ACOUSTIC ATTENUATION PERFORMANCE OF CIRCULAR FLOW-REVERSING CHAMBERS

A three-dimensional analytical approach is developed to determine the transmission loss of circular flow-reversing chambers in the absence o f bulk flow. The study couples the continuity conditions of the acoust ic pressure and particle velocity at the inlet and outlet with the ort hogonality relations of Fourier-Bessel functions. The present analytic al results are compared with the boundary element predictions to asses s the approach, as well as with previous works to examine the effect o f nonplanar wave decay in end ducts. The acoustic attenuation due to f low-reversing chamber is then investigated in detail as a function of the length-to-diameter ratio of the chamber and the relative locations of the inlet/outlet. (C) 1998 Acoustical Society of America. [S0001-4 966(98)01711-1]