Calculating the Added Mass Matrix of an Airship Using Boundary Element Method

In this paper the boundary element method is used to calculate the added mass matrix of an airship. Here, the governing equations are desecrated on the triangular computational cells on the surface of the airship geometry. The computational grid cells are generated on the surface of the body using the Gambit software and inserted to the BEM Fortran code. First, in order to validate the numerical code, the added mass of a sphere and ellipsoid with two different fineness ratio (a/b=2, 3.85) is obtained and the results are compared with the analytical results. The BEM results are in a very good agreement with the analytical results. Then the BEM code is used to calculate the envelope added mass matrix with NPL and GNVR body profile which are two common body profiles in airships. Finally, the simulation is conducted for the whole airship with fins and gondola and the added mass matrix is obtained for two envelope profiles.