Cavitation Prediction in Liquid Ring Pump for Aircraft Fuel Systems by CFD Approach

Liquid ring pumps are used in aircraft fuel systems in conjunction with main impeller pumps. These pumps are used for priming the pump system as well as to remove fuel vapor and air from the fuel. Prediction of cavitation in liquid ring pumps is important as cavitation degrades the performance of these pumps and leads to their failure. As test based assessment of cavitation risk in liquid ring pump is expensive and time consuming, recent approaches have been to assess and predict the risk of cavitation using Computational Fluid Dynamics (CFD) methods with the goal to quicken the design process and optimize the performance of these pumps.

The present study deals with the development and assessment of a CFD methodology to simulate cavitation for a liquid fuel pump used in aircraft fuel systems. The study simulates the cavitation phenomena using a multi-phase flow model consisting of fuel vapor, air, and liquid fuel phases. The rotation of the blades is simulated using two approaches, a steady state multiple reference frame approach and a transient sliding mesh approach. The results demonstrate that the numerical model employing transient sliding mesh approach along with a standard k-e turbulence model, although computationally expensive, is required to predict the cavitation phenomenon in liquid ring pumps accurately.