UNSTEADY AERODYNAMIC FLOW PHENOMENA IN A TRANSONIC COMPRESSOR STAGE

A three-dimensional unsteady, viscous aerodynamic analysis has been de veloped for the flow inside a transonic, high-through-flow, single-sta ge compressor. The compressor stage is comprised of a low-aspect ratio rotor and a closely coupled stator. The analysis is based on a numeri cal method for solving the three-dimensional Navier-Stokes equation fo r unsteady viscous flow through multiple turbomachinery blade rows. Th e method solves the fully three-dimensional Navier-Stokes equation wit h an implicit scheme. A two-equation turbulence model with a low Reyno lds number modification is applied for the turbulence closure. A third -order accurate upwinding scheme is used to approximate convection ter ms, whereas a second-order-accurate central difference scheme is used for the discretization of the viscous terms. A second-order accurate s cheme is employed for the temporal discretization. The numerical metho d is applied to study the unsteady flowfield inside a transonic, high- through-flow, axial compressor stage. The numerical results are compar ed with available experimental data.