• International Journal of Fluid Machinery and Systems
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• v.9 no.4
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• pp.354-361
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• 2016

This study aims to identify aerodynamic characteristics of the ramp tab, a mechanical deflector, by conducting a non-combustive experiment using compressed air and supersonic flow test equipment. With the ramp tabs installed symmetrically and asymmetrically on the outlet of the supersonic nozzle, the structure of the flow field, the thrust spoilage, the thrust deviation angle, and the lift/drag coefficients were derived and analyzed. The results show that the asymmetrically-installed ramp tabs are advantageous relative to the symmetrically-installed tabs in terms of the performance of thrust vector control, thrust deviation angle, and lift coefficient.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.7
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• pp.1248-1254
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• 2010

Authors conducted a deduction of some parameters using the magnetic equivalent circuit method and a verification study of the thrust force control algorithm of a rotary-typed small-scaled linear induction motor for a railway transit. In a LIM, it is possible to express the parameters of the magnetic equivalent circuit into a function of the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. It means that the LIM properties can be changed considerably by the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. So, authors analyzed a tendency of changes of the magnetic equivalent circuit parameters and the LIM characteristics by changing of the airgap of the secondary aluminium plate of a rotary-typed small-scaled LIM. And authors conducted a verification study of the indirect vector control algorithm with constant slip frequency by using the rotary-typed small-scaled LIM tester set on the basis of the calculated LIM parameters. Finally authors accomplished a research on applicability for LIM railway transit.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.4
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• pp.30-35
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• 2009

Effective-pivot effects on the thrust vector control performance of the flexible seal nozzle to be used to control the flight direction of missile were investigated by computer simulation. $2^3$-Design of experiment technique was applied and ADMAS was used for the surrogate technique. As a result, radial pivot position had more influence upon the nozzle actuating performance than axial pivot position. Connecting method of actuator was also important factor in determining effective-pivot effects on the thrust vector control performance of the flexible seal nozzle.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.141-146
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• 2002

During dynamic flight by propulsion of rocket engine, in the atmosphere, the attitude control of flight vehicle can be accomplished by the aerodynamic fin actuator. But, in the outer space, the method of TVC(Thrust Vector Control) is only depend on for it. There are many systems which were developed for TVC. In our research, among them we adopted gimbal engine actuation system which could control the vector of thrust by swivelling rocket engine connected by gimbal. There are electro-hydraulic, electro-mechanical and pneumatic system which can be used as gimbal engine actuation system, but the electro-hydraulic system that has high ratio of output power to mass is preferred for the high power system. In this note, we made a mathematical model of the electro-hydraulic gimbal engine actuation system for the TVC of KSR-III in detail and on the base of this model we performed a simulation study. And then, we verified the model by making a comparison between the simulation and the experiments on the real system.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.25-27
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• 1996

Instantaneous thrust control of linear induction motor(LIM) is needed to control its speed and position more accurately. In the vector control of LIM, it is hard to calculate flux angle exactly because of end effects of LIM. So in this paper direct vector control method is utilized to control speed of LIM. The airgap magnetic flux angle measured by hall sensors is transferred directly into coordinate transformer. As a result, some experimental values of direct vector control using DSP are shown.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.3
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• pp.59-66
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• 1998

In this paper, the thrust control of PWM Inverter-Fed SLIM(Single-sided Linear Induction Motor) is achieved with Space Vector control and PI control. The trembling of air gap length which is occurred between the primary winding core and the secondary structure of the SLIM must be minimized in order to get quick response characteristics. First, the equivalent circuits and voltage equations of SLIM are shown on th suitable d-q axis which analyze characteristics of the thrust and the normal force. Also, modeling and analysis of the equivalent circuits transferred d-q axis are able to make robust transient torque from the current regulation in the equivalent circuit. These results exemplified the direct drive of SLIM with the reference speed and torque were verified by experiments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.1
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• pp.35-42
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• 2020

Electromechanical Actuator(EMA) for flight vehicles generally serves to control the fin deflection angle or the thrust vector angle. This paper deals with design and development of EMA for both aerodynamic control and thrust vector control. In this paper, a novel compact EMA is proposed that can simultaneously control both the tail fin and the jet vane with one actuator and detach the jet vane after vertical launch and rapid turn of the flight vehicle so as to increase efficiency during flying to target. To do this, we designed the EMA using a push-push link mechanism and derived a mathematical model. The mathematical model is validated by comparing simulation result and experimental data. The performance and reliability of the proposed EMA have been verified through performance test, environmental test and ground test. The proposed EMA is expected to be useful as an EMA for flight vehicles because of its simple and compact structure, as well as its performance and reliability.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.170-176
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• 2008

The concept design of Flexible Seal for thrust vector control of solid motor was performed. Through the concept design, the optimum pivot point of flexible seal, cross-section configuration of flexible seal and thermal protection system from combustion gas was decided. The pivot point of flexible seal has aft pivot type and cross-section view is conical type. For satisfying a spring torque rate, the shear modulus of rubber has the value of under about 0.6MPa and failure shear stress has over about 2.5MPa.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.4
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• pp.12-24
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• 2020

The dual-throat nozzle is an extremely effective method in the thrust vectoring control field, utilizing another convergent section to connect with the divergent part of the conventional convergent-divergent nozzle. In the present research, the numerical simulation is conducted to investigate the effects of the injection angle on thrust vectoring performance in a 3D supersonic nozzle. Five injection angles are discussed and core performance variations are analyzed, including the deflection angle, injected mass flow ratio, system resultant thrust ratio, efficiency, Mach number contour and streamline on the symmetry plane, and Mach number contours at different slices. Meaningful conclusions are offered for fighter jet designers.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.723-730
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• 2014

Experimental study for supersonic co-flowing fluidic thrust vectoring control utilizing the secondary flow is performed. The characteristics of the thrust vectoring of two dimensional supersonic flow (Mach 2.0) are studied by Schlieren flow visualization and highly-accurate multi-component force measurements using the load cells. It is observed that the thrust deflection angle initially decreases and increases again forming a V-shaped variation as the pressure of the secondary flow increases. Characteristics of the performance coefficients of the system are also studied, and the detailed operating conditions for higher performance of the technique are suggested.