Yt. Yang et Cl. Kuo, NUMERICAL STUDY OF A BACKWARD-FACING STEP WITH UNIFORM NORMAL MASS BLEED, International journal of heat and mass transfer, 40(7), 1997, pp. 1677-1686
This study presents the numerical predictions of the fluid flow charac
teristics within the recirculation zone for a backward-facing step wit
h uniform normal mass bleed. The turbulent governing equations are sol
ved by a control-volume-based finite-difference method with power-law
scheme. A new turbulence model is proposed to describe the turbulent s
tructure. Non-uniform staggered grids are used. The parameters studied
include entrance Reynolds number (Re), and the velocity of the normal
mass bleed (V-s). The channel expansion ratio ER = 1.3, and the worki
ng medium is air. The numerical results show the uniform normal mass b
leed suppresses the reverse horizontal velocity, turbulence intensity,
and Reynolds shear stress within the recirculation zone. The attachme
nt point extends to downstream. Better computational predictions are o
btained with the new turbulence model by the introduction of the Kolmo
gorov velocity scale, U-epsilon = (nu epsilon)(1/4) instead of frictio
n velocity U-tau . Copyright (C) 1996 Elsevier Science Ltd.