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1.
Kugusheva A. D. Kalegaev V. V. Vlasova N. A. Petrov K. A. Bazilevskaya G. A. Makhmutov V. S. 《Cosmic Research》2021,59(6):446-455
Cosmic Research - The results of an analysis of the space–time characteristics and dynamics of precipitations of magnetospheric electrons with energies in the range from 0.1 to 0.7 MeV are... 相似文献
2.
Cosmic Research - Using the Pontryagin maximum principle and the Kustaanheimo–Stiefel variables, the spatial problem of optimal launching into a given orbit of a spacecraft (SC) controlled by... 相似文献
3.
Yu. M. Ignatkin P. V. Makeev V. I. Shaidakov A. I. Shomov 《Russian Aeronautics (Iz VUZ)》2018,61(3):396-403
The research is conducted of aerodynamic performance of the Mi-8 helicopter main rotor in the hover state and the vertical descent state, including vortex ring states (VRSs). Total and distributed aerodynamic performance, wake patterns, and main rotor flow patterns are calculated. The findings and results were compared with those provided by other researchers. 相似文献
4.
G. Uma P.S. Brahmanandam V.K.D. Srinivasu D.S.V.V.D. Prasad P.V.S. Rama Rao 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(7):1736-1743
In this research, it is presented the daytime amplitude scintillations recorded at VHF frequency (244 MHz) at an Indian low-latitude station, Waltair (17.7°N, 83.3°E) during seven continuous years (1997–2003). Contrary to the nighttime scintillation seasonal trends, the occurrence of daytime scintillations maximizes during summer followed by winter and the equinox seasons. The fade depths, scintillation indices and the patch durations of daytime scintillations are meager when compared with their nighttime counterparts. A co-located digital high frequency (HF) ionosonde radar confirms the presence of sporadic (Es) layers when daytime scintillations are observed. The presence of daytime scintillations is evident when the critical frequency of the Es-layer (foEs) is ≥4 MHz and Es-layers are characterized by a highly diffuse range spread Es echoes as can be seen on ionograms. It is surmised that the gradient drift instability (GDI) seems to be the possible mechanism for the generation of these daytime scintillations. It is quite likely that the spread Es-F-layer coupling is done through polarization electric fields (Ep) that develop inside the destabilized patches of sporadic E layers, which are mapped up to the F region along the field lines as to initiate the daytime scintillations through the GDI mechanism. Further, the presence of additional stratification of ionosphere F-layer, popularly known as the F3-layer, is observed on ionograms once the Es-layers and daytime scintillations are ceased. 相似文献
5.
A. N. Sabirzyanov A. I. Glazunov A. N. Kirillova K. S. Titov 《Russian Aeronautics (Iz VUZ)》2018,61(2):257-264
Multiparameter studies of the discharge coefficient dependence on the nozzle geometry and the presence of a condensed phase in combustion products were performed. The simulation results obtained satisfactorily agree with the well-known generalized data. The modern computational fluid dynamics methods were shown to be able to refine the generalized empirical relations. 相似文献
6.
E. R. Muslimov E. Hugot M. Ferrari T. Behaghel N. K. Pavlycheva 《Russian Aeronautics (Iz VUZ)》2018,61(1):1-7
The possibility of constructing an optical scheme of a telescope for a small satellite based on mirrors with freeform surfaces and a curved photodetector is considered. It is shown that the use of a new element base allows the effective area of the main mirror to be maximized and the field of view up to 9.4 times to be increased in comparison with the classical scheme of the Ritchey–Chretien scheme in ensuring the high image quality. 相似文献
7.
R. A. Masterson M. Chodas L. Bayley B. Allen J. Hong P. Biswas C. McMenamin K. Stout E. Bokhour H. Bralower D. Carte S. Chen M. Jones S. Kissel F. Schmidt M. Smith G. Sondecker L. F. Lim D. S. Lauretta J. E. Grindlay R. P. Binzel 《Space Science Reviews》2018,214(1):48
The Regolith X-ray Imaging Spectrometer (REXIS) is the student collaboration experiment proposed and built by an MIT-Harvard team, launched aboard NASA’s OSIRIS-REx asteroid sample return mission. REXIS complements the scientific investigations of other OSIRIS-REx instruments by determining the relative abundances of key elements present on the asteroid’s surface by measuring the X-ray fluorescence spectrum (stimulated by the natural solar X-ray flux) over the range of energies 0.5 to 7 keV. REXIS consists of two components: a main imaging spectrometer with a coded aperture mask and a separate solar X-ray monitor to account for the Sun’s variability. In addition to element abundance ratios (relative to Si) pinpointing the asteroid’s most likely meteorite association, REXIS also maps elemental abundance variability across the asteroid’s surface using the asteroid’s rotation as well as the spacecraft’s orbital motion. Image reconstruction at the highest resolution is facilitated by the coded aperture mask. Through this operation, REXIS will be the first application of X-ray coded aperture imaging to planetary surface mapping, making this student-built instrument a pathfinder toward future planetary exploration. To date, 60 students at the undergraduate and graduate levels have been involved with the REXIS project, with the hands-on experience translating to a dozen Master’s and Ph.D. theses and other student publications. 相似文献
8.
A. V. Bogatyi R. V. El’nikov I. P. Nazarenko G. A. Popov S. A. Semenikhin 《Russian Aeronautics (Iz VUZ)》2018,61(3):445-451
The paper presents the research results of the effect of a capacitor energy storage device configuration on the specific characteristics of advanced modern propulsion systems based on the ablative pulsed plasma thrusters (APPT). These thrusters are designed to perform specific tasks within the small spacecrafts with the onboard power capacity up to 200 W. 相似文献
9.
In the paper, the problem of designing interplanetary trajectories with several swing-bys and deep-space maneuvers is solved using the method of virtual trajectories developed by the authors. The algorithms for the calculation of both heliocentric and planetocentric trajectory arcs are presented, including the case of resonant trajectories. The results of applying the method of virtual trajectories to the problem of designing an interplanetary transfer to Jupiter are given and compared with the baseline trajectories for the Juno, Europa Clipper, and Laplace missions. 相似文献
10.
F. Dehaeze G. N. Barakos A. N. Kusyumov S. A. Kusyumov S. A. Mikhailov 《Russian Aeronautics (Iz VUZ)》2018,61(1):40-47
This paper applies the Detached-Eddy Simulation (DES) method to resolve a larger part of the flow spectrum around rotor blades in hover and forward flight. A comparison between DES and Unsteady Reynolds–Averaged Navier–Stokes simulation was carried out for the case of a forward flying rotor suggesting that DES has great potential for rotor applications. 相似文献