Experimental study on the wall-pressure fluctuations of flow over an axisymmetric hull

TL;DR

This paper presents the first high-fidelity experimental database of wall-pressure fluctuations on an axisymmetric hull at high Reynolds numbers, including complex maneuvering conditions, to improve understanding and modeling of flow noise for underwater vehicles.

Contribution

It provides a comprehensive experimental dataset under realistic conditions, revealing Reynolds number effects and pressure-gradient influences on turbulent flow noise.

Findings

Reynolds number effects cause a spectral energy shift to lower frequencies.

Pressure-gradient effects significantly influence spectral scaling laws.

The dataset serves as a benchmark for validating flow noise prediction models.

Abstract

Wall pressure fluctuations beneath the turbulent boundary layer of high-speed underwater vehicles are crucial for hydro-acoustics and acoustic stealth. However, a comprehensive understanding remains limited due to a lack of high-quality experimental data, particularly under realistic operational conditions. To address this gap, this study establishes the first high-fidelity experimental database of wall-pressure fluctuations on an axisymmetric hull at high Reynolds numbers. The dataset's primary innovation is its systematic inclusion of complex maneuvering (yaw and pitch) conditions, providing a benchmark for validating flow noise prediction models. Analysis of this dataset yields key physical insights. The study quantifies systematic Reynolds number effects, including a spectral energy shift toward lower frequencies, and spectral scaling laws by revealing the critical influence of pressure-gradient effects. These findings provide fundamental insights into non-equilibrium 3D turbulent flows and establish an essential dataset to support the design of quieter and more effective underwater vehicles.