Author(s)

P. Prinos & J. Rasoul

Abstract

Turbulent flow in an open channel with a backward-step P. Prinos, J. Rasoul Hydraulics Lab., Department of Civil Eng., Univ. of Thessaloniki, Thessaloniki, Greece ABSTRACT The backward-step flow in an open channel is studied numerically using a finite volume method for solving the Reynolds averaged Navier-Stokes equations in conjuction with turbulence models of the k-s type. The standard k-s model of turbulence and a model of the same type, based on the RNG approach of Yakhot and Orszag (22), are used and computed results are compared against experimental measurements of Nakagawa and Nezu (13). The latter model is found to perform better than the standard k-s model especially in the recirculation region behind the step. Reattachment length, velocity, turbulence kinetic energy and shear stress are predicted better by this model. The standard k-s model substantially underpredicts the experimental reattachment length ( up to 19%) while the RNG k-s model is

Keywords