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Information × Registration Number 0223U000676, 0122U000800 , R & D reports Title Investigation of hydrodynamics and stability of unsteady motion of bodies when crossing the free boundary of liquid in the regimes of supercavitation and unsepatated flow popup.stage_title Head Savchenko Yurii M., д.т.н. Registration Date 17-01-2023 Organization The Institute of Hydromechanics of the National Academy of Sciences of Ukraine popup.description2 A series of studies on the water entry of a disk at small angles to the free surface was continued. The pneumatic catapult was modernized in order to expand a possibility of performing experimental studies of the water entry hydrodynamics and stability. A test rig for the experimental study of the supercavitating model vertical water exit was developed and assembled, preliminary tests were carried out. A mathematical model and methods of computer simulation of high-speed motion of bodies in water have been developed, including the water entry and the water exit of supercavitating models. It was established that the atmospheric air eruption into the cavity when the model exits the water leads to a significant slowing down of the cavity collapse process. It was shown that during water exit, both the angle of attack and the angular velocity of the model can change dramatically due to the sliding force of the model along the cavity wall ceases to be compensated by the transverse force on the cavitator. Formulations of steady and unsteady problems of calculating the steady flow of an incompressible fluid around elongated bodies of revolution of a special unseparated shape moving horizontally near a free surface were made and their solutions were obtained. Analytical expressions for the pressure distribution on the body surface and values of the vertical velocity on the undisturbed water surface were obtained. A numerical solution of the nonlinear problem of steady gravity flow in a channel with arbitrary topography of the bottom covered with an elastic ice cover was obtained. Two solutions corresponding to single waves of the perturbed and soliton types in the absence of ice cover were obtained. In the case of an ice sheet, the obstacle generates a wave at the interface downstream of the obstacle. It is shown that for some combinations of obstacle size and Froude number, a stable solution may not exist, especially near the critical Froude number.   Product Description popup.authors Ivanyuk Volodymyr F. Vlasenko Yurij D. Kashirikhin Leonid P. Kyselyov Taras P. Kozenko Oleg M. Manova Zinaida I. Naumova Olena I. Nesteruk Ihor G Savchenko Georgii Yu. Savchenko Yuriy Mykolayovych Semenenko Volodymyr M. Semenov Yuriy A. Temerov Anatoliy S. popup.nrat_date 2023-01-17 Close