Accession Number : AD1034376

Title :   Underwater Acoustic Carbon Nanotube Thermophone

Descriptive Note : Technical Report

Corporate Author : Naval Undersea Warfare Center Newport United States

Personal Author(s) : Howarth,Thomas R ; Huang,Dehua

Full Text :

Report Date : 23 Sep 2016

Pagination or Media Count : 10

Abstract : The present invention is an acoustically transparent carbon nanotube underwater acoustic source which acts as a thermophone based on an energy conversion of heat to sound. The principle of thermal acoustic transduction is thatwhen alternating current is passed through a comparatively thin transducer; periodic heating takes place in the conductor following variations in current strength. This periodic heating produces temperature waves which propagate into a surrounding medium. The amplitude of the temperature wave decreases rapidly as the distance from the conductor increases. Based on the rapid production of these temperature waves; the net effect is to produce a periodic rise in temperature in a limited portion of the medium near the conductor. Thermal expansion and contraction of this layer of the medium determines the amplitude of the resulting sound waves.

Descriptors :   carbon nanotubes , underwater acoustics , transducers , acoustic propagation , sound waves

Subject Categories : Acoustics
      Refractory Fibers

Distribution Statement : APPROVED FOR PUBLIC RELEASE