Numerical study of a backward-facing step with uniform normal mass bleed

✍ Scribed by Yue-Tzu Yang; Chung-Lun Kuo

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 602 KB
• Volume: 40
• Category: Article
• ISSN: 0017-9310
• DOI: 10.1016/s0017-9310(96)00219-0

✦ Synopsis

This study presents the numerical predictions of the fluid flow characteristics within the recirculation zone for a backward-facing step with uniform normal mass bleed. The turbulent governing equations are solved by a control-volume-based finite-difference method with power-law scheme. A new turbulence model is proposed to describe the turbulent structure. Non-uniform staggered grids are used. The parametels studied include entrance Reynolds number (Re), and the velocity of the normal mass bleed (Vs). The channel expansion ratio ER = 1.3, and the working medium is air. The numerical results show the uniform normal mass bleed suppresses the reverse horizontal velocity, turbulence intensity, and Reynolds shear stress within the recirculation zone. The attachment point extends to downstream. Better computational predictions are obtained with the new turbulence model by the introduction of the Kolmogorov velocity scale, U, = (w)L/4 instead of friction velocity U,.