FULLY DEVELOPED TURBULENT FLOW IN ISOSCELES TRIANGULAR DUCTS

Abstract

Fully developed turbulent flow through isosceles triangular ducts was investigated over a Reynolds number range of 5000 to 50, 000. The apex angle was varied from 5.7° to 60°. For flow prediction, the vorticity production terms were expressed by modelling the Reynolds stress in terms of the mean axial velocity gradients and a geometrically calculated turbulence length scale. The predicted results of velocity distribution and wall shear stress distribution are in good agreement with the experimental results in the literature except very near the apex. The secondary flow pattern over a wide range of apex angle was predicted. Maximum secondary velocity was less than 2% of the bulk velocity.