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611.
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红外气体分析中环境影响的补偿方法研究 总被引:6,自引:0,他引:6
环境温度、总压影响是红外气体分析中难以有效解决的主要问题之一,本文以二氧化碳气体为测量对象,采用实验手段,单片机和数据自理技术建立了环境温度、总压对红上气体分析影响的补偿数学模型和求解方法,并进行了实验验证,研究的内容为红外气体分析中影响影响的外补偿开始辟了一条新的途径,具有广阔的应用前景。 相似文献
613.
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
614.
通过对一起波音737NG飞机备用液压泵低压灯亮故障的分析,从宏观和整体的角度理解液压系统各部件之间的关联关系,为类似故障的排除提供参考。 相似文献
615.
This paper conducts a simulation study of a novel aircraft environmental control system based on membrane dehumidification(MD-ECS),and compares the system with the up-to-date four-wheel high pressure de-water system(4WHPDW-ECS).Mathematical models for the two systems are established,and a system simulation using a numerical technique is performed to analyze and compare the cooling performance of the two systems.Simulation results show that the cooling capacity of MD-ECS is much higher than that of 4WHPDW-ECS under the same working conditions,indicating that the novel system is theoretically feasible and promising.The effects of the sweep ratio of the membrane dehumidifier on the dehumidification and cooling performance of the system is also investigated. 相似文献
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高压液氧供应系统是我国压力最高的挤压式液体火箭发动机试验台的关键分系统。在系统设计过程中,通过合理布置管路,设计专用固定支架,采用自然补偿和堆积绝热技术,解决了高压低温推进剂系统管路设计中的难题。该系统顺利通过气密性检查和调试,经多次热试车考核,系统稳定可靠,满足设计要求。 相似文献
618.
This paper analyses the eddy current loss in Homopolar magnetic bearings with laminated rotor cores produced by the high speed rotation in order to reduce the power loss for the aerospace applications. The analytical model of rotational power loss is proposed in Homopolar magnetic bearings with laminated rotor cores considering the magnetic circuit difference between Homopolar and Heteropolar magnetic bearings. Therefore, the eddy current power loss can be calculated accurately using the analytical model by magnetic field solutions according to the distribution of magnetic fields around the pole surface and boundary conditions at the surface of the rotor cores. The measurement method of rotational power loss in Homopolar magnetic bearing is proposed, and the results of the theoretical analysis are verified by experiments in the prototype MSCMG. The experimental results show the correctness of calculation results. 相似文献
619.
Three-dimensional computational fluid dynamics analyses have been employed to study the compressible and turbulent flow of the shock train in a convergent–divergent nozzle. The primary goal is to determine the behavior, location, and number of shocks. In this context, full multi-grid initialization, Reynolds stress turbulence model (RSM), and the grid adaption techniques in the Fluent software are utilized under the 3D investigation. The results showed that RSM solution matches with the experimental data suitably. The effects of applying heat generation sources and changing inlet flow total temperature have been investigated. Our simulations showed that changes in the heat generation rate and total temperature of the intake flow influence on the starting point of shock, shock strength, minimum pressure, as well as the maximum flow Mach number. 相似文献
620.