Search academic texts

Information × Registration Number 0224U000696, 0123U100514 , R & D reports Title Synergetics of the vortex state of gradient multiphase flows popup.stage_title Head Voropaiev Hennadii О., д.ф.-м.н. Registration Date 10-01-2024 Organization The Institute of Hydromechanics of the National Academy of Sciences of Ukraine popup.description2 The methods of numerical and physical modeling of flows on structured surfaces that carry out arbitrary movement in the liquid flow and in channels of arbitrary shape have been improved. The influence of numerical modeling parameters on the nature of the flow around a rectangular two-dimensional trench in the range from steady to oscillatory flow regime inside and around the trench, depending on the Reynolds number, is analyzed. On the basis of direct numerical simulation of the flow in a smooth channel and a channel with a rectangular trench, the formation of eddies, their scale and intensity were investigated. Thermal and hydraulic parameters of a smooth channel and a channel with a trench were compared. In the considered range of parameters in the vicinity of the trench, the local heat transfer increases up to 6 times, but the integral changes in the heat flow in the channel do not exceed 25%. Therefore, the trench in this range of Reynolds numbers is a relatively effective intensifier of heat transfer with an energy efficiency coefficient of k=1.19. A series of numerical experiments on the flow around an actively deformable surface showed that, depending on the ratio of the flow parameters and the forced deformation of the streamlined surface, the initially generated planar disturbances can preserve the initial planar structure of the disturbances at a certain distance downstream, transform into quasi-deterministic three-dimensional vortex structures, or quite quickly disintegrate in a cascade process into small-scale vortex formations. Complex testing of the PIV measurement technology in a closed wind tunnel was carried out based on a number of typical bodies and streamlined surfaces. It has been confirmed that with the help of PIV technology it is possible to visualize and measure the flow disturbances inside the dimple, which are most concentrated near its edges. Product Description popup.authors Baskova Oleksandra О. Voskobiinyk Andrii V. Dimitrieva Natalia F Zagumennyi Iaroslav V Korobov Vitalii I Paramonov Yuriy О. Rozumnyuk Natalia V. Shkvar Yevgenii O. popup.nrat_date 2024-01-10 Close