CPU Heat Sink
Objective
In a four member team, we needed to design a heat sink to lower the temperature of a CPU to 80 °C, while finding a competitive edge over units being sold commercially. This would involve applying the concepts of conductive and convective heat transfer throughout the sink, and eventually modelling the process using Python.
Skills: Python, Heat and Mass Transfer Concepts, Numerical Methods
Spring 2022 - Summer 2022
Design Process
Our first steps were to layout the constraints of the project, which we determined to be the area and height of the base, along with the number of fins on the sink.
To achieve the optimal sink based on the constraints, a decision matrix was constructed, which considered the material, base thickness, fin arrangement, and additional attachments that would compose the most cost-efficient heat sink.
Next, we used Fourier and Newton’s laws of heat transfer, along with the heat continuity equation, to derive a series of equations to model the temperature profile of the sink.
The numerical methods approach of finite differences was then applied to the derived equations to generate arrays of temperatures that would be found throughout the sink. When transferring the arrays into code, the temperature profile over the component was yielded.
Exploded model of the heat sink component
Design chart to determine physical variables of the heat sink
Temperature profile from the CPU to the top of the heat sink
Results and Reflection
From the decision matrix, it was determined that the most cost-efficient design is an aluminum sink with 20 straight fins. This achieved a final price per unit of $0.25, highlighting a large price difference from commercial models, typically priced around $2-3.
Since this design was majorly theoretical, with assumptions and constraints to simplify the project into the realm of our heat transfer knowledge, the difference in price is a rough guideline to gauge our choices of physical variables, while still providing good performance.
Overall, my biggest takeaway from this project was the importance of laying out constraints before proceeding to work on a task. We initially had a lot of trouble foreseeing a method of comparing our design against existing ones, so we decided to constrain certain dimensions and number of fins.
This would put more emphasis on other variables such as material choice and base thickness, which ultimately allowed us to compare against similar heat sinks on the market.