Investigation of a Cylindrical Nonacoustic-Wavenumber Calibration Array
Abstract
This thesis describes an investigation of a Cylindrical Wavenumber Calibrator (CWC). The CWC is a water-filled device designed to generate nonacoustic-wavenumber pressure fields propagating axially in the water within the calibrator. It can therefore be used to simulate the effects of flow noise on a device placed in the water. The investigation begins with the mathematical analysis of the pressure field inside an infinitely-long, liquid-filled, cylindrical chamber with an axially symmetric, normal-velocity distribution on the wall of the chamber. The analysis then continues with the study of the propagation speed in the fluid inside an infinite-length elastic tube surrounded by another fluid. A finite-length CWC is then investigated with several computer models of the CWC using the CHIEF acoustic radiation program and the ATILA finite element program. These models are integrated into a computer program that uses the electroacoustic transfer matrix for the system to compute electrical band drives designed to produce the desired nonacoustic-wavenumber fields within the CWC. A prototype CWC with 40 independently-driven bands was constructed from a piezoelectric-PVDF tube. Measured results show that relatively uniform nonacoustic wavenumber pressure fields can be created with the CWC.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 15, 1993
- Accession Number
- ADA274929
Entities
People
- L. D. Luker
Organizations
- United States Naval Research Laboratory