Mesh optimisation and Thermal Analysis of Hanging node assembly

1. Problem description:

In this project, we will be analysing the hanging node assembly provided. Without any modifications, the model results in about 750,000 elements. Note that this mesh count results from using the non-conformal meshing technique, which reduces mesh bleeding and mesh count. However, this mesh does not fully resolve the fine-level geometric features of the CAD objects.

We have to reduce the mesh count and improve the mesh resolution on and around the CAD objects by using the multi-level meshing technique. This procedure starts with a coarse background mesh and resolves fine level features through a series of successive mesh refinements. By using multi-level meshing and the uniform mesh parameters feature, you can reduce the mesh count to approximately 600,000 elements and improve mesh resolution.

2. Mesh information at initial stage:

• Number of elements: 714139
• Skewness:
• Face alignment:

Steps taken to reduce the Mesh count:

1. Meshed the Fan assembly separately by adding slack and Hexa unstructured mesh with small change in global mesh values.

2. Added Multi level mesh of 2 to the fan object.

3. After these two steps, the mesh count has been reduced to 675920, but still we can observe there are more skewed cell in the fan assembly especially in flow guide. So, the multi level mesh has been added to the necessary objects.

4. Similarly, other assemblies are also checked and optimised with per-object parameters and multi-level meshing.

5. After repetative combinations, the skewness in the domain has been reduced and we can observe approx 100 cells (previously it is 250 cells) are below the limit of 0.1 which is 0.016% on the total cell count. (Total mesh count is 6.18L)

• Skewness: 0.0059
• Face Alignment : 0.187
• Min Volume : 4.3e-13

2.2. Visualising the mesh:

A. Mesh Along XY Plane:

B. Mesh along XZ Plane:

C. Mesh in Sheetmetal_HS:

3. Solving the case setup:

The Provided model has a pre-defined case setup with sources and flow characteristics, hence proper monitor points and groups are created to ensure convergence and analysing results respectively.

A. Basic paramters:

B. Basic settings:

C. Advanced settings:

D. Residual plot:

E. Monitor point plots:

For Temperature:

For Velocity:

4. Solution description:

A. Contour plots of Temperature and Velocity distribution:

Here we can clearly see the CPU and fins assembly has a max temperature of 60 degC apprx, but the Sheetmetal_HS assembly is affected with high temperature of 111.336 degC at the base area as the flow is obstructed to its base by another component infront of the assembly.

B. Temperature distribution in Sheetmetal_HS:

C. Temperature distribution of DIMM assembly:

As five heat sources of 2W each are situated inside the DIMM assebly, the temperature raised to nearly 200 degC.

D. Flow pattern:

This Picture represents the flow pattern from the fan to the grilles on the temperature object face contour.

E. Report data:

6. Conclusion:

The Hanging node assembly has been meshed optimally and analysed for the forced convection successfully. The CPU assembly is forced cooled, hence its under temperature range of 50 degC, but the Sheetmetal HS assembly's base is affected by a temperature of 110 degC due to obstruction to the flow by a component placed before it. Considering the relocation of the component, provided more effective cooling. Also, some sort of convection has to be provided to the DIMM assembly as its containing 5 heat sources within a restricted passage, the maximum temperature in that assembly is 196.66 degC, which is not a safe range.

END OF THE REPORT