Numerical simulation of the performance of axial compressors using a multistage CFD code

摘要

A 3D numerical simulation code FLFD was developed, which is a standard three-dimensional viscous flow solver in a multistage axial compressor. The k-ε turbulence model was implemented and the source terms in k-ε turbulence model were treated implicitly to relieve the stiffness of k-ε equations. A staggered finite volume method was used to make the mean flow equations and turbulence model equations strongly coupled and enhance the stability of the numerical computation. A steady state solution was obtained using five-stage Runge-Kutta time-stepping scheme with local time stepping and residual smoothing to accelerate convergence. A mixing plane was set to communicate between the adjacent blade rows. Four methods of dealing with the mixing plane were discussed and their respective features were analyzed. The code was first verified against a single-stage fan with compared with the commercial software. Further validation was conducted on a four-stage fan. Numerical simulation of the overall performance for a multistage fan was carried out with the CFD code developed for the engine matching and for validating the code reliability and accuracy. By analyzing the results, predictions show good agreement with test data, but the shortcoming causing by the mixing plane needs to be improved.