STRUCTURE OF VELOCITY AND TEMPERATURE FIELDS IN LAMINAR CHANNEL FLOWS WITH LONGITUDINAL VORTEX GENERATORS

Abstract

Laminar velocity and temperature fields in a rectangular channel with a row of built-in vortex generators in the form of slender delta wings and winglet pairs have been calculated by means of a ifinal method consisting of zones of complete and partially parabolized Navier-Stokes and energy equations. A modified version of SOLA for incompressible as well as for variable-density, small-Mach number flows has been used to solve the basic equations. Each wing or winglet pair generates counterrotating longitudinal vortices that, in contrast to similar vortices in an unbounded medium, show an elliptic deformation, a wakelike axial velocity distribution in the core, and an absence of breakdown even at angles of attack as large as 50° The spiraling motion induced by these vortices in the channel can locally enhance the heat transfer coefficient by a factor of 3 compared to its value in a wingless channel. The temperature dependence of density can reduce this enchancement by roughly 10% when the ratio of gas-to-wall temperature is 1.3