A 3D Computational Fluid Dynamics and Acoustics Simulation Approach for Noise Mitigation Prediction in Gerotor Pumps

Abstract

<div class="section abstract"><div class="htmlview paragraph">Positive displacement pumps are key components in automotive and hydraulic fluid systems, often serving as the primary power source and a major source of noise in both on-highway and off-highway vehicles. Specifically, gerotor pumps are widely utilized in vehicle coolant, lubricating, and other fluid systems for both conventional and electric powertrains. This study introduces a novel method for predicting noise in gerotor pumps by combining a Computational Acoustics (CA) approach with a 3D Computational Fluid Dynamics (CFD) approach, both implemented in the Simerics–MP+ code. The CFD simulation includes the detailed transient motion of the rotors (including related mesh motion) and models the intricate cavitation/air release phenomena at varying pump speeds. The acoustic simulation employs a Ffowcs–Williams Hawkings (FW–H) integral formulation to predict sound generation and propagation based on the detailed flow field predictions from the CFD model.</div><div class="htmlview paragraph">Simulations of two different gerotor pump designs were conducted under a wide range of operating conditions, resulting in the prediction of a full range of sound pressure spectra across various sound frequencies. These simulation results are compared with sound pressure measurements, revealing that the simulation approach can effectively predict the relative sound pressure distribution across the frequency spectrum. Notably, the mitigation of sound pressure at specific regions of the frequency–RPM spectrum was accurately captured. This paper provides a comprehensive insight into the modeling methodology, the experimental measurement methods, and compares the sound pressure spectra obtained from simulations and experiments. This proposed method harnesses the ability to obtain detailed, high–fidelity 3D flow field and cavitation/air release solutions in positive displacement machines and demonstrates excellent potential for predicting noise improvements resulting from pump design changes. Thus, it offers valuable insights for designing quieter pumps.</div></div>