Empirical correlation of laminar forced convective flow in trapezoidal microchannel based on experimental and 3D numerical study

In this paper, the fluid flow and heat transfer characterizations in trapezoid shaped microchannel with H1 (axially constant heat flux and circumferentially constant temperature) and H2 (constant axial and circumferential wall heat flux) boundary conditions are studied. A three-dimensional numerical model is developed for trapezoidal geometries with side-angles of 30° and 60° with different aspect ratios ranging from 0.1 to 10 to evaluate the Nusselt number and Poiseuille number for fully-developed and developing flow conditions. Experiments are performed on a trapezoidal microchannel and experimental results are compared with the three-dimensional conjugate heat transfer numerical model. It is found that the experimental results are close to the H1 boundary condition. The Nusselt number and Poiseuille number are found to be increasing with the side-angle and aspect ratio of trapezoidal channel. Generalized correlations for Poiseuille number, Nusselt number and entrance length are developed for trapezoidal channel with side angles in the range of 30°–60° and aspect ratios of 0.1–10. These correlations can be used for designing of trapezoidal microchannel in future heat transfer applications.