NUMERICAL SIMULATION OF THE PHENOMENA DUE TO THE PASSING-BY OF TWO BODIES USING THE UNSTEADY BOUNDARY ELEMENT METHOD

In this paper a numerical analysis was made to investigate the aerodynamic forces surrounding two bodies in relative motion in a fluid at rest in three dimensions. The unsteady boundary element method was employed in the numerical calculations. This method is very convenient for obtaining an approximate expression of the velocity potential, especially for practical use. The passing-by of two spheres in an incompressible perfect fluid which extends to infinity is treated by the present method. The resultant pressure coefficients on two spheres passing each other in opposite directions are calculated and discussed numerically. Numerical examples are presented to show the validity of the present method. The method is also applied to the calculation of the passing-by of two trains in an open area in order to investigate its applicability.