• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.2
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• pp.111-118
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• 2017

In this paper, combustion tests were performed to investigate performance characteristics of a canted slit-type pintle injector engine which uses kerosene and liquid oxygen as propellants. The number of slits, slit angle and blockage factor were chosen as design variables of the pintle injector. ${\Delta}SR$ was newly defined as the difference of skip ratio caused by both sides of the tip of the canted slit. The experimental results showed that optimal combustion was performed when the blockage factor is about 1 and the difference is less than 0.26.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.1038-1047
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• 2009

The development process of a gas generator for a 30-tonf pump-fed space liquid rocket engine is described. Starting from the development of an injector, followed by subscale and full-scale test specimens, the development of LOx/kerosene fuel-rich gas generator has been concluded successfully. Various analytical methods have been utilized in the course of design and the performance requirements have been verified experimentally through ignition tests, combustion performance and stability assessment tests and duration tests. The gas generator has proven its workability and stability within a defined operation window of varying chamber pressure and mixture ratio and demonstrated compliance to the performance and life time requirements.

• Fire Science and Engineering
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• v.32 no.1
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• pp.7-15
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• 2018

The prediction performance of combustion models in the Fire Dynamics Simulator (FDS) were evaluated by comparing with experiment for compartment propane gas fires. The mixture fraction model in the FDS v5.5.3 and Eddy Dissipation Concept (EDC) model in the FDS v6.6.3 were adopted in the simulations. Four chemical reaction mechanisms, such as 1-step Mixing Controlled, 2-step Mixing Controlled, 3-step Mixing Controlled and 3-step Mixed (Mixing Controlled + finite chemical reactions) reactions, were implemented in the EDC model. The simulation results with each combustion model showed similar level for the temperature inside the compartment. The prediction performance of FDS with each combustion model showed significant differences for the CO concentration while no distinguished differences were identified for the $O_2$ and $CO_2$ concentrations. The EDC 3-step Mixing Controlled largely over-predicted the CO concentration obtained by experiment and the mixture fraction model under-predicted the experiment slightly. The EDC 3-step Mixed showed the best prediction performance for the CO concentration and the EDC 2-step Mixing Controlled also predicted the CO concentration reasonably. The EDC 1-step Mixing Controlled significantly under-predict the experimental CO concentration when the previously suggested CO yield was adopted. The FDS simulation with the EDC 1-step Mixing Controlled showed difficulties in predicting the $CO_2$ concentration when the CO yield was modified to predict the CO concentration reasonably.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.318-321
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• 2005

The design and performance test of a low NOx gas turbine combustor to be used in 55kW class micro-gasturbine engine was performed in KARI's combustion test facility. The combustor is reverse flow-can type for easy installation of injector and other parts and LNG is used as fuel. The performance targets are $99.5\%$ combustion efficiency, less 10ppm NOx, $30\%$ patten factor and $4\%$ pressure loss. Most of the performances required are satisfied.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.173-178
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• 2003

The study was performed to understand combustion characteristics of the slinger combustor. Liquid fuel is discharged radially outwards through injection holes drilled in the high speed rotating shaft. We observed atomizing characteristics with variation of fuel nozzle rotating speed by using PDPA system. The mean drop diameter highly depends on fuel nozzle rotating speed. In KARI combustion test facility, Ignition and combustion tests were performed by using real scale combustor. In the test results, ignition and combustion efficiency were increased according to increasing fuel nozzle rotating speed. The measured radial temperature distribution at the combustor exit shows stable and fairly good distribution.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.56-61
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• 2014

Two erosive burning models were applied to compare analysis results of ballistic for the internal ballistics of solid rocket motors. By comparing motor tests with results of analysis, the variance of a grain shape was analyzed and coefficients of erosive burning were drawn. Results of comparison presents that the coefficient of erosive burning was proportional to the change of burning area, while inversely proportional to the change of cross area.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.258-261
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• 2003

The optimal design and combustion analysis of the gas generator for Liquid Rocket Engine (LRE) were performed. A fuel-rich gas generator in open cycle turbopump system was designed for 101on1 in thrust with RP-1/LOx combination. The optimal design was done for maximizing specific impulse of main combustion chamber with constraints of combustion temperature and power matching in turbopump system. Results of optimal design show the dimension of length, diameter, and contraction ratio of gas generator. The configuration of the gas generator and the condition for performance which can maximize the objective function were determined and found to meet the design constraints. Also, the combustion analysis was conducted to evaluate the performance of designed chamber and injector of gas generator. And the effect of the turbulence ring was investigated on the mixing enhancement in the chamber.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.55-62
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• 2011

In this study, we tried to improve the thrust control performance through the thrust control combustion experiment of the hybrid rocket. We constructed the system which controls the oxidizer flow by combining a needle valve with a stepping motor and controlling the stepping motor drive according to the thrust control command order. Gas oxygen was used as the oxidizer for two different propellants, PE(Polyethylene), PC(Polycarbonate), respectively. To improve the slow response time and the oscillation phenomenon in the beginning stage of the thrust control combustion experiment, we measured and analyzed the change of the flow speed of the propellant pipe. The revised thrust control combustion experiment showed that the thrust was stably controlled with the margin or error from the thrust command within ${\pm}1$ N.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.3
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• pp.67-75
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• 2013

The numerical analysis for the verification of preburner's cooling characteristics applying to kerosene-LOx rocket engine has been fulfilled. The distribution of combustion gas properties in primary combustion zone was calculated by the mixture ratio based on head injector arrangement, the properties of oxygen flowing in wall channels as coolant were applied under real-gas conditions, and multi-phase mixing model was employed to calculate the mixing process of primary combustion zone with liquid oxygen which was used for wall cooling. The results of numerical analysis were compared with the experimental results, hence thermo-physical properties in cooling channels and a combustor could be quantitatively identified.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2009.04a
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• pp.229-234
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• 2009

본 연구에서는 친환경 인테리어용으로 개발된 벽포지에 대해 방염성능이 시험되었다. 실제로 방염성능은 "45$^{\circ}$ 연소시험" 및 "접염시험", 그리고 "연기밀도시험"에 의해서 수행되었다. 벽포지의 주성분이 고온에서 쉽게 용융하는 PET(폴리에스터) 이다. PET의 이런 물성으로 인하여 "45$^{\circ}$ 연소시험"과 "연기밀도시험"의 요구조건들은 쉽게 만족시킬 수 있었지만, 용융 물품에 대해 추가로 요구되는 "접염시험"은 통과하기 어려웠다. 총 47종 109점에 대해 방염성능시험을 수행한 결과 18종 54점이 요구조건을 만족하였다. 일반적으로 보드에 배접된 상태로 시공되는 모듈의 난연성능을 개선하기 위해서는 벽포지의 방염성능뿐만 아니라 보드, 접착제 등의 특성에 관한 보다 많은 연구가 필요하다.