Drag increment of internal waves generated by horizontally moving spheroid in supercritical regime

A theory on the drag increment of internal waves with a spheroid moving horizontally at a high velocity (or for large internal Froude number) in uniformly vertically stratified fluid (or ocean) is presented in the present paper. A surface source distribution is employed to model a hydrodynamic interaction between the spheroid and the stratified fluid. From theoretical results, it is shown that there exists an asymptote of zero-drag increment in supercritical regimes, where internal Froude numbers are larger than the critical internal Froude numbers. When the spheroid reduces to a sphere, the results in this paper is in good agreement with the previous theoretical and experimental results of the sphere. The project supported by the National Natural Science Foundation of China (40576010) and the Russian Foundation for Basic Research (05-01-00154). The English text was polished by Keren Wang.