STEADY STATE ANALYSIS OF GRAPHICS CARD
STEADY STATE ANALYSIS OF GRAPHICS CARD
Objective:- To perform steady state analysis of graphics card.
Case 1:
A STEADY STATE ANALYSIS of graphics card is done using ANSYS FLUENT. Inlet velocity= 2 m/s, Temperature= 300 K.
Model
The model was imported in Spaceclaim. Model consists of fins base, processor, fins. The model is enclosed with a enclosure. The fins base, processor, fins and enclosure are divided into solid and fluid volumes. Volume= 64 x 10-9 m3.
Mesh
The model was meshed using ANSYS mesher with element size of 0.010289 m which the BASELINE mesh.
A mesh metric that identifies elements according to their quality was employed and it can be seen that the elements of lowest quality are minimal. Most of the elements have very high quality in the range of 0.65-1. Hence, the mesh is of acceptable quality. The meshed model is shown in image below. Number of Elements= 83843, Nodes= 15701.
Setup
Here we do Conjugate Heat Transfer Analysis (CHT) as there is heat transfer from processor which is the heat generating source to fins base and fins. The air flowing over gets heated up as it comes in contact the graphics card. Materials used are Fins base- Aluminium, Fins- Copper, Processor- Gold, Fluid- Air.
Volume = 64 x 10-9 m3, Input power= 15 W, Heat generated= 234375000 W/ m3.
Convergence
Iteration= 500 were ran. Convergence=80. The residual plot is plotted in ANSYS FLUENT shown below.
Result
Temperature Contour
Streamline Temperature Plot
Streamline Velocity Plot
Plane Velocity Plot
Heat Transfer Coefficient on the Plane
HOTSPOT
The hotspot regions are the fins and fins base which are in contact with the processor which is the heat source.
Case 2:
A STEADY STATE ANALYSIS of graphics card is done using ANSYS FLUENT. Inlet velocity= 2 m/s, Temperature= 300 K.
Model
The model was imported in Spaceclaim. Model consists of fins base, processor, fins. The model is enclosed with a enclosure. The fins base, processor, fins and enclosure are divided into solid and fluid volumes. Volume= 64 x 10-9 m3.
Mesh
The model was meshed using ANSYS mesher with element size of 0.004 m. Body mesh is applied to the fins base, fins, processor so that we get refine mesh on the body to get accurate result of heat transfer. Body mesh= 0.0006 m
A mesh metric that identifies elements according to their quality was employed and it can be seen that the elements of lowest quality are minimal. Most of the elements have very high quality in the range of 0.7-1. Hence, the mesh is of acceptable quality. The meshed model is shown in image below. Number of Elements = 497144, Nodes =86506.
Setup
Here we do Conjugate Heat Transfer Analysis (CHT) as there is heat transfer from processor which is the heat generating source to fins base and fins. The air flowing over gets heated up as it comes in contact the graphics card. Materials used are Fins base- Aluminium, Fins- Copper, Processor- Gold, Fluid- Air.
Volume = 64 x 10-9 m3, Input power= 15 W, Heat generated= 234375000 W/ m3.
Convergence
Iteration= 500 were ran. Convergence=80. The residual plot is plotted in ANSYS FLUENT shown below.
Result
Temperature Contour
Streamline Temperature Plot
Streamline Velocity Plot
Plane Velocity Plot
Heat Transfer Coefficient on the Plane
HOTSPOT
The hotspot regions are the fins and fins base which are in contact with the processor which is the heat source.
Difference in results in case 1 & case 2
|
CASE 1 |
CASE 2 |
|||
|
MAX |
MIN |
MAX |
MIN |
|
|
TEMPERATURE (K) |
436.7 |
299.8 |
413 |
300 |
|
VELOCITY (m/s) |
2.331 |
0 |
2.561 |
0 |
|
HEAT TRANSFER COEFFICIENT (W/m2 K)
|
958.1 |
0 |
604.3 |
0 |
From the above table we can see the following:-
- The maximum temperature decreases after the refinement of mesh.
- With refinement there is some increase in the maximum velocity occurred in the flow.
- With refinement the maximum Heat Transfer Coefficient occurred in the flow decreases.
Conclusion
The refinement done in the mesh gives accurate results which can be verified using the mentioned methods.