Numerical simulations of separated flows around bluff bodies by the discrete vortex method

Separated flows around bluff bodies are simulated numerically by the discrete vortex method combined with the panel method. The potential flows around bluff bodies are expressed by discrete vortices and separated shear layers are expressed by a row of discrete vortices. A combination of the discrete vortex method with the panel method, in which a potential flow around bluff bodies is expressed by a set of singular points distributed on the body surface, has been applied for the numerical simulations of separated flows around bluff bodies. In the calculations bluff bodies are expressed by sets of discrete bound vortices. In the calculations the procedures to determine the strength and location of the shedding vortex are investigated carefully. A new vortex shedding model is proposed in order to express a separated shear layer as a weak and fine row of vortices for the calculations of separated flows around rectangular cylinders, trapezoidal cylinders and concave cylinders. The results show excellent agreement with experiments.