Expansions for the radiation impedance of a rectangular piston in an infinite baffle

Relatively compact analytical expressions in the form of fast-converging expansions are derived for the radiation resistance and reactance of a rectangular rigid piston in an infinite rigid baffle, which are computationally efficient at high frequencies or large aspect ratios and yield simple approximations ( asymptotic expressions) at low frequencies. Plots of the normalized radiation resistance and reactance are shown for various aspect ratios with constant width as well as constant area. Comparisons are also made with the impedance of an elliptic piston. (C) 2016 Acoustical Society of America.