The Significant Effect of Secondary Flow in Wavy Microchannel for Augmentation of Heat Transfer

Abstract

The heat transfer augmentation methods have received a great attention from many researchers to enhance heat transfer in conventional thermal applications. Recently, many studies haveadopted passive methods to enhance heat transfer in microchannel heat sink. Channel curvature and secondary flow are two of the methods in which their effectiveness in this field have been proven. In the present study, a combination of these two methods was applied to enhance heat transfer rather than using individual method. Three-dimensional numerical analysis of conjugate heat transfer was conducted in a wavy microchannel with oblique secondary channel in alternating orientation (WAOC). The study presented the effects of three structural parameters on hydrothermal performance with the amplitude ranged from 0.05 mm to 0.2 mm, a secondary channel width between 0.1 mm and 0.2 mm, and an angle of inclination between 45° and 90°. The results were compared with wavy microchannel without secondary channel (WWOC) and also with straight microchannel of the same cross-section. The thermal performance of WAOC increased for about 108% with optimal structural parameters of 0.1 mm amplitude, 0.2 mm secondary width, and 45° angle of inclination. The results also revealed thatthe Nusselt number of WWOC increased for about 28.5% more than