DISTORTED PRESSURE HISTORIES DUE TO THE STEP RESPONSES IN A LINEAR TAPERED PIPE. (6th REPORT, FOR ARBITRARY CROSS SECTIONS).

A new method of solving a one-dimensional wave equation in linear tapered compound pipes with arbitrary cross-sections has been devised. Results obtained by this theory are compared with experiments in pipes with square cross-sections. And we obtained the following conclusions: (1) Damping coefficients in an arbitrary cross-section are defined and are expressed analytically for some representative cross-sections. (2) The viscous solution of a wave equation obtained by Laplace transform explains well distorted pressure histories in a linear tapered pipe with an arbitrary cross-section. (3) Pressure waves in a square cross-section include higher modes of frequency and damp more rapidly than those in a circular cross-section.