KB7001 Computational Fluid Dynamics and Heat Transfer.
Assignment - Design and validation of a heat sink
Assignment Brief - Design and validation of a heat sink
Problem Statement
An isothermal silicon chip of W = A mm and Z = B mm is soldered to a heat sink of equivalent size and generates heat at a rate of qc = C W (total), as shown in Figure 1. The heat sink needs to be designed so that the chip`s temperature Tc remains below 80 0C when the ambient temperature is 30 0C.
Part 1. Two-dimensional heat sink analysis using numerical finite-difference method
Using information provided in the "Problem Statement" section, "Design constraints" section and in "Parameters" table, determine the following:
1. Taking advantage of symmetry, discretise the heat sink geometry and write 2-dimensional finite- difference equations for each node.
2. Rewrite the equations of (1) in Gauss-Seidel form.
3. Determine the 2-dimensional temperature distribution in the heat sink using Gauss-Seidel method. Continue iterations until the node temperature difference between final iteration and previous iteration is less than 0.2C.
4. Determine the total heat loss per heat sink length.
Part 2. Three-dimensional heat sink analysis using analytical method and ANSYS numerical method
As an engineer assigned this task and using information provided in the "Problem Statement" section, "Design constraints" section and in "Parameters" table, determine the following:
Develop at least 3 different designs and evaluate their performances and cost for each design. For material selection, you can refer to the Table "Material data". For the final selected design you must investigate how changes in both the fin length and the convective heat transfer coefficient affect the heat transfer rate in the heat sink, and which parameter (h or Lf) has a greater effect on performance of the heat sink.
Using analytical method.
1. Include the details of the model and analytical equations you have used to evaluate three different heat sink designs. Each design must have different fin cross sections.
2. Any assumptions you have made must be stated.
3. Select the final heat sink design and justify why this design was selected.
4. For selected final design, perform Parametric Study and investigate the effect of varying convection coefficient (h) and fin length (Lf) on heat transfer and justify your results.