MODELING OF THE SEAT DIP EFFECT USING THE FINITE-DIFFERENCE TIME-DOMAIM METHOD

In this paper the use of the finite-difference time-domain technique f or the modeling of the seat dip effect in concert halls is demonstrate d. The linear time-domain acoustic partial differential equations are discretized using a finite-difference technique. The second-order accu rate differencing scheme is time-space centered, and the velocity and pressure are solved on an interlaced mesh. First- and second-order Mur absorbing boundary conditions, originally formulated for electromagne tic problems, are adapted to the acoustics case and used to truncate t he numerical grid. The technique is first verified by comparing the nu merical results to the analytic solution of a simple point source. Res ults from computer simulations of the seat dip phenomena are compared with the findings of previous studies where measurements had been made on scale models and in real concert halls. The computer model success fully predicts the effects associated with the source-receiver distanc e, the height of the receiver, and the height of the source. (C) 1996 Acoustical Society of America.