Abstract
In numerical simulations of developing flows in space, the computational domain has to be truncated from the unbounded physical domain. When the finite difference method is used, the Sommerfeld radiation condition (SRC) is often used. However it is not clear which value of the convective velocity is appropriate for jets. We compare the four different convective velocities: the mean velocity over the exit boundary (SRC1), the arithmetic mean of the maximum and the minimum velocity at the exit boundary (SRC2), the local instantaneous velocity (SRC3) and the numerical velocity calculated from Orlanski’s formulation (SRC4). The test problems are flows which Lamb dipole moves in uniform flow. It is shown that SRC4 gives good results without reflection and deformation of the vortex.
