Regular Article

Thermohydraulic characteristics and entropy analysis of a novel clockwise and anti-clockwise twisted sinusoidal wavy micro-channel under pulsating inlet condition^★

¹ Center for Renewable Energy and Environment Development, Department of Mechanical Engineering, Birla Institute of Technology and Science, Pilani, Pilani Campus, VidyaVihar, Rajasthan 333 031, India
² Department of Mechanical Engineering, Jadavpur University, Kolkata 700 032, West Bengal, India

^* e-mail: suvanjan.bhattacharyya@pilani.bits-pilani.ac.in

Received: 9 June 2020
Received in final form: 10 September 2020
Accepted: 5 October 2020
Published online: 20 November 2020

Abstract

Heat transfer performance of microchannel are becoming an important area of research with the current fast growing scenario of high speed computing and miniaturized electronic devices. These devices pile up large amount of heat accompanied by smaller surface area to release it. The current work examines unsteady, laminar flow heat transfer inside a novel twisted sinusoidal wavy microchannel. The channel with square cross section is wavy in nature as well as twisted. The first half portion of the channel is twisted clockwise, whereas the twist in the remaining part is having counterclockwise twist. The novel geometry promotes mixing of fluid layers leading to transport augmentation. The inlet pulsation follows sinusoidal pattern in time. The thermal performance parameter of the proposed novel geometry was assessed within a Reynolds number range of 1–100. Both the pulsation amplitude and Strouhal number are varied during the course of this study. To solve the governing equations, a finite volume based method was utilized. The Nusselt number data shows significant enhancement for the sinusoidal inlet velocity as compared to that of the steady case, i.e. without inlet flow pulsation. The performance enhancement criterion combining heat transfer and pressure drop shows significant improvement over steady flow case as well as for one-way twisted tube. Entropy generation, which is the measure of dissipated energy, is also reported in the present work.