Abstract
Three-dimensional laminar flows in various curved pipes(i.e., Rc/a=2, 4, 7 and 9 for curved 180 degree pipes and Rc/a=2 and 4 for curved 90 degree pipes) were numerically simulated by using time-dependent incompressible Navier-Stokes equations. The boundary-fitted coordinate system was used in order to treat the complicated boundary configurations of strongly curved pipes. The obtained flow patterns and the magnitude of the secondary flow in case of Rc/a=9 for curved 180 degree pipe were in good agreement with the experimental results. The ellipticity of the basic equation was very important to simulate these recirculating flows, especially when the curvature ratio was small. Velocity and pressure fields were visualized by a pseudo-color technique on a workstation.
