Numerical simulation of centrifugal compressor

Design of 3D-centrifugal impeller blades is a compromise between manufacturability and aerodynamics. The aerodynamic requirement is that edge velocities along the impeller channel passage surfaces like hub, shroud, pressure and suction surfaces vary smoothly without sudden decelerations, which would otherwise cause flow separation leading to losses. The paper aims to study several flow characteristics between blade channels using commercial flow solver CFX based on finite volume techniques. From the public domain literature, using the blade data, profiles are developed, for which multiblock hexahedral computational meshes are generated. Using the periodic boundaries and defined flow conditions at inflow / exit flow and blade rotations, the turbulent viscous flow between blade channels are computed. The efficiency related parameters using average quantities, besides flow pattern in terms of velocities, streamlines and pressure distribution on blade surfaces are graphically interpreted. An attempt is also made to study the influence of pressure loads on structural deformations in the chosen blade profile. This analysis also provides insights into the locations of maximum principal stresses or equivalent stresses on blade surfaces. This paper highlights aero-mechanical features of centrifugal impeller obtained from several numerical simulations, which are expected to provide a sound basis for further investigations.