Heat transfer and fluid flow over microscale backward and forward facing step: A review

Abstract

Research on convective heat transfer in the microscale backward-facing step (MBFS) and microscale forward-facing step (MFFS) has been extensively conducted in the past decade. This review summarizes numerous researches on the three topics; the first section focuses on studying the effect of the geometry on the fluid flow and heat transfer behavior. The second and the third section concentrates on effect the inclination angle and the flow regime on the fluid flow and heat transfer enhancement. The purpose of this article is to get a clear view and detailed summary of the influence of several parameters such as the geometrical specifications, type of fluids and boundary conditions. The enhancement in the Nusselt number is the main target of such research where correlation equations were developed in numerical and experimental studies are reported.

Assessment of vortex generator shapes and pin fin perforations for enhancing water-based heat sink performance

“…The enhancement of heat transfer and fluid flow characteristics were investigated experimentally in 1969 [23]. VGs can take various forms such as protrusions, wings, inclined blocks, winglets, fins, and ribs [24,25], and have been used to enhance heat transfer in different geometries such as circular and non-circular ducts under turbulent flow [26][27][28][29]. They have also been used in laminar flow [24,[30][31][32][33] which is effective to enhance the heat transfer rate, with flat plate-fins in rectangular channels [34][35][36], tube heat exchangers [17,37], heat sinks [30,38] and rectangular narrow channels [32,39].…”

A practical evaluation of the performance of Al2O3-water, TiO2-water and CuO-water nanofluids for convective cooling

“…Nanofluids have proved beneficial in a wide range of applications, such as in the chemical, electrical and nuclear industries, in cancer diagnosis, solar energy capture, high-powered lasers, drilling and in enhanced oil recovery [1][2][3][4]. They have also been widely promoted for heat transfer applications, where it has been claimed that they can offer significantly enhanced heat transfer [5][6][7], while alleviating the problems of clogging, erosion and sedimentation associated with suspensions that contain larger particles [8].…”

Free-molecular and near-free-molecular gas flows over backward facing steps

“…In line with the above set of works, the channel flow over microscale steps has been investigated and recently reviewed (Kherbeet et al 2016). Focusing on the limit of small Knudsen (Kn) numbers, several studies have applied continuum-limit models to describe and monitor the detachment and reattachment phenomena in a slightly rarefied gas (Beskok 2001;Baysal, Erbas & Koklu 2004;Bao & Lin 2011).…”