渦糸近似法における非定常圧力および力の計算

抄録

This paper presents a method for calculation of the unsteady force, the moment, and the pressure distribution on the body in a two dimensional flow using the discrete vortex method. The body surface is represented by discretized point vorteces, and the force and the moment are obtained by integrating the pressure along the body surface. A mathematical formulation is presented for a flat plate, and this is extended to arbitrary shaped bodies (a square cylinder as an example). The pressure distribution is obtained by estimating the argument of the logarithmic singularities. This method is direct in its derivation and applicable to the cases for which the so-called generalized Blasius theorem or the control volume method are difficult to be used. It is also shown that the force obtained by the present method and that by the above mentioned two methods have some difference. This difference is considered to be caused by the mathematical incompleteness of the discrete vortex method.