• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.283-291
• /
• 2011

A computational investigation has been carried out to study the heat transfer characteristics of jet vane assembly used for the thrust vector control(TVC) of a vertical launch motor. In this study, the coefficients of convective heat transfer on the jet vane are calculated using the solutions of thermal boundary-layer equation and several semi-empirical equations. The calculation of 3-dimensional temperature distribution for the jet vane assembly was performed using the softwares called PATRAN and ABAQUS. The accuracy of the present numerical method is verified by comparing with the measured and calculated temperatures within jet vane shaft. The temporal variation of jet vane temperatures for three deflection angles(0o, 12.5o, 25o) was discussed.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.119-122
• /
• 2002

In general, Liquid Injection Thrust Vector Control(LITVC) is accomplished by injecting a liquid into the supersonic exhaust flow through holes in the wall of the propulsion nozzle. This injection flow field is highly complicated and detailed flow physics associated with the secondary flow injection should be known far the practical design and use of the LITVC system. The present study aims at understanding the LTTVC flow field and obtaining fundamental design parameters for LITVC. The experimentations were performed in a supersonic blow-down wind tunnel. Compressed, dry air was used for both the main exhaust and injection flows but the pressures of these two flows were controlled independently. The location of the injection holes was changed and the pressures of the two streams were also changed between 2.0 and 15.0 bar. The effectiveness of LITVC was discussed in details using the results of the pressure measurements and flow visualizations

• Journal of the Korean Society of Propulsion Engineers
• /
• v.9 no.4
• /
• pp.73-80
• /
• 2005

In general, the performance of movable nozzle used for thrust vector control in solid rocket motor is estimated on the basis of the effective pivot of nozzle. However, it is nearly impossible to define the exact effective pivot by the mathematical model or experimental technique owing to pivot dynamics. In this paper, pivot dynamic properties were investigated by ADAMS simulation technique and trajectory of the exact effective pivot was modelled by the artificial neural network. Comparison of the proposed method was made with the virtual movable nozzle (computer simulation) to verify the method, and showed good agreement. Therefore, the proposed method will be applicable to predict the effective pivot of movable nozzle during bench or ground test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.404-407
• /
• 2011

The fluidic thrust vector control using co-flowing coanda effect of secondary jet at the nozzle exit is a new concept for efficient thrust vectoring of supersonic jet exhausts. Flow visualization of the flow fields in previous studies have shown some pros and cons of the technique, however, most of the observations were somewhat limited as qualitative data. The present study was designed to evaluate the quantitative performance-characteristics of the thrust-vectoring technique utilizing coanda effects of the secondary jet. Details of design of the test device and calibration/data reduction procedure are provided.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.24 no.1
• /
• pp.34-46
• /
• 2020

Computational assessment of gas-dynamic characteristics is explored for a three-dimensional counter-flow thrust vector control system in a rectangular supersonic nozzle. This convergent-divergent nozzle is designed by Method of Characteristics and its design Mach number is specially set as 2.5. Performance variations of the counter-flow vector system are illustrated by varying the gap height of the secondary flow duct. Key parameters are quantitatively analyzed, such as static pressure distribution along the centerline of the upper suction collar, deflection angle, secondary mass flow ratio, and resultant thrust coefficient. Additionally, the streamline on the symmetry plane, three-dimensional iso-Mach number surface contour, and three-dimensional turbulent kinetic energy contour are presented to reveal overall flow-field characteristics in detail.

• Journal of Electrical Engineering and Technology
• /
• v.2 no.2
• /
• pp.221-230
• /
• 2007

This paper deals with analytical prediction for electromagnetic characteristics of a tubular linear actuator with Halbach array using transfer relations, namely, Melcher's methodology. Using transfer relations derived in terms of magnetic vector potential and a two-dimensional (2-d) cylindrical coordinate system, this paper derives analytical solutions for magnetic vector potential due to permanent magnets (PMs) and stator winding currents. On the basis of these analytical solutions, this paper also achieves analytical solutions for the magnetic fields distribution produced by PMs, stator windings current and axial thrust. The analytical results are validated extensively by finite element (FE) analyses. In particular, test results such as thrust measurements are given to confirm the analysis. Finally, this paper estimates control parameters using analytical solutions and test results such as thrust, back-emf, inductance and resistance measurements.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.16 no.2
• /
• pp.34-41
• /
• 2012

Thrust vector control system is a control device which is mounted on the exit of the nozzle to generate pitch, yaw and roll directional force by deflecting flow direction of the supersonic jet from the nozzle. Thermal and aerodynamic loads are acting on the surface of jet vane when it is exposed to the jet flow. Axial thrust loss and side thrust loss are affected by shock patterns and interactions between jet-vanes which varies with jet-vane geometry and turning angle. In this research, the performance estimation using the numerical simulation analysis of the nozzle is given and the investigation of the flow visualization and aerodynamic performance with the enforced power to the vane is taken.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.10a
• /
• pp.109-112
• /
• 2004

Of late, the thrust vectoring control, using fluidic co-flow and counter-flow concepts, has been received much attention since it not only improves the maneuverability of propulsive engine but also reduces an additional material load due to the trailing control wings, which in turn reduce the aerodynamic drag. However, the control effects are not understood well since the flow field involves very complicated non: physics such as shock wave/boundary layer interaction, separation and significant unsteadiness. Existing data are not enough to achieve the effectiveness and usefulness of the thrust vectoring control, and systematic work is required for the purpose of practical applications In the present study, computational study has been performed to investigate the effects of the thrust vector control using the fluidic co-and counter-flow concepts. The results obtained show that, for a given pressure ratio, the thrust deflection angle has a maximum value at a certain suction flow rate, which is at less than $5\%$ of the mass flow rate of the primary jet. With a longer collar, the same vector angle is achievable with smaller mass flow rate.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.11a
• /
• pp.613-615
• /
• 2009

This paper is to introduce Hanwha Aerospace R&D Center's development status of TVC(Thrust Vector Control) system and control valves for Korean space launch vehicles. With the successful development of KSR-III TVC system, Hanwha have developed TVC system and RCS control valves for KSLV-I. Also, in the advance research area of KSLV-II, Hanwha have participated in LOx and fuel flow control valves and LOx shut-off valve development in the engine supply system. Based on the accumulated experiences and technologies in the aerospace key components and system development, Hanwha will make an important contribution to KSLV-II development in the future.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.116-121
• /
• 2011

Performance of Secondary Injection Thrust Vector Control system is investigated under various secondary injection operating conditions. 3-dimensional converging-diverging nozzle having 8 secondary injection nozzles is used in this numerical study. Total pressure of flow inside the nozzle is about 70bars, and total temperature set to 300K for cold flow simulation. Effect of secondary injection flow rate and injection nozzle configuration is considered in this research. Simulation is conducted with commercial CFD code Ansys Fluent v13. Spalart-Allmaras(1-equation)model is used for turbulence modeling with AUSM+ scheme. Various performance factors as Axial thrust, side force, system specific impulse ratio are considered and explained for system performance evaluation.