Directed sound generator - directed mass flow modulated in fluid medium at defined speed and acts as acoustic volume source and also as acoustic force density source

摘要

A directed mass flow(m) is modulated in a fluid medium at a defined speed(v), and by reason of the time change of the volume flow produced by it acts on the one hand as an acoustic volume source, and on the other hand, by reason of its time variable impulse flow(m.v) acting on the fluid in the outflow direction, acts as an acoustic force density source, and by superimposition of the two sound pressure portions a directed sound radiation at low frequency is achieved.