Numerical Prediction of Multi-Stage Axial Flow Compressor off-Design Performances

The paper presents numerical predictions of design and off-design performance for multistage axial compressors.A time marching,implicit,finite-difference scheme was used to solve three-dimensional Reynolds-averaged Navier-Stokes equations.The shocks in transonic flow field are captured with a high resolution procedure.The turbulent viscosity is calculated using the two-layer Baldwin-Lomax algebraic turbulence model.Detailed computations were carried out for a five stage high-pressure compressor configuration for design and off-design conditions at 100%,90% and 80% corrected speeds.The mass flow rate convergences were obtained (smaller than 1%) at all these computations.The predicted results of stage and multistage performances at design operating point show a good agreement with the design.The surge margin at design operating point was estimated by the numerical results.The Maximum difference of stator blade inlet flow angles between design and off-design operating points is larger than 15 degrees at design speed.