The vena contracta coefficient of an orifice flow excited by high-intensity sound wave

Constant value of vena contracta coefficient has been commonly used in the quasi-steady models for computing the nonlinear acoustic impedance of an orifice. However, this assumption degrades the accuracy of the theoretical models. In this paper, the relation between the vena contracta coefficient and the sound intensity is quantitatively established by combining a discrete vortex method and a quasi-steady model for the nonlinear acoustic phenomenon, which shows good agreement with the previous experiment. It is demonstrated that, by the use of the proposed vena contracta coefficient-sound intensity curve, the quasi-steady model can accurately and efficiently predict the nonlinear acoustic impedance, thus being well suitable for engineering applications.