Unsteady Flow and Heat Transfer in a Plate-Fin and Tube Heat Exchanger

Abstract

Fluid flow and heat transfer in a plate-fin and tube heat exchanger were studied, using a fundamental model consisting of a pair of parallel plates and a square cylinder passing perpendicularly through the plates, which simulated plate-fins and a tube, respectively. The analytical results are reported about the unsteady flow and heat transfer at the Reynolds number Re=1 000 and the Prandtl number Pr=0.71. The unsteady flow around a cylinder is shown in terms of time histories, velocity flucutuation intensity conoturs and the Strouhal numbers. Complicated aspects of the fluid flow are shown in terms of velocity vectors, streamlines, streak lines, pressure contours and wall shear stress contours. Furthermore, heat transfer characteristics under a constant wall heat flux condition are shown in terms of distributions of temperatures and local Nusselt numbers, and the mechanisms of fluid flow and heat transfer are systemtically examined in detail.