Thursday, October 24, 1985 3:30 p.m.
Mark F. Hamilton and James A. TenCate
Department of Mechanical Engineering
The University of Texas at Austin
The noncollinear interaction in a rectangular duct of finite amplitude sound waves propagating in higher order modes is investigated both theoretically and experimentally. The theory predicts spatial oscillations in the nonlinearly generated sound field due to dispersion, and a coefficient of nonlinearity that depends on the angle at which the interacting waves intersect. Experimental results are reported for the interaction of waves in the (0,0) and (1,0) modes in an airfilled rectangular duct. Alternative formulations of the wave equation will be used to demonstrate the importance of imposing the proper boundary condition at the source.