Гапонов С.А., Смородский Б.В. «Ламинарный сверхзвуковой пограничный слой бинарной смеси газов» Вестник Новосибирского государственного университета. Серия: Физика, 11, № 1, с. 5-15 (2016)

Theoretical investigation of the properties of a compressible binary-mixture boundary-layer in the framework of local self-similar boundary-layer equations. We have considered the problem, when the foreign gas of various molecular weights – lighter and heavier than air – has been injected into the flat-plate boundary-layer through the permeable model surface. Computations of the binarymixture velocity, density and temperature profiles as well as foreign gas concentration in such boundary layers at different Mach numbers have been performed. It has been found that increase of a foreign gas injection leads to a monotonous decrease of the skin friction and heat transfer coefficients. It has been established that at free stream Mach number M<2 action of a heavy gas injection from the model surface into the boundary layer is similar to the action of the model cooling. This injection increases the density of the mixture near the wall. As a result, the profiles of the supersonic boundary layer are modified in such a way that the boundary-layer linear stability should be increased with injection of a foreign gas with high molecular weight. This in turn should lead to a shift in position of the laminar-turbulent transition downstream.

Дрясов А.Д., Ермолаев Ю.Г., Косинов А.Д., Семенов Н.В., Семенов А.Н. «Влияние вихревых возмущений на ламинарно-турбулентный переход в сверхзвуковом пограничном слое на скользящем крыле при М = 2,5» Вестник Новосибирского государственного университета. Серия: Физика, 11, № 1, с. 16-22 (2016)

Experimental investigations of the receptivity of a supersonic boundary layer on a swept wing to the vortex perturbations were made at Mach 2.5. A symmetrical wing model with a 45 sweep angle and a 3-percent-thick circular-arc airfoil was used in experiments. The investigation of the vortex disturbances structure generated by a wire was done. It has been shown that the level of disturbances in the free flow increases with increasing wire diameter. The positions of the laminarturbulent transition at different diameters of wire were determined and data of the disturbances development in the model boundary layer were obtained. It was found that an increase in the intensity of vortex disturbances in the free flow leads to an earlier transition. Receptivity coefficients were determined.

Голубев М.П., Шмаков А.С. «О применении упругих покрытий для регистрации поля давления на поверхности модели при сверхзвуковом режиме обтекания» Вестник Новосибирского государственного университета. Серия: Физика, 11, № 1, с. 23-33 (2016)

The work presents the results of application of panoramic interferential technique which is based on elastic layers (sensors) usage to obtain pressure distribution on the flat plate having sharp leading edge. Experiments were done in supersonic wind tunnel at Mach number M=4. Sensitivity and response time are shown to be enough to register pressure pulsation against standing and traveling sensor surface waves. Applying high-frequency image acquiring is demonstrated to make possible to distinguish at visualization images high-speed disturbances propagating in the boundary layer from low-speed surface waves.

Гольдфельд М.А., Захарова Ю.В., Старов А.В., Тимофеев К.Ю. «Щелевой канал как газодинамический источник воспламенения и стабилизации горения в сверхзвуковой камере сгорания» Вестник Новосибирского государственного университета. Серия: Физика, 11, № 1, с. 34-44 (2016)

The original scheme of flame stabilization in the channel at close to cocurrent fuel supply for the fuel combustion of flame stabilization in tne channel at close to cocurrent fuel supply for the temperature of a stream in a zone of fuel-air mixture formation. Computational and experimental investigations of self-ignition and combustion of hydrogen were carried out in the model of combustor chamber with slotted channel (gasdynamical source of ignition) at Mach numbers 3.7 and 5.8 at the entrance. Tests have been performed in hot-shot wind tunnel IT-302M of ITAM SB RAS in a mode of the attached pipe. Numerical study has been performed on the basis of solving the full averaged Navier–Stokes equations, supplemented κ-Q SST turbulence model. Configuration of the slotted channel has been designed with two variants of exit nozzle: with and without geometrical throat. It has been established that at the channel entrance two vortexes with high temperature have been appeared. Temperature has been keeping high in the channel with geometrical throat and at blocking of the slotted channel without throat. It was found that uniform subsonic stream in the channel with geometrical throat has been realized. The stream in the slotted channel without geometrical throat keeps supersonic but Mach number was lower than in the main channel. The structure of the flow at the slotted channel exit is significantly differs for this both cases.

