Prediction of surface normal velocity for an arbitrary acoustic source using an equivalent phased array method

The equivalent phased array method (EPAM) treats an acoustic source as a 'phased array' composed of many small elements, in order to predict acoustic fields generated by the source. In this paper, a new method of EPAM, based on solutions to the exterior steady-state acoustic radiation problem, is proposed. We attempt to apply this method, instead of near-field acoustical holography (NAH), to predict the surface normal velocity of the acoustic source. This method is applicable to the prediction of the surface normal velocity for sources that have arbitrary shapes and is therefore expected to work well for the practical experiments. The results of computer simulations using quadrapole-type sources demonstrate the validity of this method.