFD Problems must be approached with the following methodology: 1) Problem must be defined using equations of Fluid Dynamics (such as the Navier Stokes Equations) 2) Equations will have to be solved with numerical approximation methods with as much iteration methods as possible. 3) FORTRAN or other scientific computer programming languages can be used to solve these fluid dynamics equation with numerical methods. 4) Fluid Dynamics & Heat Transfer Simulation Software such as ANSYS (FLUENT) or STAR is used to simulate the necessary parameters graphically.

17. CFD Analysis Process

18. CFD Computing Power • For detailed and realistic analysis of CFD problems, often clusters of computers are needed. Even with the computers below a CFD model preprocessing can take weeks.

19. Quality of the Simulation in CFD

20. Fluid Characteristics

21. CFD Tools • Some popular CFD Software that you need to learn are: a) GAMBIT for Drawing the System b) FLUENT for Processing the Results (ANSYS is the name of the whole package) c) OPENFOAM for CFD applications in UNIX d) FEMLAB for Heat Transfer and Flow Applications e) FEATFLOW for CFD applications in a mainframe environment.