Effects of splitter shape on thermal-hydraulic characteristics of plate-pin-fin heat sink (PPFHS)

Abstract

Previous studies Razavi et al. (2015) and Sajedi et al. (2016) have shown that the use of thin straight plates connected to pin-fins as splitters can weaken the flow separation and decrease the pressure drop through plate-pin-fin heat sinks (PPFHSs). In the current study, two new configurations of splitter, namely arched and wavy, are proposed to improve the overall hydrothermal performance of PPFHSs. In addition to the forward arrangement studied previously, the backward arrangement of splitters is also investigated here. The case under the consideration to implement the current idea is a PPFHS equipped with rectangular plate-fins and square pin-fins. Hence, six enhanced models are examined, and the obtained results are evaluated as compared with the smooth case. The working fluid is water in the Reynolds number range from 50 to 250. This analysis is carried out using 3D-numerical simulations, and the results are validated by the obtained experimental data as well as previously proposed correlations. It is found that the shape and arrangement of splitters affect considerably temperature contours and flow fields of the fluid through the PPFHS. Further, indirect splitters with forward arrangement lead to lower base temperature of the PPFHS in comparison with the straight one, however, an inverse trend is seen for the backward arrangement. The minimum base temperature is detected for the model having arched splitters with forward arrangement. At the studied range, the best overall hydrothermal performances are also reported for this model. For instance, the maximum value for one performance index is reported to be 1.36 at the minimum Reynolds number of 50.