Hydrodynamic Stimuli and Hydrodynamic Noise

Comprehensive characteristics of a pneumatic underwater launching system were analyzed and the simulation was carried out by simulink. The components of the pneumatic underwater launching system were introduced, and the theoretical calculation formula for the system was derived. A rated pressure of 3.5MPa and 5MPa was offered in the numerical work. Analyses in different piston height show good behaviors: Proper increase of piston-initial accumulator pressure is beneficial to reduce hydrodynamic noise, choose the appropriate pressure of accumulator. The hydrodynamic noise of the system can be significantly reduced by optimizing the structure of the double-acting cylinder, increasing the height of the piston and improving the structure of the piston.

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Sensitivity of Central Units in the Goldfish, Carassius auratus, to Transient Hydrodynamic Stimuli (Part 2 of 2)

Brain Behavior and Evolution ◽

10.1159/000316298 ◽

1997 ◽

Vol 50 (5) ◽

pp. 273-283

Author(s):

Joachim Mogdans ◽

Horst Bleckmann ◽

Nicole Menger

Keyword(s):

Carassius Auratus ◽

Hydrodynamic Stimuli

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Hydrodynamic Noise and Radiated Mechanism of 3D Cavity

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.217-219.2590 ◽

2012 ◽

Vol 217-219 ◽

pp. 2590-2593 ◽

Cited By ~ 1

Author(s):

Yu Wang ◽

Bai Zhou Li

Keyword(s):

Sound Pressure ◽

Near Field ◽

Low Frequency ◽

Dipole Source ◽

Fluctuating Pressure ◽

Common Structure ◽

Hydrodynamic Noise ◽

Near Field Sound ◽

Equivalent Sources ◽

Field Sound

The flow past 3D rigid cavity is a common structure on the surface of the underwater vehicle. The hydrodynamic noise generated by the structure has attracted considerable attention in recent years. Based on LES-Lighthill equivalent sources method, a 3D cavity is analyzed in this paper, when the Mach number is 0.0048. The hydrodynamic noise and the radiated mechanism of 3D cavity are investigated from the correlation between fluctuating pressure and frequency, the near-field sound pressure intensity, and the propagation directivity. It is found that the hydrodynamic noise is supported by the low frequency range, and fluctuating pressure of the trailing-edge is the largest, which is the main dipole source.

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