• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.24-30
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• 2013

To guarantee the exact control of missile warhead, it is inevitable to ensure the stabilities in the view points of structural and fluid/thermo dynamics of the rocket motor. Specially, despite of shortness in operating time of the rocket motor which is initial turning type of missile, it occurs frequently some problems of ablation at the neighborhood of the nozzle throat, with the result that the system itself gets to failure. In these connections, in the present study, the effect of the operating time of a rocket motor on the coefficient of convective heat transfer at the nozzle wall is investigated by numerical analysis. As a result, it is turned out that the heat transfer coefficient is largest at the just ahead of nozzle throat and decreases with the increase of operating time of the rocket motor. Furthermore, we found that the radius of curvature of throat becomes smaller, the maximum coefficient of convective heat transfer becomes larger.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.6
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• pp.82-87
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• 2014

Dual pulse rocket motor has a rocket motor with different pulse grains divided by a pulse separation device such as a fragile bulkhead or a thermal barrier type. It distributes thrust energy very effectively via pulse separation device to improve range and terminal velocity of a missile. This paper contains the thermal barrier design and experimental analysis through ground firing tests of small dual pulse motors. The results will be applied to the design, test and evaluation of the scale up dual pulse rocket motor.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.3
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• pp.69-76
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• 2012

An achieving method of highly progressive pressure gradient is presented to enhance the missile ejection system's performance by using a gas generator in the condition of preventing erosive burning. To obtain and confirm a stable burning, a ground burning test was performed to evaluate the new methods of a radial-hole and a multi-row propellant grain. The test results show that a radial-hole grain takes good effect on erosive burning and not on ejection performance. On the other hand, a multi-row grain which reduces the length-to-diameter ratio(L/D) of grain is very effective to prevent the erosive burning and to enhance the ejection performance simultaneously.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.369-374
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• 2011

To solve the combustion instability, especially chuffing phenomena, happened during development process of the drive-away motor that was required for cold launch system of missile, we tried various technical approaches and performed ground firing tests. The supplying content or method of ignition energy, generally that is deeply related with the chuffing phenomena, does not affect suppression of the chuffing, but the addition of 2% ZrC as a damping material is effective to suppress the chuffing. Therefore we could newly experience a special solution of the combustion instability in double base propellant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.432-439
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• 2011

An achieving method of highly progressive pressure gradient is presented to enhance the missile ejection system's performance by using a gas generator in the condition of preventing erosive burning. To obtain and confirm a stable burning, a ground burning test was performed to evaluate the new methods of a radial-hole and a multi-row propellant grain. The test results show that a radial-hole grain takes good effect on erosive burning and not on ejection performance. On the other hand, a multi-row grain which reduces the legnth-to-diameter ratio(L/D) of grain is very effective to prevent the erosive burning and to enhance the ejection performance simultaneously.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.4
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• pp.112-120
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• 2005

The solid propellants have been most widely used for the military rockets or missiles all over the world and the efforts have been focused on the enhancement of propellant performance up to 1980s. lately in company with the distinguished development in the intelligence and communication technology, the more accurate guidance as well as maneuverability has been required in the military weapon system. To meet the requirements such as a high maneuverability, insensitiveness, or stealth of missile, the researches have been doing to develop the solid propellants which have a quality of ultra-fast burning rate, insensitiveness, low signature or the like.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.4
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• pp.39-45
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• 2003

Of the various means for active trajectory correction, a thrust vector control system represents the only principle independent of missile external forces so that this method is operative. The purpose of this study is to analyze the characteristic of jet vane TVC(Thrust vector control) system among mechanical jet deflection. To ensure high performance leading edge shape, aspect ratio and ablated condition is optimized. Supersonic flow system, jet vanes and nozzle with Mach number 2.88 and under expansion ratio 2 were designed to study aerodynamic characteristics of leading edge shape, aspect ratio and ablated conditions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.335-338
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• 2007

In the case of an antiaircraft missile, high angle of attack flight capability is required to get the agile maneuverability in a supersonic flow. Even through a symmetric slender body does not have side slip, asymmetric vortex is generated at high angle of attack conditions. This asymmetric vortex produces unnecessary side force and yawing moment; hence, these effects deteriorate directional stability. In this study, the numerical analysis of asymmetric vortices around the slender body was conducted at high angle of attack supersonic flow. In order to simulate the vortices, a bump is installed on the nose of the slender body. As a result of the numerical analysis, the asymmetric vortices around the slender body could be simulated.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.6
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• pp.62-72
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• 2012

Divert and attitude control system(DACS) plays an important role for orbit transfer and attitude control, and therefore becomes important subject for recent space vehicle and Precision Guided Missile(PGM) development. To develop DACS system, main research areas include shape combination of pintle and nozzle to maximize thrust change, and reduction of aerodynamic pintle load to minimizle pintle driving force, and development of multi-axis control algorithm. In this paper, introduction, classification, and overseas/domestic research and development program, and prospects of DACS are reviewed and summarized.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.548-551
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• 2010

A 150 lbf-thrust class micro turbojet engine has been developed. The engine could be applied to power plant for small aviation vehicle such as UAV, decoy and anti-radar missile and was designed with concepts that has small size, low-cost and high performance. A prototype was manufactured and performed the ground static test and high altitude test. This paper outlines the features and layout of 150 lbf turbojet engine and also describes the design characteristics and test results of the engine and components.