The SIMPLE Algorithm With Hight-order Schemes And Its Application In Turbomachines

The internal turbulent flow of turbomachinery is an extremely complex problem. It's accurate prediction has always been one of the most important tasks for CFD research. In this paper, the problem relevant to the so-called false diffusion in predicting the "jet-wake" structure in centrifugal impeller is analyzed numerically by using high resolution alogorithm and the RNG k-ωmodel.The accuracy of the algorithm is the basic issue of concern for numerical simulation. In this paper, some high accurate schemes have been used for discretisation in the nonstaggered SIMPLE code, while the deferred correction method is employed for improving the convergence.Based on these, the high-order algorithm combined with the advantage of RNG k-ωmodel in rotational flow, is used to simulate the 3D turbulent flow in the well known centrifugal Ghost impeller. The turbulent flow and "jet-wake" structure in centrifugal impeller are analyzed.Numerical simulation of an axial fan to predict the flow field in a particular state is caried out. According to the distribution of pressure, velocity and streamline, vortical motion and energy loss inside the fan are discussed in detail. The optimal flow rate for the design rotation speed is found.A specific grid-reading procedure is proposed for transfering the computational mesh generated by the Cambit to our flow solver. This procedure is able to reduce the difficulty for grid generation.