擬似圧縮性解法によるフランシス水車ランナの乱流数値解析

The three-dimensional Navier-Stokes method with the pseudo-compressibility, the implicit formulation of finite difference, and the turbulence model has been developed for the Francis water runner. The viscous flow in the rotating field can be simulated well with the k-ε two-equation turbulence model in the design condition and several off-design conditions. The results agree with the experimental data under the design flow condition. The strong vortex is predicted near the leading edge and developed in the radial direction under the off-design conditions. Because this program employs the efficient approximate factored method as a time marching as well as the wall function near the wall for the k-ε model, it does not require large amounts of CPU time and it can be used even on a downsized computer such as a work station.