Юсупов Р.Р., Шторк С.И., Алексеенко С.В. «Исследование сильнозакрученного газожидкостного потока в гидродинамической вихревой камере» Вестник Новосибирского государственного университета. Серия: Физика, 11, № 1, с. 45-55 (2016)

The work is devoted to experimental study of one-phase and two-phase swirling flow in a horizontal vortex chamber with a tangential swirler. Special attention is paid to an emergence of unsteady vortex structures. Formation of a precessing vortex core (PVC) in the nozzle has been detected in the case of one-phase flow. Linear dependence of the PVC precession frequency and quadratic dependence of the full pressure drop in the vortex chamber on the fluid flow rate were confirmed experimentally. In the case of two-phase flow a high-speed visualization allowed to reveal the presence of the secondary vortex structures in cylindrical region behind the zone of sudden expansion. Adding a gas phase into the flow leads to a sharp decline of the precession frequency and full pressure drop decrease in the vortex chamber. The frequency smoothly decreases with further increase of gas content and pressure drop changes insignificantly: slightly increases or decreases depending on the water flow rate. At the same time there is a coherent change of the flow’s integral characteristics at changing the flow rates of liquid and gas.

Куйбин П.А., Литвинов И.В., Сонин В.И., Устименко А.С., Шторк С.И. «Моделирование условий закрученного потока на входе в отсасывающую трубу для различных режимов работы гидротурбины» Вестник Новосибирского государственного университета. Серия: Физика, 11, № 1, с. 56-65 (2016)

One of the main sources of powerful pressure pulsations in the fluid flow parts of the hydroturbine at partial load or overload operation regimes is the precessing vortex rope forming due to high residual swirl of the flow downstream the hydroturbine wheel. Numerical simulation and experiments have been performed in order to study the influence of inlet flow conditions in the draft tube on level of the flow pulsations. Numerical calculations have shown that it is possible to reproduce velocity distributions at the draft tube inlet corresponding to different operation regimes of the real hydroturbines using a combination of two blade grids – rotor and stator. Experimental verification of numerical calculations was performed using an aerodynamic test rig and method of 3-d printing for fabrication of the blade grids and draft tube model. Velocity field measurements at entrance of the draft tube conical part making use of an laser-Doppler anemometer and level of the pressure pulsations using acoustic probes have allowed to define correlation between the velocity distribution type and amplitude-frequency characteristics of the flow pulsations which generated by the precessing rope.

Козулин И.А., Кузнецов В.В., Барткус Г.В. «Экспериментальное изучение взрывного вскипания органических жидкостей методом изменения интенсивности лазерного излучения при рассеянии на микропузырьках» Вестник Новосибирского государственного университета. Серия: Физика, 11, № 1, с. 66-72 (2016)

Барткус Г.В., Кузнецов В.В. «Экспериментальное изучение детальной структуры газожидкостного течения в прямоугольном микроканале» Вестник Новосибирского государственного университета. Серия: Физика, 11, № 1, с. 73-79 (2016)

The detailed structure of upward gas-liquid flow of water and nitrogen in a vertical microchannel with a rectangular cross-section 420×280 μm was experimentally investigated. The experiments were conducted using the methods of high-speed video and laser-induced fluorescence. In a wide range of flow rates the characteristic regimes of the gas-liquid flow were defined, velocity of elongated bubbles and the local thickness of the liquid film were measured. The dependence of the local film thickness on the capillary number was determined and it was found that the Taylor Law for rectangular channel is not fully implemented due to the deformation of the interface and the contraction of the liquid into the corners of the channel by capillary force.