The primary function of an aero engine fuel system is to supply metered fuel to the combustion chamber at all operating conditions based on the flow demand set by the engine controller. Centrifugal pump is one of the components in fuel system that feeds fuel to the HP pump. Impeller design is a critical one which dictates the overall performance of centrifugal pump. This paper discusses about design and performance evaluation of impeller with twisted blade configuration. Impeller design is performed based on Euler’s one dimensional theory.
Steady state performance of the impeller at design and off-design operating conditions is analyzed by using commercial CFD code ANSYS-CFX with a standard SST turbulence model. The governing mathematical model for flow analysis is a three dimensional incompressible Reynolds Averaged Navier-Stokes (RANS) equation. Cavitation phenomenon is simulated in the CFD multiphase analysis to assess the pump impeller performance under cavitation at different NPSH values. Rayleigh-Plesset cavitation model is used along with RANS equation to perform cavitation analysis.
From this study, the simulation method and technique adapted is appropriate for predicting the performance of impeller of centrifugal pump with or without cavitation. Performance of the impeller reduces drastically as there is decrease in NPSH. The prediction of critical NPSH is vital for safer operation of the pump, specifically at high altitude the pump inlet pressure falls which may result in cavitation during operation.