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961.
962.
The results of studying the characteristics of a two-phase flow being formed during adiabatic water efflux through axisymmetric
cylindrical and Laval nozzle channels are presented. Experiments were carried out with saturated water in the range of initial
pressures 0.6–4.0 MPa. The fluid efflux was performed into the air with atmospheric pressure. The generalizing relations for
calculating thrust pulse and critical flowrate were obtained. 相似文献
963.
Liu JiaFu Fu Yu Zhang Liang Luo Na Wang Weiwei Zhao Dan Wu ZhiGang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(4):1333-1349
Reflectors are very critical space elements and can be used not only as solar collectors/reflectors, telecommunication radio antennas and telescopes but also for dual-usage such as solar sails and solar concentrators to probe and sublimate materials from asteroids when actively controlling the surface shape. In this paper, the surface shape of a slack reflector with negligible elastic deformations will be controlled to be a paraboloid by actively modulating the solar radiation pressure (SRP) force using reflectivity control devices (RCDs) across the reflector. Nonlinear static equilibrium equations for an arbitrary infinitesimal within the reflector along the radial, circumferential and transverse directions are established considering the external modulated SRP force and internal tensions respectively. The coupled radial stress differential governing equation and reflectivity algebraic equation are obtained for the paraboloid reflector by the help of the formulation of an inverse problem based on equilibrium equations previously established. Some analytical and numerical analysis for reflectors with ideal and non-perfect SRP force models are performed respectively. The conclusions concerning about how to control the reflector’s surface shape successfully using allowed reflectivity, resulting in reasonable stress range, moreover, how to get the feasible solutions influenced by the reflector’s size parameters, are all based on the presented analytical and numerical analysis. 相似文献
964.
965.
A. A. Vostrukhin D. V. Golovin A. S. Kozyrev M. L. Litvak A. V. Malakhov I. G. Mitrofanov M. I. Mokrousov T. M. Tomilina Yu. I. Bobrovnitskiy A. S. Grebennikov M. M. Laktionova B. N. Bakhtin A. V. Sotov 《Cosmic Research》2018,56(3):208-212
The results of testing a number of space-based detectors that contain PMTs or high-voltage electrodes for the noise from the microphonics that occurs in the signal path due to external mechanical action have been presented. A method for the vibration isolation of instruments aboard a spacecraft has been proposed to reduce their responsivity to vibrations. 相似文献
966.
967.
The equations of the mathematical model are solved in terms of special functions. The results for the design scheme of the aircraft forebody are obtained with a guaranteed accuracy by the stable method of functional normalization. 相似文献
968.
Bleed air system is one of the most important components of air management system(AMS).It acts as transfer pipes responsible for air supply at high temperature and pressure.The thermal and flow performance of the bleed air system is a key issue for the design of AMS since the characteristics of air source have a great influence on the anti-ice system,the environmental control system and other downstream system in need of high temperature pressurized air.Based on the one-dimensional lumped parameter technology,a computer analysis model of bleed air system is developed in order to analyze the thermal and flow behaviors of the nodal points in the pipeline network.The simulation are performed with a given flight assignment using the analysis model,and the results verify that the system meets the design requirements. 相似文献
969.
Shyh-Biau Jiang Tse-Liang Yeh Li-Wu Chen Jann-Yenq Liu Ming-Hsuan Yu Yu-Qin Huang Chen-Kiang Chiang Chung-Jen Chou 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(10):2673-2679
In this study, we construct a photomultiplier calibration system. This calibration system can help scientists measuring and establishing the characteristic curve of the photon count versus light intensity. The system uses an innovative 10-fold optical attenuator to enable an optical power meter to calibrate photomultiplier tubes which have the resolution being much greater than that of the optical power meter. A simulation is firstly conducted to validate the feasibility of the system, and then the system construction, including optical design, circuit design, and software algorithm, is realized. The simulation generally agrees with measurement data of the constructed system, which are further used to establish the characteristic curve of the photon count versus light intensity. 相似文献
970.
A. A. Ryabov V. I. Romanov V. N. Rechkin Yu. N. Shmotin A. V. Veselov 《Russian Aeronautics (Iz VUZ)》2011,54(4):379-386
A computational technique, developed for analysis of strength, stability and low-cycle durability of GTE exhaust frame complex
structure under operational and emergency loads is described. The presented technique, based on the ANSYS and STAR-CD engineering
analysis software, and self-design software can improve the accuracy and efficiency of calculations, and reduce efforts on
finite element mesh development, performing calculations and processing of results. 相似文献