Numerical determination of heat transfer and pressure drop characteristics for a converging-diverging flow channel

A finite difference scheme was utilized to predict periodic fully developed heat transfer and fluid flow characteristics in a converging-diverging flow channel. The basis of the method is an algebraic nonorthogonal coordinate transformation which maps the complex fluid domain onto a rectangle. This transformation avoids the task of numerically generating boundary-fitted coordinates. The transformed equations and the entire discretization procedure were documented in an earlier paper which dealt with a general class of nonperiodic problems. Its adaptation to a periodic sample problem of converging-diverging flow channel will be illustrated in this work. Representative results were carried out for laminar flow, Prandtl number of 0.7, in the Reynolds number range from 90 to 1635, for various taper angles of converging-diverging flow channel, and for three ratios of maximum/minimum height of the flow channel. Moderate enhancement in the Nusselt number results occurred, at higher values of Reynolds number for most cases, when compared with corresponding values for straight ducts. © 1987 by ASME