Session: 01-08-01: Passive, Semi-Active, and Active Noise and Vibration Control

Paper Number: 166673

Noise Mitigation Analysis in Relief Valves Using a Hybrid CFD-Acoustics Approach 

Hydrostatic axial piston pumps play a pivotal role in industries such as construction, forestry, and crane operations, where they are valued for their high efficiency and ability to transfer significant amounts of power. However, their optimization, especially in terms of noise reduction, poses significant engineering challenges. Noise is particularly problematic at low engine speeds, where the absence of ambient noise to mask acoustic emissions can make undesirable sounds more perceptible. One of the key contributors to this noise is the relief valve, where turbulent fluid flow, cavitation, and high-speed jets combine to elevate noise levels and compromise system performance. The effects of these noise-generating mechanisms extend beyond just acoustics, influencing the operational efficiency and longevity of the pump system. In this study, we delve into the underlying causes of noise generation in relief valves operating under high-pressure reduction ratios using computational simulations. The adopted approach integrates Wall-Modeled Large Eddy Simulation (WMLES) with the Ffowcs Williams and Hawkings (FWH) acoustic analogy, all executed within a second-order finite volume framework using the Simerics-MP+ platform. This hybrid methodology allows for highly accurate resolution of both large-scale turbulent structures and near-wall dynamics, and it also enables the prediction of far-field acoustic behavior by effectively capturing surface pressure fluctuations that contribute to the emitted sound.

The results from the simulations reveal several critical mechanisms behind the noise generation within the relief valve. High-speed jets, which form between the poppet and the valve seat, lead to rapid pressure fluctuations and the formation of turbulent wakes. These turbulent structures contribute to the increase in sound emissions. Flow impingement on the valve’s outer walls further amplifies the acoustic output. Notably, oscillatory behavior was observed at lower flow rates (10 and 11 LPM), which resulted in more pronounced tonal noise components compared to higher flow rates, such as 19 LPM. The study also demonstrated the reasonable prediction of cavitation phenomena within the relief valve, which, while not the primary noise source, does contribute to the overall acoustic signature of the system. Importantly, the computational framework showed a strong correlation with experimental data, validating the hybrid WMLES-FWH approach’s ability to accurately capture both the complex flow dynamics and the resulting acoustic emissions. By combining high-fidelity turbulence modeling with FWH acoustic analysis, this research offers valuable insights into the intricate interactions responsible for noise generation in relief valves. The findings will contribute to ongoing efforts aimed at improving noise mitigation strategies for axial piston pumps, enhancing their overall efficiency, reliability, and operator comfort, while also providing critical data for the development of quieter, more durable pump systems in industrial applications.

Presenting Author: Salar Taghizadeh Simerics Inc.

Presenting Author Biography: Dr. Salar Taghizadeh holds a PhD in Mechanical Engineering from Texas A&M University, with a focus on turbulent fluid flow, heat transfer, and the optimization of thermo-fluid systems. He has expertise in Computational Fluid Dynamics (CFD) and Machine Learning (ML), applying these skills to enhance system performance. Since joining Simerics Inc. in 2023, Dr. Taghizadeh has been involved in solving a range of engineering problems, utilizing his CFD expertise to improve designs and system efficiency. His work is centered around the integration of advanced simulation techniques to address real-world fluid dynamics and thermal management challenges.

Authors:

Salar Taghizadeh Simerics Inc.
Jan Oravec Danfoss Power Solutions a.s.
Sujan Dhar Simerics Inc.