Numerical Investigation on Compressible Flow Characteristics in Axial Compressors Using a Multi Block Finite Volume Scheme

Abstract

An unsteady two-dimensional numerical investigation was performed on the viscous flow passing through a multi-blade cascade. A Cartesian finite-volume approach was employed and it was linked to Van-Leer's and Roe's flux splitting schemes to evaluate inviscid flux terms. To prevent the oscillatory behavior of numerical results and to increase the accuracy, Monotonic Upstream Scheme for Conservation Laws (MUSCL) was added to flux splitting schemes. The Baldwin-Lomax (BL) turbulence model was implemented to solve the turbulent case studies. Implicit solution was also provided using Lower and Upper (LU) decomposition technique to compare with explicit solutions. To validate the numerical procedure, two test cases are prepared and flow over a NACA0012 airfoil was investigated and the pressure coefficients were compared to the reference data. The numerical solver was implemented to study the flow passing over a compressor cascade. The results of various combinations of splitting schemes and the MUSCL limiter were compared with each other to find the suitable methods in cascade problems. Finally, the convergence histories of implemented schemes were compared to each other to show the behavior of the solver in using various methods before implementation of them in flow instability studies.