Sadovskiy Ivan Alexeevich

Scopus Publications

Experimental study on the influence of the change in the velocity profile on stability of disturbances in the Blasius boundary layer
I. A. Sadovskii, M. M. Katasonov, V. V. Kozlov
Thermophysics and Aeromechanics, 2024
The influence of the change in the velocity profile on stability of the Tollmien-Schlichting waves in the Blasius boundary layer is studied experimentally. The experiment is performed with a flat plate model in a low-turbulence wind tunnel T-324 at the freestream velocity U ∞ = 9 m/s. Hot-wire anemometry is applied for measurements. The results show that a distributed action on the Blasius boundary layer through a hydrodynamically smooth surface leads to attenuation of the amplitude of the naturally excited Tollmien–Schlichting wave almost by two orders of magnitude. This distributed action leads to changes in flow stability. The experimental results reveal that the distributed action is more effective than the action onto the flow through a slot, other conditions being identical.
Experimental study of perturbations modeled by a membrane in 2D and 3D boundary layers
I A Sadovskii, M M Katasonov
Journal of Physics Conference Series, 2021
The work is devoted to experimental studies of the dynamics of the development of perturbations introduced by a membrane under various conditions. The studies were carried out under conditions of a low and moderate degree of free-flow turbulence. It is shown that the impulsive motion of the membrane generates a localized longitudinal structure in the boundary layer, as well as wave packets at its fronts. A circular membrane generates wave packets consisting of forward and oblique waves, while a rectangular membrane generates predominantly forward waves. A moderate degree of turbulence inhibits the development of wave packets at the linear stage and intensifies at the nonlinear stage. The separation of the boundary layer stimulates an increase in the amplitude of the wave packets.
The Distributed-Suction Effect on the Development of Disturbances at the Nonlinear Stage of Their Evolution in the Boundary Layer
V. V. Kozlov, G. R. Grek, M. M. Katasonov, V. I. Kornilov, I. A. Sadovskii
Doklady Physics, 2020
The results of experimental investigations into the effect of distributed suction through a finely perforated permeable section on the spatial development of disturbances at the nonlinear stage of their evolution in the boundary layer of a straight wing are presented. It is shown that distributed suction makes possible reducing the intensity of both natural pulsations of the boundary-layer velocity and artificial ones generated by an external acoustic field at the fundamental frequency and its harmonics by two orders of magnitude. Affecting significantly the average flow, suction rules out the turbulent state of the boundary layer below the impact area and shifts the flow separation keeping it in the laminar state.
Features of the interaction of localized free-stream disturbances with the straight and swept wing boundary layer
M M Katasonov, V V Kozlov, A M Pavlenko, I A Sadovskii
Journal of Physics Conference Series, 2019
Abstract Under the conditions of a model experiment, the features of the appearance and spatial development the boundary layer disturbances – wave packets (precursors) and longitudinal localized structures were studied. Localized disturbances were created artificially upon local exposure of an external source to the boundary layer of the straight and swept wing with a low turbulence level of incoming flow. Wave packets formed near the fronts of longitudinal localized structures. The studies were carried out in a subsonic low-turbulent wind tunnel. Flow perturbations were recorded using a constant-temperature hot-wire anemometer.
Modelling of the boundary layer disturbances by localized effect of the round membrane
M M Katasonov, V V Kozlov, A M Pavlenko, I A Sadovskii
Journal of Physics Conference Series, 2019
Abstract The spatial development of the flat plate boundary layer disturbances by the hot-wire anemometry is experimentally investigated. Controlled disturbances were introduced into the laminar flow by means of a round membrane located on the surface of the model. The impulse motion of a round membrane leads to the formation of longitudinal localized structures and wave packets in the boundary layer. Wave packets consist of a set of straight and oblique waves, differing in their propagation characteristics. The development of wave packets downstream is consistent with the linear theory of hydrodynamic stability.
Modelling of the boundary layer perturbations by localized controlled impact
M. M. Katasonov, V. V. Kozlov, A. M. Pavlenko, I. A. Sadovskii
Aip Conference Proceedings, 2019
The cycle of experimental investigations showed that the applied method of introducing controlled perturbations allowed to quantitatively and qualitatively investigate the occurrence and development of artificial disturbances in the subsonic boundary layer. The detected feature of localized impact consists in the simultaneous excitation of various types of disturbances in the boundary layer, such as longitudinal streaky structures and wave packets. The explicit correlation of the characteristics and features of development between the generated in the experiment perturbations and intrinsic boundary layer perturbations allow to conclude about the general nature of the perturbations under study, regardless of the way they are excited.