A simultaneous variable solution procedure for laminar and turbulent flowsin curved channels and bends

Direct Numerical Simulation of turbulent flow requires accurate numerical t echniques for solving the Navier-Stokes equations. Therefore, the Navier-St okes equations in general orthogonal and nonorthogonal coordinates were emp loyed and a simultaneous variable solution method was extended to solve the se general governing equations. The present numerical method can be used to accurately predict both laminar and turbulent flow in various curved chann els and bends. To demonstrate the capability of this numerical method and t o verify the method, the time-averaged Navier-Stokes equations were employe d and several turbulence models were also implemented into the numerical so lution procedure to predict flows with strong streamline curvature effects. The results from the present numerical solution procedure were compared wi th available experimental data for a 90 deg bend. All of the turbulence mod els implemented resulted in predicted velocity profiles which were in agree ment with the trends of experimental data. This indicates that the solution method is a viable numerical method for calculating complex flows. [S0098- 2202(00)01803-4].