Numerical investigation of thermal and hydraulic performance in novel oblique geometry using nanofluid

Abstract

To capitalize the advantage of oblique fin heat sink (OFHS) with Al₂O₃–water nanofluids of different volumetric concentration (1, 2, and 4%), a comprehensive computational analysis has been performed for OFHS with nanofluid through the single-phase modeling. The present investigation focuses on the full domain simulation because the conventional periodic computational model approach is unable to investigate the flow migration effect and predicts higher value of Nusselt number. Apart from the disruption of boundary layer, vortices are observed in the secondary oblique channel due to flow separation that promotes an additional heat transfer enhancement. Higher Severity of the flow migration and hence more non-uniformity of nanofluid flow rate through the primary and secondary channels was observed at higher Reynolds numbers. The increment observed in the average Nusselt number (Nu_avg) at Re = 750 for OFHS is about 90% and 115% for water and 4% volumetric concentration of nanofluid respectively compared to conventional SCHS. Also, Al₂O₃–water nanofluid exhibits about 30% higher enhancement at 4% volumetric concentration at Re = 750 in the OFHS with compared to water. The increase in heat transfer exceeded the pressure drop penalty at all the Reynolds numbers.

Additional information

Funding

This work was supported by the Science and Engineering Research Board (SERB), Department of science and Technology, Govt of India under Grant Number [DST (SERB)/ECR/000176]. The authors also acknowledge IIT (ISM) Dhanbad for providing seed grant (FRS (94)/2015-2016/Mech. Engg.).