Modelling and Analysis of a Cold plate cooling system using ANSYS Icepak

1. Problem description:

In this project, We are going to model and analyse a Cold plate cooling model using ANSYS Icepak. The model includes two heated plates, cooled by water circulating inside the cold-plate cavity, as well as by air driven by natural convection externally. Separately meshed assemblies will be employed to reduce the overall mesh count in the domain. The Model setup has been shown in the figure.

2. Geometry creation:

The Model has been created step by step asper the dimensions provided.

Cabinet:

• Size (400 mm X 300 mm X 200 mm)
• Cabinet opening: MinX and Max X - For the passage of air into the domain

Cold plate solid block: This is the Solid block going to enclose the fluid domain.

• Start (50 mm, 80mm, 70 mm)
• End (350mm, 220 mm, 130 mm)
• Made of aluminum extruded

Cold plate fluid block: A Block has been created as per the below mentioned dimensions and block type is changed as fluid.

• Start (60 mm 90mm, 80 mm)
• End (340mm, 210 mm, 120mm)
• Material: Water

Pipes:

A. Incoming pipe:

• Connected @ (100mm, 0 mm, 100mm)
• Radius: 15 mm
• Block type: Solid

B. Outgoing pipe:

• Connected @ (300mm, 0 mm, 100mm)
• Radius: 15 mm
• Block type: Solid

C. Fluid domain in pipe:

Two concentric cylindrical fluid domains are creates inside the solid pipes with a radius of 10mm as shown below.

Also, two cylindrical openings are provided at the start of inlet fluid pipe and end of the outlet fluid pipe to make the flow happen.

Conducting plates:

A. Hot Plate 1:

• Conducting thick 10mm
• Located at 60mm having dim (260 mm X 100 mm) in Z plane

B. Hot Plate 2:

• Conducting thick 10mm
• Located at 130mm having dim (260 mm X 100 mm) in Z plane

The Final Geometry setup created is as shown below.

3. Meshing the model:

All the components are added to a separate assembly and meshed with the parameters as shown below.

3.1. Global mesh parameters:

3.2. Assembly mesh parameters

Here, the slacks has been added to control the mesh bleeding in the domain and the mesh parameters used are shown below.

3.3. Mesh Quality:

All the Mesh qualities are under acceptable range. The lower limits of the metrics are listed below.

• Skewness - 0.267
• Face alignment - 0.455
• Volume - 2.1e-9

3.4. Visualising Mesh:

A. Fluids only

B. Solids only

4. Setting up and solving the case:

• The Conducting plates are provided with a heat source of 200W each.
• The Inlet Opening is provided with 0.2 m/s velocity and fluid material is chosen as water.
• The Ambient condition is set to 20 degC with default fluid material as air.

4.1. Basic solution settings

4.2. Discretisation schemes

4.3. Under relaxing parameters

After setting up the case, various solution monitor points are added to check for convergence.

4.4. Residual plot:

The Soultion has been started and got converged nearly at 450 iterations. The Residual plot has been attached below for reference.

5. Solution description:

5.1. Volume rendering:

The objects are coloured with temperature and the maximum temperature in the objects is 33.0012 degC

5.2. Cut plots:

A Cut plot has been created at XY plane for visualising the temperature and velocity distribution over the domain.

The Temperature cut plot shows the effect of conduction in the outer solid block due to hot plates attached to it.

As per the velocity contour, the Maximum attained velocity is 0.234m/s and the velocity distribution pattern can be easily seen.

Due to the natural convection, we can observe some velocity outside the solid block.

The Contour below shows the temperature distribution on the XZ plane to visualise the intensity of temperature transferred from hot plates to the fluid block.

5.3. Report summary:

6. Conclusion:

The Cold plate model has been modelled in Icepak and analysed for Natural convection successfully. As per the study, the system can attain a maximum temperature of 33.8812 deg C when water is used as a coolant in an ambient condition of 20 degC.