O.V. Lunina, A.A. Gladkov
a:2:{s:4:"TEXT";s:99:"Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia";s:4:"TYPE";s:4:"text";}
Keywords: Rupture zone, scarp, parameters, aerial photography, UAV, orthophoto, digital terrain model, Cape Rytyi, Lake Baikal
We present materials of aerial photography of Cape Rytyi, a unique and most mysterious place on the northwestern shore of Lake Baikal. Photogrammetric survey was carried out using a DJI Phantom 4 Pro V2.0 UAV and provided an orthophoto and a digital terrain model of an 11.074 km2 area. When deciphering the images obtained in the Rita River deltaic sediments composing the cape, surface ruptures trending north and northeast at 30-150 m from the shore of Lake Baikal were discovered. The ruptures are a clearly localized zone 2.9 km in total length. The performed analysis showed that the structural features of the zone obey the general laws of the development of faults resulted from prevailing extension. It has been established that the formation of the ruptures was predetermined by tectonics and is a secondary effect of resonant oscillations from the M = 5.2 earthquake of 08.13.1962, the epicenter of which was located ~35 km southeast of Cape Rytyi, in the Morskoi fault zone. The seismic event initiated the formation of surface ruptures, which led to a gravitational subsidence of coarse deposits of the fan in the shore zone. It is concluded that the development of modern geomorphologic forms in the peripheral part of the Rita River fan on land is similar to the formation of an underwater topography in the region of the Selenga River delta. It occurs under the influence of seismogenic rupturing and following gravitational movements, which intensify in a water-saturated environment and are subsequently complicated by erosion processes.
Results of an experimental study of the hysteresis of aerodynamic characteristics of NACA 0018 airfoil in the T-124 low-turbulent wind tunnel of low subsonic speeds of TsAGI are reported. The experiments were carried out on the OVP-124 dynamic setup under steady-state conditions with a quasi-static (continuous) increase and decrease of the angle of attack and with forced oscillations of the model over pitch with different amplitudes and frequencies relative to various set angles of attack. In all cases, measured aerodynamic characteristics exhibits a hysteresis related with the presence of a range of attack angles in which stable, non-unique separated-flow structures are observed. On the basis of experimental data obtained, a new approach to the mathematical modeling of the phenomenon of static and dynamic hysteresis of aerodynamic characteristics is developed for use in dynamics problems.
A mathematical model of the process of the unsteady conjugate heat transfer of a thermionic thermal protection system in a supersonic flow around a composite shell is formulated and investigated. Estimates of the effect of evaporation (emission) of electrons from the emitter surface on the reduction of temperature of the composite shell of the protection system were obtained. The effect of different angles of attack on the modes of heat transfer in a multi-element thermionic thermal protection system was examined. Qualitative agreement of calculation results with known data is obtained.
A.A. Zhilin1,2, A.V. Primakov1,2 1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia 2Siberian State University of Water Transport, Novosibirsk, Russia
Keywords: Hartmann generator, wave processes, resonator, off-design jet, pressure distribution, temperature field in the channel
The results of numerical simulation of gas-dynamic flow in the channel of a technical device with a resonant cavity are presented. One period of gas-dynamic loading of structural elements of the resonant cavity has been studied in detail. A complete picture of pressure and temperature field distribution along the resonant cavity channel has been obtained. The maximum and minimum values of pressure and temperature, achieved when the gas flow moves along the resonator channel, have been determined.
The paper describes a study of pressure distribution along the wall of an axisymmetric channel with a straight step. A supersonic gas flow, formed inside the channel, when an external flow with Mach numbers M = 5 and M = 6 moves around an axisymmetric model with internal duct , is considered. A supersonic aerodynamic wind tunnel of a short-term action is used for experiments. The results of measuring the pressure along the channel wall in the flow around the model under study are presented. The data of aerodynamic tests are compared with the results of numerical calculations, and the resulting pressure distributions are compared. It has been established that the nonmonotonic nature of a change in pressure along the wall is caused by the shock waves, which accompany the supersonic gas flow in the channel.
The combustion of hydrocarbon fuel at the Mach number M = 1.7 is studied numerically. A transverse air stream is used to ignite the fuel supplied through the axial injector. The Reynolds-averaged Navier-Stokes equations closed by the k-ε turbulence model are solved. Fuel combustion is simulated using a single reaction approach. The possibility of transonic flow formation has been investigated. The gas-dynamic structure of kerosene fuel combustion is studied for a flow with the Mach number M = 1.7 and stagnation temperature of 1500 K.
A.S. Askarova1,2, V.E. Messerle1,2,3, Saltanat.A. Bolegenova1,2, V.Yu. Maksimov1, Symbat.A. Bolegenova4, A.O. Nugymanova1 1Al-Farabi Kazakh National University, Almaty,Kazakhstan 2Scientific Research Institute of Experimental and Theoretical Physics, Almaty,Kazakhstan 3Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 4Scientific Research Institute of Experimental and Theoretical Physics, Almaty, Kazakhstan
Keywords: heat and mass transfer, numerical simulation, air mixture supply method, reduced boiler load, velocity, temperature, concentration of harmful substances
Computational experiments were carried out using three-dimensional computer modeling methods to determine the effect of various burner arrangements and the method of fuel mixture supply on the main characteristics of heat and mass transfer processes (flow aerodynamics, temperature fields, concentration fields of combustion products) throughout the entire volume of the combustion chamber of a power boiler and at its outlet. It is shown that the use of vortex burners with a swirl of the air mixture flow allows improvement of metabolic processes in the combustion chamber and reduces emissions of harmful substances into the atmosphere both during traditional fuel combustion and at reduced boiler load (partial shutdown of burners).
The article presents results of a numerical simulation of the phenomenon of continuous spin detonation in a hydrogen-oxygen mixture in two-dimensional non-stationary formulation using periodic boundary conditions. The soft-ware implementation of the mathematical model is made in the Ansys Fluent software package. A methodology for adjusting the software package and an algorithm for initiating the detonation process for numerical simulation are presented. The method was verified by calculating and comparing with experimental data the propagation velocity of a plane detonation wave with various diluents. Using the developed modeling technique, the specific impulses and the velocities of continuous spin detonation were determined for fuel excess ratios in the range from 0.56 to 2.4. The simulation results showed good agreement with the results obtained by other authors. Also, the performed numerical simulation has shown that, on the average, the specific impulse of the combustion chamber of a detonation rocket engine is greater than the specific impulse of a liquid-propellant rocket engine by 17%. It is shown that the use of the continuous spin detonation process can significantly reduce the length of the cylindrical part of the combustion chamber and the gas generator of the liquid rocket engine.
The transfer properties of a congruently melting Mg-Li alloy with a lithium content of 30 at. %, considered as a promising ultralight structural material for the aerospace industry, have been studied experimentally. New experimental data on thermal diffusivity ( a ) and thermal conductivity ( l ) have been obtained in the temperature range of 293-777 K with estimated errors of 2 - 4 % and 3 - 5 %, respectively. The results have been compared with the known literature data on thermal conductivity of alloys from the Mg-Li system. A table of recommended temperature dependences for a and l of the studied composition has been developed.
On January 30, 2022, Sergey V. Stankus, the prominent scientist working in the area of thermophysics, Doctor of Physics and Mathematics and Chief Researcher of the Institute of Thermophysics SB RAS, became 70 years of age.
