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541.
Bershad N.J. Merryman P. Sklansky J. 《IEEE transactions on aerospace and electronic systems》1974,(2):245-254
The theory of ?continuous learning? is applied here to the design of nonlinear sampled-data trackers. This theory provides a continuous-motion approximation of the discrete or sampled motion of the actual tracker. The theory prodicts the transient-response performance of the tracker as well as the mean-square errors caused by noise and statistical fluctuations in the signal. Numerical examples of first-order and second-order trackers designed by this technique are presented. These examples illustrate the adaptive behavior predicted by the technique. In one of these examples the trade-off between transient-response performance and the suppression of noise-induced tracking errors is demonstrated. 相似文献
542.
Using the results of numerical modeling of nonstationary gas hydrodynamic working processes in the gas conduit variable section channel when removing and cooling hot gases of different purpose technical plants, an engineering technique has been developed to provide the gas conduit operation under limitations on the flow temperature in the outlet plant section. A multiparametric area of permissible gas conduit operation connecting the characteristics of technical plants, gas conduit and water feeding system is presented. 相似文献
543.
E. N. Bogomolov S. M. Piotukh I. A. Simonov V. A. Uglov 《Russian Aeronautics (Iz VUZ)》2010,53(4):416-420
A method for calculating the flowrate of the gas flowing through the cellular insert cells over the labyrinth seal strip is proposed. The gas density is taken to be average with respect to the decisive section. It is assumed that jets flowing out of cells disrupt the direct flow of the labyrinth seal. A practical implementation of the method is confirmed by the known experimental data. 相似文献
544.
N. N. Inozemtsev 《Russian Aeronautics (Iz VUZ)》2010,53(4):443-449
A problem of applying closed multiloop thermodynamic cycles with mixing of dissimilar working gases in spacecraft power plants has been considered. The advantage of these cycles that is due to reduction of a heat quantity being rejected into space has been shown for ecologically clean generation of electric energy in prolonged space flights. 相似文献
545.
The mathematical models of the solid-liquid flow regimes in the vertical cylindrical channel are described. A two-speed flow based on the solid-liquid phase interaction is considered. The problem was numerically solved and the calculation results were compared with experimental data. 相似文献
546.
547.
High speed flows inside cavities are encountered in many aerospace applications including weapon bays of combat aircraft as well as landing gear. The flow field inside these cavities is associated with strong acoustic effects, unsteadiness and turbulence. With increasing emphasis on stealth operation of unmanned combat air vehicles and noise concerns near airports, cavity flows attracted the interest of many researchers in aerodynamics and aeroacoustics. Several attempts were made using wind tunnel experimentation and computational fluid dynamics analyses to understand the complex flow physics associated with cavity flows and alleviate their adverse effects via flow control. The problem proved to be complex, and current research revealed a very complex flow with several flow phenomena taking place. With the aid of experiments, CFD methods were validated and then used for simulations of several cavity configurations. The detached-eddy and large-eddy simulation methods proved invaluable for these studies and their application highlights the need for advanced turbulence simulation techniques in aerospace. The success of these methods and a summary of the current status of the experimental and computational progress over the past twenty years is summarised in this paper. 相似文献
548.
549.
Prokhorov M. I. Bogomolov V. V. Bogomolov A. V. Iyudin A. F. Kalegaev V. V. Myagkova I. N. Osedlo V. I. Svertilov S. I. 《Cosmic Research》2022,60(4):241-253
Cosmic Research - The use of the normalized range method for an analysis of the fast variability of electron fluxes in near-Earth space is proposed. This method makes it possible to conclude... 相似文献
550.
Yu. G. Markov M. V. Mikhailov V. V. Perepelkin V. N. Pochukaev S. N. Rozhkov A. S. Semenov 《Cosmic Research》2016,54(2):155-163
The necessity of taking many force components disturbing spacecraft (SC) orbits into account is demonstrated for the example of forecasts of GLONASS ephemerides. The disturbances of SCs in high-earth orbits (HEO) and low-earth orbits (LEO) are systematized, and the degree of their effect on SC motion is estimated. Disturbance models are developed that provide essential increases of the accuracy of one-day forecasts of GLONASS and GPS ephemerides. Modeling results are presented that allow, depending on the required accuracy of SC orbit forecasts, the determination of the necessary list of disturbances included in the model. 相似文献