• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.232-235
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• 2011

A typical unsteady internal ballistic analysis model was developed to take account the erosive burning of a solid rocket motor. The variance of local velocity and pressure along grain surface were analyzed by using the continuity and momentum equation. The coefficients of erosive burning were drew from comparing experiment data with analysis. It was investigated that the grain shapes of propellant affect the erosive burning.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.48-55
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• 2014

In present study, design and hot fire tests of the pryostarter are conducted. To prevent the turbopump RPM overshoot, regressive mass flow rate profile is applied. Sudden decrease of the mass flow rate at the end of the propellant burning is realized as well. Firing test results show good agreements with the design requirements. Through the study with ignition substance variations, combustion products and ignition performances are improved.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.968-971
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• 2017

In this study, manufacturing the Single Base propellant using a Nitroguanidine(NGD A%, NGD-B%, 2A=B). The Factors affecting the combustion rate are Moisture and Volatiles, Residual Solvents, Dimension. These Factors were analyzed and compared. Also, NGD-A% propellants and NGD-B% propellants were compared with firing test Test. As a result, NGD-A% was confirmed to have a higher speed at a similar pressure than NGD-B% propellants.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.8
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• pp.95-103
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• 2006

The compositions, the gas properties in motor chamber and the aluminum oxide (Al2O3) particle size for two kinds of solid propellants with approximately 20% aluminum powder have been investigated. The SEM photographs of $Al_2O_3$ taken from nozzle entrance liner show that the aluminized PCP propellant with 47% volumetric fraction AP/HNIW and bimodal oxidizer 200-5 ${\mu}m$ can offer greater possibility for increasing aluminum agglomeration than the aluminized HTPB propellant with 64% volumetric fraction AP and trimodal oxidizer 400-200-6 ${\mu}m$. The nozzle entrance liner of solid rocket motor with the PCP propellant shows greater erosion at 4 circumferential sections in line with grain slots due to the impingement of large particles, but that with the HTPB propellant shows uniform erosion with circumferential angle.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.4
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• pp.48-56
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• 2011

A Possibility of combustion instability on longitudinal mode has a high level at large scale of L/D. Solid propellant has a metal particle and a grain of control to pressure oscillation. Solid rocket motor in slotted-tube grain controls pressure oscillation of longitudinal mode. Slotted-tube grain restrains longitudinal 1st pressure oscillation. But cavity volume of aft. insulation ablation amplifies 2nd pressure o scillation by vortext shedding. A study has suppressed combustion instability and vortex shedding by modified 4 slotted tube solid rocket motor design.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.293-300
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• 2008

Efficient designing of SRM Grains in the field of Rocketry is still the main test for most of the nations of world for scientific studies, commercial and military applications. There is a strong need to enhance thrust, improve the effectiveness of SRM and reduce mass of motor and burning time so as to allow the general design to increase the weight of payload/on board electronics. Moreover burning time can be increased while keeping the weight of the propellant and thrust in desired range, so as to give the time to control / general design group in active phase for incorporating delayed cut off if required. A mathematical design, optimization & analysis technique for Slotted Tube Grain has been discussed in this paper. In order to avoid the uncertainties that whether the Slotted Tube grain configuration being designed is best suited for achieving the set design goals and optimal of all the available designs or not, an efficient technique for designing SRM Grain and then getting optimal solution is must. The research work proposed herein addresses and emphasizes a design methodology to design and optimize Slotted Tube Grain considering particular test cases for which the design objectives and constraints have been given. In depth study of the optimized solution have been conducted thereby affects of all the independent parametric design variables on optimal solution & design objectives have been examined and analyzed in detail. In doing so, the design objectives and constraints have been set, geometric parameters of slotted tube grain have been identified, performance prediction parameters have been calculated, thereafter preliminary designs completed and finally optimal design reached. A Software has been developed in MATLAB for designing and optimization of Slotted Tube grains.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.5
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• pp.35-43
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• 2022

Precise modeling and analysis of closed bomb test(CBT) combustion using solid propellants was performed. The fluid structure interaction(FSI) method was implemented to analyze the gas and solid phases at the same time. The Eulerian analysis method was applied for the gas phase and grain combustion, and the Lagrangian analysis method was implemented for the grain movement. The interaction between the solid phase grains and the combustion gas was fully coupled through the source term. The volume of fluid(VOF) method was used to simulate the burning distance of the grain and the movement of the combustion surface. The force acting on the grain was comprised of the pressure and gravity acting on the grain burning surface, and the grain burning rate and grain movement speed were considered in the velocity term of the VOF. The combustion analysis was performed for both one and three grains, and fairly compared with the experiments. The acoustic field during grain combustion due to pressure fluctuations was also analyzed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.374-377
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• 2007

본 보고서는 소형 로켓 제작에 앞서 행해지는 설계 단계를 기술하였다. 각 요구 조건에 맞춰 사용되어질 추력, 추진제 특성, mass distribution, 동체 형상 설계, Motor 설계에 대해 다뤘다. 로켓 설계에 있어서 가장 중요한 추진제 선정과 노즐형상 설계를 중점적으로 다루었으며, 차후 본 과정에 의하여 소형로켓을 제작하겠다.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.4
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• pp.81-91
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• 2019

The 3-dimensional grain burn-back analysis is performed using the face offsetting method for calculating the solid rocket motor performance. The grain burning configuration analysis is a moving surface problem that calculates the regression of the burning surface. In the previous study, various moving interface analysis methods were applied for the grain burn-back analysis, but the results were imperfect. In this study, a 3-dimensional grain burn-back analysis module is developed using the face offsetting method, which combines the advantages of the existing moving interface analysis methods to increase the accuracy and robustness. As a result, the face offsetting method is proved to be efficient for the grain burn-back analysis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.32-32
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• 1998

고체 로켓 모타 추진제 그레인은 크게 단면 연소형 그레인(end-burning grain)과 내면 연소성 그레인(perforated grain)으로 분류할 수 있다. 단면 연소형 그레인은 부피충전율이 크고 구조적 안전성이 우수한 장점이 있으나 연소면적이 작은 단점이 있고, 내면 연소형 그레인은 연소면적이 큰 장점이 있으나 부피 충전율이 작은 단점이 있다. 따라서 단면 연소형 그레인의 장점인 높은 충전율을 유지하면서 연소면적을 증대시키는 효율적인 방법으로 열전도율이 높은 금속선을 단면 연소 그레인에 삽입시키는 방법이 있다. 높은 열전도율로 인하여 금속선을 따라 연소속도가 빨라져 연소면적이 증가하게 되는데, 금속선이 없을 때의 연소속도와의 비를 연소속도 증가 비라 한다. 이는 추진제 종류, 금속선 재질, 굵기 등에 따라 달라지고, 실험실에서 strand burner test로 구할 수 있다.