Abstract: A two equation turbulence mode of K ε type was recently derived by Yakhot and Orszag on Renormalization Group (RNG) methods.It was applied to solve the turbulent separated flows in a 180 deg duct.The scheme has been developed for a generalized coordinate system and in based on a control volume approach with a staggered grid arragement.The physical covariant velicity components are selected as the dependent variable in the momentum equations.The detail numerical results were given and compared with th...