Experimental Investigation of a Gas Dynamic Thrust Vector Control for Hypersonic Space Planes.

An experimental investigation was carried out to find the effect of a strut spanning across the width of a single expansion ramp of a laboratory model scramjet thruster as a thrust vector control device. Cold flow tests were conducted with operating total pressures ranging from 4 bar to 10 bar and the thruster exhaust was to ambient atmosphere. The mass flow rate varied from 0.105 kg/s to 0.263 kg/s. Experiments were conducted by varying the strut height at different operational total pressures to find if any thrust vector control could be achieved to supplement the maneuverability of hypersonic vehicle with aerodynamic control. The laboratory model consisted of an isolator, a divergent combustor followed by a single expansion ramp. Except the side walls, the thruster was fabricated with stainless steel. A high quality acrylic sheet was used for internal flow visualization by a schilieren system. The wall pressure was recorded at different locations from the combustor inlet to ramp trailing edge. Shock pattern was studied from the schilieren images and it was observed that an increase in strut height caused a downward deflection of the exhaust. From the wall pressure distribution, two dimensional side force coefficient and pitching moment coefficient were calculated and the effect of strut height variation on the above coefficients was plotted. Results from experiments indicated that the presence of the strut yielded noticeable changes in side force and pitching moment. The increase in strut height provided exhaust stream directional changes which may be useful in maneuvering the vehicles employing scramjet propulsion system.

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Increasing the efficiency of an interceptor system for rocket engine thrust vector control

Technical mechanics ◽

10.15407/itm2020.04.013 ◽

2020 ◽

Vol 2020 (4) ◽

pp. 13-28

Author(s):

H.O. Strelnykov ◽

◽

O.L. Tokareva ◽

O.D. Ihnatiev ◽

N.S. Pryadko ◽

...

Keyword(s):

Supersonic Flow ◽

Vector Control ◽

Rocket Engine ◽

Control Force ◽

Thrust Vector Control ◽

Engine Thrust ◽

Gas Dynamic ◽

Working Medium ◽

Combined Control ◽

Thrust Vector

This work is concerned with studying the static and dynamic characteristics of the gas-dynamic (interceptor) subsystem of a combined system for thrust vector control and identifying ways to increase its efficiency. The combined control system includes a mechanical and a gas-dynamic subsystem. The gas-dynamic thrust vector control subsystem is the most important and reliable part of the combined control system. Consideration is given to disturbing the supersonic flow by installing a solid obstacle (interceptor) in the middle part of the rocket engine nozzle. An important advantage of this method to gas-dynamically control the rocket engine thrust vector is that the thrust vector control loss of the specific impulse is nearly absent because the control force is produced without any consumption of the working medium. Injection through the interceptor protects it against exposure to the nozzle supersonic flow and produces an additional lateral force. By now, the optimum height of the mass supply opening in the interceptor that maximizes the control force has not been determined, and the dynamic characteristics of this system have not been studied. The aim of this work is to find the optimum position of the opening for working medium supply through the interceptor that maximizes the added control force and to determine the effect of the transfer functions of the interceptor system components on the characteristics of the control force production transient. As a result of the study of the static characteristics of the supersonic flow disturbance in a nozzle with an interceptor through which a secondary working medium is injected, it is concluded that in terms of thrust vector control efficiency and interceptor protection the injection opening should be situated in the upper part of the interceptor. The transfer function of interceptor control of the liquid-propellant rocket engine thrust vector is obtained with account for the production of an additional control force by the injection of a liquid propellant component. It is found that the loss of stability of the operation of an injection interceptor unit depends on the transient of the working medium injection control valve.

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An operation algorithm for the combined thrust vector control system of a rocket engine

System technologies ◽

10.34185/1562-9945-4-123-2019-06 ◽

2019 ◽

Vol 4 (123) ◽

pp. 58-66

Author(s):

Olena Leonidivna Tokareva ◽

Natalia Serhiivna Priadko ◽

Ternova Vitaliivna Ternova

Keyword(s):

Control System ◽

Vector Control ◽

Input Signal ◽

High Frequency ◽

Rocket Engine ◽

Vector System ◽

Thrust Vector Control ◽

Gas Dynamic ◽

Thrust Vector ◽

Vector Control System

The new combined rocket engine (RE) control system consists of combining various control systems - mechanical thrust vector control system (MTVCS) and gas-dynamic one (GDTVCS) within one bifunctional system that performs the functions of controlling and stabilizing the rocket stage flight. Previously it was shown that the MTVCS speed has limit, since with its speed increase the sensitivity to high-frequency random disturbances rises, which increases random errors. In addition, the system performance rise leads to an increase in the mass and dimensions of the steering drive of the engine swing. As part of the combined system, GDTVCS supplies any given speed requirements, and MTVCS provides maximum control efforts with minimum drive power and maximum element simplicity of the thrust vector control system as a whole. However, there is a problem of rational function distribution between subsystems and coordination of their functioning. For automatic control of the RE thrust vector, the input data are angle deviations in a certain plane, which characterize the direction violations of the installation.The purpose of the work is to study the input signal characteristics of the thrust vector system of steering engines applied to the combined RE control system and the design of an optimal algorithm for its operation.There were analyzed possible determining methods for the trend existence of the input signal on the characteristic RE operation intervals and method was proposed for selected trend using. This made it possible to develop an algorithm for the functioning of the combined (mechanical and gas-dynamic) thrust vector control system of the rocket engine. The created algorithm provides the processing of the TVCS input signal with the selection of the deterministic (static) component (trend) and high-frequency signal oscillations (deviations from the trend). The trend type of the deviation angle perturbation of the RE thrust vector is also taken into account. The typical dependence of the output control actions for the steering RE on the input signals at different operation time intervals is investigated.The developed algorithm allows optimal separating (in terms of energy consumption for creating control efforts) the subsystem functions of the combined RE thrust vector control system, to improve the quality and reliability of the flight control system of the rocket stage.

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Mathematical model of gas dynamics of a nozzle channel with a gas-dynamic method of thrust vector control using a porous insert

Journal of Physics Conference Series ◽

10.1088/1742-6596/2094/4/042081 ◽

2021 ◽

Vol 2094 (4) ◽

pp. 042081

Author(s):

N A Brykov ◽

V Yu Kaun ◽

A A Yatsenko

Keyword(s):

Vector Control ◽

Gas Dynamics ◽

Dynamic Method ◽

Fundamental Parameter ◽

Propulsion Systems ◽

Porous Insert ◽

Thrust Vector Control ◽

Gas Dynamic ◽

Wide Range ◽

Thrust Vector

Abstract The ability to change the magnitude and direction of the thrust vector is a fundamental parameter of the propulsion systems of aircraft. A wide range of methods for controlling these quantities has been developed, which are used depending on the design schemes. The article discusses the organization of the gas-dynamic method of thrust vector control, carried out using distributed gas injection through a porous insert.

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