Week 7 - CHT Analysis on a Graphics card

 OBJECTIVE

1. 1 Run the simulation by varying the velocity from 1m/sec to 5m/sec for at least 3 velocities and discuss the results.
2. 2 Find out the maximum temperature and heat transfer coefficient attained by the processor.
3. 3 Prove that the simulation has achieved convergence with appropriate images and plots.
4. 4 Identify potential hotspots on the model.

5. INTRODUCTION

7.  Conjugate Heat Transfer (CHT)

   Conjugate heat transfer is defined as the heat transfer between two domains by exchange of thermal energy. For a system the thermal energy available is defined by its temperature and the movement of thermal energy is defined by its heat flux through the outer walls. Heat transfer in solid happens through conduction and walls by convection and in liquid phase through convection.

   CHT provides the temperature prediction and the hotspot regions at the solid-fluid interface and we can also predict the heat transfer accurately for example- Conduction through solids, convection through fluid, and thermal radiation. It also provides the velocity and pressure distribution of fluid moving inside the solid. We can also use CHT in design optimization for improvement for heat transfer and cooling capacity.

    

    A video card (also called a graphics card, display card, graphics adapter, or display adapter) is an expansion card that generates a feed of output images to a display device (such as a computer monitor). Most video cards are not limited to a 6-inch simple output. Their integrated graphics processor can perform additional processing, removing this task from the central processor of the compute

8. SPACECLAIM GEOMERTY
9. 
10. Import Model:-
11. Base:-
12. 
13. Processor
14. 
15. Fins
16. 
17. Share Topology.
18. 
19. Baseline Setup :-
20. Meshing
21. Name of the component.
22. Inlet:-
23. 
24. Outlet:-
26. 
27. Symmetry Wall
28. 
29. Fins
30.  
31. Processor:-
32. 

Base :-

Base Mesh

A basic mesh is generated using the standard values recommended by Ansys. This mesh is used to obtain an initial solution which will help us to determine the location where mesh refinement is required.

Element Order: Linear

Element size: Default

Number of Nodes: 15769

Number of Elements: 84067

1. 
2. 
3. Simulation Setup.
4. first updae the mesh.
5. 
6. Setup:-
7. 
9. 

10. 1.Solver: Steady

    2.Type: Pressure Based

    3.Turbulence Model: k-Omega(SST)

    4.Materials: Different materials are used for each part, some of which are custom created

11. Parts                                                                                 Material
12. Base                                                                            polypropylene-b
13. Fin                                                                                 Aluminium
14. Processsor                                                                     Silicon
15. Encloser                                                                         Air
16. 
17. Material:-
18. Air:-
19. 
20. Aluminium:-
21. 
22. polypropylene-b
23. 
24. Silicon
25. 

    Boundaries:

    • Inlet:

                  Type: Velocity Inlet

                  Velocity: 1m/s

26.             Temprature-300K

27.  

    

28.  

29.  

    • Outlet:

                   Type: Pressure Outlet

                   Pressure: 0 Pa(Gauge Pressure)

                   Temperature: 300 K

30. 

31.  

    • Symmetry: Symmetry
    • Wall: Wall
    • 
32. cell zones base
33. 
34. 
35.  
37. 

The processor is assumed as the only source of heat. The heat generated by the processor is calculated as:-

 

Graphics Card Power = 10W

Volume of the card = 8 x 8 x 1

                            = 64mm3=64e-9m3">64mm3=64e−9m364��3=64�-9�3

 

Heat Generated = PV=1064e-9">PV=1064e−9��=1064�-9 

                   

                         = 1.5625e8Wm3">e8Wm3

e8Wm3">Solution:-

 

 

 

 Case-2 Inlet Velocity :-3m/s

Itration -500

 

 Case-3 

Velocity -5m/s

no of iteration-500

 

 

Results;-

Velocity                                      Surface Heat Transfer Cofficient  

1m/s                                                  -4.601508

3m/s                                                   -10.797145

5m/s                                                  -14.176637

 

Conclusion:-

1. Furthermore, it can be observed that the temperature of components increases as the inlet velocity decreases from 5 m/s to 1m/s, also proving that higher velocity results in better cooling.