Week 6 - CHT Analysis on a Graphics card
CHT Analysis on a Graphics card
Objective:
In this challenge our objective is to perform a steady state simulation of a conjugate heat transfer in a graphics card. We will be running the simulation for default mesh and refined mesh. The air flow over the surface is varied from 1m/s to 5m/s.
From this simulation we want to find, the hotspots and heat transfer co-efficient for the heat tranfer process.
Introduction:
Graphics card (also called a video card, display card, graphics adapter, or display adapter) is an expansion card which generates a feed of output images to a display device (such as a computer monitor). These graphics card generates heat when under operation. The graphics card generates heat while under operation. This heat is moslty generated in the processor. The heat generated must be removed from the processor. For this purpose heat sink is provided. A heat sink is mounted on most modern graphics cards. A heat sink spreads out the heat produced by the graphics processing unit evenly throughout the heat sink and unit itself. The heat sink commonly has a fan mounted as well to cool the heat sink and the graphics processing unit. The heat sink is moslty fins made of aluminium. These increase the heat tranfer area and hence helps in heat transfer process. Fans are employed to increase the heat transfer co-efficient. The entire setup is arranged on pcb made up of fiber glass. The processor is made of silicon material. We will be using the following material for our simulation.
Graphics cards generally looks like
Steps Followed:
a) Geometry Preperation
b) Meshing
c) Setup
d) Results
a) Geometry Preperation:
Already available model of Graphics card was used for the simulation. In spaceclaim the model was imported.
b) Meshing:
Creating named selctions.
Basic Mesh:
The Mesh is conformal.
Refined Mesh:
c) Setup:
In setup
select pressure based steady state solver
Energy equation is enabled
K-epsilon standard model
In material use air and aluminium. Create new material which are not present in the data base for base and processor.
Give appropriate conditions for cell zones and boundary conditions.
In solution
select hybrid initialization and initialize the solution.
In results
Create planes and contours.
In solution
Create animations
Materials:
Cell Zones:
Boundary conditions:
d) Results:
For Course Mesh with 1m/s velocity input:
Refined Mesh with 1m/sec velocity input:
Refined Mesh with 3m/sec velocity input:
Refined Mesh with 5m/sec velocity input:
Conclusion:
The following results were obtained.
| Inlet Velocity | Maximum Temperature |
| 1m/sec (Basic Mesh) | 319.5183 |
| 1m/sec (Refined Mesh) | 317.0809 |
| 3m/sec (Refined Mesh) | 309.3875 |
| 5m/sec (Refined Mesh) | 307.3508 |
The maximum temperature keeps decreasing with increase in velocity, due to increase in heat transfer co-efficient.
The maximum temperature (hotspot) always occur inside the processor, because it is the volume where heat is generated.