• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.47-53
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• 2015

Design parameters required for Methane/oxygen bipropellant small-rocket-engine were derived through a theoretical performance analysis. The theoretical performance of the rocket engine was analyzed by using CEA and optimal propellant mixture ratio, characteristic length, and optimal expansion ratio were calculated by assuming chemical equilibrium. A coaxial-type swirl injector was chosen because of its outstanding atomization performance and high combustion efficiency compared to other types of injector and also a bell nozzle with 80% of its full length was designed. The rocket engine configuration with 1.72 MPa of chamber pressure, 0.18 kg/s in total propellant mass flow, and O/F ratio of 2.7 was proposed as a ground-firing test model.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.04a
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• pp.90-90
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• 2001

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.11a
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• pp.19-19
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• 2000

가스 터빈 엔진의 주요 구성품의 하나인 압축기는 입구 유동 조건의 변화에 따른 성능 변화가 민감하므로 엔진 성능 예측 시 압축기 성능은 매우 중요한 요소라 할 수 있다. 압축기 내의 유동은 본질적으로 비정상 유동이며 역압력 구배에서 작동하는 점에서 해석이 어려운 것으로 알려져 있지만 최근 컴퓨터의 비약적인 발전에 힘입어 전산유체역학(CFD)을 이용한 압축기 익렬 유동해석에 관한 연구가 활발히 진행되고 있다. 그러나 이러한 연구는 설계 점 주위의 조건, 즉 압축기 익렬에 대한 입사각이 그다지 크지 않은 경우에 대한 것이 거의 대부분이다.(중략)

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.1-8
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• 2010

In this paper, we present some results of technical surveys, power analyses, and weight estimation on electric propulsion systems for 1-ton class Personal Air Vehicles(PAV) applications. When hybrid electric propulsion is adopted, its power performance using fuel cells and batteries in inferior to that of internal combustion engines. However, hybrid electric propulsion systems may replace IC engines when energy density and power density reach 0.75 kW$^*$hr/kg and 2.5 kW/kg, respectively.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.71-78
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• 2019

This paper describes the formulation and properties of a recently developed energetic thermoplastic (ETPE) propellant, which is composed of 45% of newly synthesized glycidyl azide polymer, energetic plasticizer (DEGDN) and nitramine oxidizer (RDX). Compared to conventional thermoplastic propellants, the new ETPE propellant showed approximately 7% higher performance and exhibited similar mechanical properties but a lower burn rate and a higher pressure exponent.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.1
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• pp.77-83
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• 2021

In the current study, the numerical method was established to predict the performance of a solid rocket motor with two kinds of propellants. On the basis of a numerical study, an internal ballistics analysis code was developed. To verify the internal ballistics analysis code two solid rocket motors were manufactured and tested. The accuracy and applicability of the internal ballistics code for dual-propellant solid rocket motor were verified by comparing the experimental results with the numerical calculation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.281-284
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• 2006

An intelligent performance diagnostic program using the Neural Network was proposed for PW206C turboshaft engine. It was selected as a power plant for the tilt rotor type Smart UAV (Unmanned Aerial Vehicle) which has been developed by KARI (Korea Aerospace Research Institute). The measurement parameters of Smart UAV propulsion system are gas generator rotational speed, power turbine rotational speed, exhaust gas temperature and torque. But two measurement such as compressor exit pressure and compressor turbine exit temperature were added because they were difficult each component diagnostics using the default measurement parameter. The performance parameters for the estimate of component performance degradation degree are flow capacities and efficiencies for compressor, compressor turbine and power turbine. Database for network learning and test was constructed using a gas turbine performance simulation program. From application results for diagnostics of the PW206C turboshaft engine using the learned networks, it was confirmed that the proposed diagnostics could detect well the single fault types such as compressor fouling and compressor turbine erosion.

• Journal of Sensor Science and Technology
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• v.12 no.4
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• pp.170-175
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• 2003

The korean high speed train(350km/h), composed of 7cars that are 2 power cars, 2 motorized car and 3 trailer cars, has been developed and is under on-line test. To verify the design requirements about the functions and traction performances of this train, KRRI(Korea Railroad Research Institute) decided to evaluate traction performances of the train during on-line test. For this purpose, such as torque, velocity, voltage and current, must be measured. KRRI has developed the measurement system that can be measured vast and various signals effectively. In this paper, we introduce traction performances of korean high speed train. The traction measurement items are focused on the verification of motor block performances. Motor block are consist of 2 motor. For this test, we verified traction performances of korean high speed train.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.717-728
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• 2009

In the field of rocket propulsion system hydrogen peroxide has been used as mono-propellant and as the oxidizer of bi-propellants. At the beginning, hydrogen peroxide was used as mono-propellant for thrusters, but later it had been replaced by hydrazine, which has better specific impulse and storability. On the other hand, to drive turbo-pumps, hydrogen peroxide is still being utilized. As the oxidizer of bi-propellants it was used until 1970's and from 1990's hydrogen peroxide once again got back to developer's interest, because one of the recent development purposes of rocket propulsion system is low-cost and ecologically-clean. Until now the storability of hydrogen peroxide has been remarkably improved. The combination of Kerosene/$H_2O_2$ also shows similar accelerating performance to Kerosene/$LO_x$ combination because of higher propellant density and higher O/F ratio, even though the propulsion performance is not as good as the combination of Kerosene/$LO_x$. Moreover, its combustion products are much cleaner than Kerosene/$LO_x$ combination.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.11a
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• pp.22-22
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• 2000

고체 추진제에서 연소실 압력이 급격히 변하는 비정상 상태에서의 연소 특성은 정상 상태와 다른 경향을 보인다. 고체 추진 시스템에서 안정적이고 필요한 성능을 얻기 위해서는 이러한 비정상 상태에서 일어나는 현상에 대한 예측이 필요하다. 고체 추진제에서 비정상 연소는 크게 두 가지 경우에 나타나게 된다. 그 중 하나는 소염을 위하여 연소실내 압력강하가 일어나는 경우이며, 다른 하나는 점화 후 압력이 상승하는 경우이다. 급격한 압력 강하로 인한 고체 추진제의 소염에 대하여 그 동안 많은 연구들이 진행되었다.(중략)