Comparative analysis of computational and experimental studies of hydrodynamic loads on a model of a descent vehicle with inactive propulsion system during a splashdown

The reusable manned spacecraft Federatsiya that is being developed by RSC Energia is supposed to use a landing system based both on parachutes and rocket propulsion, which is expected to achieve an almost zero velocity of the spacecraft at touchdown. ln nominal situations, the spacecraft lands on specially prepared unpaved ground. ln off-nominal situations the spacecraft may have to land on all kinds of surfaces, including water. ln that case, conducting design studies requires the knowledge of hydrodynamic loads on the spacecraft body and its dynamic behavior in water. ln view of the existence of a great variety of splashdown modes, searching for the required parameters using the traditional experimental method that goes back to the development of the Apollo and Soyuz spacecraft is impractical, mostly because of the large scope of required tests and their limited informative value. Therefore, it stands to reason to run computer simulations of the splashdown in state-of-the-art software packages, having done their preliminary validation. This paper discusses the results of testing the FlowVision software package developed by LLC TESlS using experimental data, obtained in tests on the models of Apollo Command Module. It presents data on pressure variations on the spacecraft surface in process of its immersion and its dynamic behavior in water. It demonstrates the advisability of using this package for studying the process of landing of the descent vehicle of the Federatsiya spacecraft.