Conjugate Heat Transfer Analysis on a graphics card.
Aim: conjugate heat transfer analysis on graphic card
we can divide this methodology into given parts
- Why graphic card used
- Fluent setup for baseline mesh
- Fluent setup for refined mesh
- Fluent setup for different velocities
- Conclusion
Why graphic card is used?
The Graphics Card is responsible for rendering an image to your monitor, it does this by converting data into a signal your monitor can understand. The better your graphics card the better, and smoother an image can be produced. This is naturally very important for gamers and video editors.
Here for an example considering graphic card has a TDP (Thermal design power) of a 10 W.
- Fluent setup
Space claim setup
Uploading the given graphic card 3d model in space claim,
Topology sharing is enabled for non-conformal mesh
- Meshing ideology
Uploading the file into mesh setup for the baseline mesh
element size 10mm(baseline mesh default size)
- fluent setup
PCB MATERIAL : COPPER
FINS: ALUMINIUM
PROCESSOR :ALUMINIUM
Here, aluminum and copper both have higher thermal conductivity, which means it will transfer higher heat to adjacent material. copper conductivity is 385 w/m.k ad aluminum has 205 w/m.k. As aluminium is lighter and cheaper, we are using aluminum as a majority purpose.
First case
Inlet velocity : 5 m/s
energy equation with K-e model is used.
cell zone conditions have been divided into fluid and solid parts. Heat generation rate is given in terms of w/m3 for processor which is 156250000w/m3.
Residuals
Around 200 integration solution has been converged
Max temp is 85 C
Velocity graph
wall htc
max value 940w/m2.k
temp contour
Middle region has highest temperature and once it travels far away from heat source it is decreasing.
Refined mesh for velocity 5m/s.
Method : quad
element size : 0.5mm
It converges after 200 itetration
Post processing
Max temp : 66 degree
WALL HTC
Max wall htc 1320 w/m2.K
Streamline graph:
Velocity contour
Velocity 1 m/s refine setup
Temp contour
Max temp 166 degree celcius
Velocity 3 m/s refined setup
Temp contour
Max temp is 83 degree celcius
Max wall htc 1320 W/m2.K
Velocity streamline
Velocity graph
Velocity contour
- Values of temp and wall HTC for different cases.
Hotspot regions
From the temp contour, we can see that hotspot regions for max temp are near the processor. HIghest temp attained by the component is the processor as it is heat source
Conclusion
- From the values and hotspot regions, we can conclude that by increasing the velocity heat transfer coefficient value will be increased and max temp attained by the system will be decreased
- From the hotspot region, we can conclude that the electronic component is placed far from the processor to get lower heat.heat sink is basically placed to get higher surface area and lower the temp, once we increase the fins graphic card will cool down faster.
- If the material is selected with high thermal conductivity, it will take lesser time to cool down, But cost of high conductive material will be higher, i.e. copper
- Hence the temp of graphic card is depend on placing of fan , number of fan , Material , number of fins and type.