PREDICTION OF THE VIBROACOUSTIC TRANSMISSION LOSS OF PLANAR HOSE-PIPESYSTEMS

Vibro-acoustic energy travels through hose walls as longitudinal waves and flexural waves, apart from the sound waves through the fluid medi um inside. Longitudinal waves in the hose wail are coupled to the soun d waves inside by means of the hose-wall Poisson's ratio. Both in turn get coupled to bending or flexural waves because of the energy transf er or interaction at the bends. For any of these three types of waves incident on one end of a hose, waves of all the three types may be tra nsmitted on the other end because of their dynamical coupling with one another. Therefore, in the present paper, expressions have been deriv ed for the 3x3 transmission loss matrix for a two-dimensional or plana r piping system in terms of elements of the overall 8x8 transfer matri x of the system. These expressions have then been used in a comprehens ive computer program to evaluate the vibro-acoustic performance of hos es, with particular application to the automotive climate control syst ems with gaseous as well as liquid media. Finally, parametric studies have been made that have led to some general design guidelines. (C) 19 97 Acoustical Society of America.