Finite-Difference Implementation of Inviscid Separated Flows with Infinitely-Long Cusp-Ended Stagnation Zone around Circular Cylinder

摘要

The classical Helmholtz problem is applied for modelling and numericalinvestigation of inviscid cusp-ended separated flow around circular cylinder.Two coordinate systems are used: polar for initial calculations and parabolicas topologically most suited for infinite stagnation zone. Scaling by the shapeof the unknown free line renders the problem to computational domain with fixedboundaries. Difference schemes and algorithm for Laplace equation and forBernoulli integral are devised. A separated flow with drag coefficient $C_x=0$like the so called ``critical'' flow is obtained. The pressure distribution onthe surface of cylinder and the detachment point compares quantitatively verywell with the predictions of the hodograph method.