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The paper aims to determine the optimal geometry, the control law and the operational limits of a supersonic air inlet; its operation control consists of its central cone positioning, with respect to the flight Mach number, keeping in sight the necessity of a suitable parameters' distribution into engine's combustion chamber. Inlet's optimal architecture shall be determined (based on an algorithm regarding the maximization of the total pressure recovery), using basic planar geometry principles. Based on the optimal geometry of the inlet, its flow rate characteristic and its control law, as well as inlet's operation limits were calculated and graphically represented. [ABSTRACT FROM AUTHOR]

This paper deals with a supersonic air inlet Laval-type. Based on thermo- and gasdynamic phenomena, the authors have determined the possibilities of Laval-type intake starting process; the starting envelope of the intake was also defined and graphically depicted. Some operating regimes of the intake, correlated to engine's operation were studied and intake's adjusting possibilities were described, as intake's work-lines; these lines were depicted on intake's operational envelope and some control law(s) were determined with respect to the worklines. Possible control architecture may be emphasized. [ABSTRACT FROM AUTHOR]

The paper deals with an automatic system meant to control an air inlet designed for a supersonic aircraft. Starting from the system composition and its constructive scheme, the mathematical model was built up and the transfer function was also determined. Mathematical model's coefficients were calculated or estimated based on inlet's control law and on other similar systems coefficients calculation. Some simulation were performed and the stability and the quality of the control system were evaluated, for different flight regimes. The study is useful for similar inlet's control architecture possibilities evaluation. [ABSTRACT FROM AUTHOR]

The paper deals with an air inlet meant to equip a trisonic aircraft. Starting from the shock-wave system geometry (two external waves and two internal waves), one has applied an algorithm based on inlet's efficiency maximization, for the most employed flight regime, in order to determine its optimal architecture (optimal angles for the centerbody and the cowl's lip), as well as its characteristic maps. In order to assure a better adapting to aircraft flight regime, one has determined inlets centerbody positioning with respect to the flight Mach number, which may be used as inlet's control law. The study is useful for further inlet's automation possibilities analysis, as well as for similar inlets architecture establishing. [ABSTRACT FROM AUTHOR]

The paper deals with a plan supersonic inlet with external compression and mobile panel and studies its control system, based on the second oblique shock-wave positioning and its total pressure ratio recovery. The system's gas-dynamic conditioning and control criteria are determined. The author has established the system's non-linear mathematical model and, finally, the linear non-dimensional model; the block diagram with transfer functions description, based on the above-mentioned models was also provided. Some simulations, concerning the system's stability and quality were performed; furthermore, some conclusions and comment concerning system's time behavior were issued. [ABSTRACT FROM AUTHOR]

The paper studies a rectangular supersonic inlet for a 2.5 Mach aircraft. Inlet's architecture was chosen in order to assure a wide range of flight regimes (from low regimes of taxi and take-off until high supersonic regime), so it was built with a mobile panel. Applying an algorithm based on inlet's efficiency maximization, the optimal architecture for the most employed flight regime was determined and inlet's characteristics maps for a fixed geometrical configuration were obtained. In order to obtain the flow characteristics improvement, an adjusting law for the mobile panel was imagined and, consequently, some new characteristics maps issued; a complementary law was also described and established. The study is useful for further inlet's automation possibilities analysis and also for combined control law(s) issuing, as well as for similar inlets architecture establishing. [ABSTRACT FROM AUTHOR]

Magneto hydrodynamic (MHD) power generation system has an important potential application in high-speed aero craft. According to the principles of MHD power generation, shock tunnel and ionization, a supersonic MHD power generation system is developed and introduced in this paper. Helium is used for driver gas and argon for driven gas. Equilibrium contact surface operating mode is selected to obtain high temperature, and the K2CO3 powder seed is added into the driven section so that the supersonic flow is electric. When M=2.0 and B=0.5T, the power generation system is set up to know the experimental conditions. The nozzle entry total pressure is about 0.35MPa while total temperature about 3965.1K, and the nozzle exit velocity is calculated 1530.8m/s. A preliminary experimental investigation is at length carried out by measuring the voltage and current of the segmented MHD power generation channel. Average electrical conductivity is estimated to be 15S/m approximately. When load factor is 0.5, the maximum power density of this MHD power generation channel is about 2.195MW/m3, while the maximum value of enthalpy extraction rate tends to be about 0.255%. [ABSTRACT FROM PUBLISHER]

When the gas mixture with distinguished molecular masses flows in the field of macroscopic parameter gradients, the separation of gases occurs, accompanied in some conditions by strong energy transformation. We report the results of studying a new class of rarefied gas dynamic strongly non-equilibrium flows. The convergent supersonic flow of the gas mixture may result in the formation of relatively dense cloud of gas enriched by heavy component with the temperature elevated much higher than the stagnation temperature of the undisturbed flow. Such effects are the stronger the larger is the disparity of molecular masses. The conceptual idea of these phenomena is confirmed quantitatively by direct statistical simulation. In the particular case at some rarefaction for mixture 97.5%He+2.5%Xe the temperature in almost continuum clouds, isolated from the wall, has exceeded the stagnation temperature 1.5 times and more. We propose to use the discovered and studied gas dynamic schemes for fundamental researches of physicochemical properties in gases and for use in promising vacuum technologies. Special interest arises in the exploration and utilization of polyatomic gas energy transformation [ABSTRACT FROM AUTHOR]

The stability of vortical disturbances propagating at an angle to the main flow in a nonequilibrium compressible supersonic boundary layer has been investigated. The dependences of the critical Reynolds number on the degree of nonequilibrium and on the Mach number were defined at different angles of wave propagation. It was calculated the time of explosive instability, which realized on stage of nonlinear critical layer. The increment of secondary instability versus degree of non-equilibrium S and amplitude of primary equilibrium solution was founded. [ABSTRACT FROM AUTHOR]