Microchannel Heat Sink Optimization: DOE Applying OSFD Method

Description

Description

In this project, we present the optimization process for improving the thermal performance of a microchannel heat sink using the Design of Experiment (DOE) in ANSYS software.

Microchannel heat sinks are suitable tools for dissipating the considerable heat generated by high-power electronic devices. Microchannel heat sinks are widely used because they have high heat transfer coefficients and large specific surface area.

The present microchannel heatsink has a solid zone body consisting of a cooling fluid channel with a porous medium. In general, microchannel heat sinks contain several channel rows. But for construction simplicity, we modeled only one section of the heat sink microchannel.

Methodology

We modeled a 3D microchannel heat sink in Design Modeler software and then meshed the model in ANSYS Meshing software.

We intend to optimize the design of a microchannel heat sink. Therefore, we defined 3 input parameters: Two geometric factors, including the length and height sizes of the rectangular cross-section of the cooling fluid channel, and one operating factor, i.e., porosity of the porous medium of the channel. Then, we defined the maximum temperature of the microchannel surface as the target output parameter.

We used the Design Exploration tool to perform the optimization process.

First, we start with the Design of Experiment (DOE). We generated the design points using the Latin Hypercube Sampling Design (LHSD). According to the maximum and minimum ranges for all three input parameters, 10 design points are generated.

Then, we continue with the Response Surface Methodology (RSM). We estimated the output parameter values ​​based on the Genetic Aggregation type.

Conclusion

According to the RSM, we obtained 2D and 3D plots of maximum temperature to analyze the simultaneous effects of the three input parameters. The results show that increasing the length, height, and porosity decreases the maximum temperature.

As the length and height of the cooling channel increase, the maximum temperature of the heat sink surface decreases. Increasing the length and height dimensions causes an increase in the cross-section of ​​the cooling channel and, consequently, the flow rate of the incoming fluid. Therefore, heat transfer is increased, and the cooling process is improved.

Increasing the porosity of the porous medium within the cooling channel reduces the maximum temperature of the heat sink. This is because utilizing a porous medium enhances the heat transfer process.

Also, note that the effect of porosity on the surface temperature of the heat sink is less than the dimensional parameters, including length and height.

In addition, we obtained the plots of the local sensitivity and goodness of fit. The local sensitivity shows how much each input parameter affects the output parameter. The goodness of fit shows the accuracy of the results estimated by RSM compared to the results obtained at the design points.