Search

Today, electronic device cooling is a significant challenge that has been addressed by utilizing heat sinks with various designs. The numerical and experimental investigation of changes in the wavy channel heat sink height is carried out to improve the performance. As a novelty, the heat sink's height remains constant to assess how open space above the channels affects the performance. The work aims to assess the impact of various heat fluxes and flow rates on temperature, Nu number, flow, and velocity; meanwhile conducting a non-dimensional analysis. At the flowrate of 6.94 cm 3 / s , once the channel's height was reduced to 10 mm, the highest temperature decreased by 7.84%, while by the decrement of height to 7 and 4 mm, it witnessed 14.14% and 23.81% rises, respectively. The local Nusselt number for 10 mm height and 19.56 cm 3 / s flow ranges between 127.47 and 106.53 in 5.17 W/cm2 heat flux. The flow with higher dimensionless velocity is dispersed throughout the open area above the heat sink, once the 12.7 mm height is reduced to 10 mm. The performance evaluation criterion of the system is determined by considering the ratio between Nu number and friction factor, which is obtained between 1.08 and 1.22 for 10 mm channel height. Thus, the 10 mm wavy channel height can be suggested for cooling electrical equipment. • Investigating channel height variations in constant-height heat sinks to determine open space impact above the wavy channel. • The wavy channel heat sink with 10 mm height shows higher performance due to flow mixing. • An analysis of velocity and temperature is provided using non-dimensional methods. • The performance evaluation criterion is compared for different channel heights while keeping the heat sink height constant. [ABSTRACT FROM AUTHOR]

Three-dimensional numerical computations are performed to investigate the performance of curved winglets mounted on a rectangular channel. The concave and convex shapes of curved rectangular winglet vortex generators (RWVGs) are named according to flow facing surface. Curvature of winglet mainly depends on arc angle, radius of curvature, arc length and chord length. Present study investigates the influence of arc angle variation of curved RWVG on flow and thermal characteristics for fixed chord length. Arc length and radius of curvature of curved RWVG vary according to arc angle. With the help of streaklines plots and iso-Q surfaces, flow behavior around the curved RWVG has been investigated. Heat transfer enhancement of curved RWVGs has been examined by using the dimensionless parameters surface-averaged Nusselt number, while pressure loss is estimated by friction factor. The overall thermohydraulic performance of curved RWVGs is inspected by thermal performance factor. Investigations of secondary flow intensity are carried out to understand its impact on heat transfer mechanism. From the investigation of secondary flow, it is observed that secondary flow provides a supplement to the traditional method of analyzing heat transfer performance. [ABSTRACT FROM AUTHOR]