• 한국수소및신에너지학회논문집
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• 제20권4호
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• pp.344-351
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• 2009

A multi-zone model was used to predict the operating range of homogeneous charge compression ignition (HCCI) engine, the boundaries of the operating range were determined by knock (presented by ring intensity), misfire (presented by sensitivity of indicated mean effective pressure to the initial temperature). A HCCI engine fueled with Di-Methyl Ether (DME) was simulated under different initial temperature and equivalence ratios, and the operating range was well produced by the model. Furthermore, the model was applied to develop the operating range for thermal stratification in the preceding condition of initial temperature and equivalence ratios. The computations were conducted using Senkin application of the CHEMKINII kinetics rate code.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.62-68
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• 2004

A comprehensive numerical analysis has been carried out for both non-reacting and reacting flows in a scramjet engine combustor with and without a cavity. The theoretical formulation treats the complete conservation equations of chemically reacting flows with finite-rate chemistry of hydrogen-air. Turbulence closure is achieved by means of a k-$\omega$ two-equation model. The governing equations are discretized using a MUSCL-type TVD scheme, and temporally integrated by a second-order accurate implicit scheme. Transverse injection of hydrogen is considered over a broad range of injection pressure. The corresponding equivalence ratio of the overall fuel/air mixture ranges from 0.167 to 0.50. The work features detailed resolution of the flow and flame dynamics in the combustor, which was not typically available in most of the previous studies. In particular, the oscillatory flow characteristics are captured at a scale sufficient to identify the .underlying physical mechanisms. Much of the flow unsteadiness is related not only to the cavity, but also to the intrinsic unsteadiness in the flow-field. The interactions between the unsteady flow and flame evolution may cause a large excursion of flow oscillation. The roles of the cavity, injection pressure, and heat release in determining the flow dynamics are examined systematically.

• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.758-766
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• 2023

Multi-copter of unmanned aerial vehicle (UAV) was initially developed as strategic technology in the only military field, but it is developing into an industrial field with a wide range of applications in the civil sector based on the development and convergence of aviation technology and information and communication technology. Currently, the degree of utilization of multi-copter is increasing in various industries for the purpose of performing classic tactical missions, logistics transportation, farm management, internet supply, video filming, weather management, life-saving, etc, and active technology development responding to market demand. Existing commercial multi-copter mainly use an electric energy propulsion system consisting of an electric battery and a brushless direct current (BLDC) motor. It is the limitations for usage in the flying time (up to 20 minutes) and payload (less than 20 kg). this study aims to overcome these limitations and expand the commercialization of engine-powered multi-copter of UAV in various industries in the futures.

• 한국수소및신에너지학회논문집
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• 제8권1호
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• pp.5-10
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• 1997

Because of environmental pollution and reserve limitations of fossil fuels, several alternative energies have been developing. One of them, the hydrogen is researched as a highly probable solution. In this study pure hydrogen gas and oxygen gas are burned in combustor to reduce the emission, and a gas turbine is used. Cooling water around the combustor recovers the cooling heat loss to useful work by being expanded from liquid to vapor, being injected into the combustor and making pressure rise with working fluid to get more turbine power. Because pure hydrogen and oxygen are used, there is no carbonic emission such as CO, $CO_2$, HC nor $NO_x$, and $SO_x$. The power is obtained by turbine system, which makes lower noise and vibration than any reciprocating engine. Running of a turbine is searched under various conditions of hydrogen flow rate and water injection rate. Maximum speed of the turbine is obtained when the combustion reaches steady state. It is enable to determine the optimum rate between hydrogen flow and water injection which makes turbine run maximum speed.

• 한국가스학회지
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• 제13권4호
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• pp.46-52
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• 2009

고유가 시대의 도래와 강화되는 배출가스 규제에 대응하기 위한 대책으로 대체에너지 엔진 및 수소연료전지와 같은 새로운 연소 및 동력 기술에 대한 관심이 증대되고 있으나, 이러한 기술의 이용은 수소제조 및 공급 기반시설 구축이 선결되어야 하며 많은 투자가 요구된다. 수소를 내연기관에 활용하는 기술은 연료의 저장과 공급, 낮은 에너지 밀도 및 연소제어 등의 어려움이 있다. 그러나 화석연료로부터 합성연료를 제조하기 위한 중간단계로 생성되는 개질가스의 이용은 내연기관으로의 실시간 수소 공급을 가능하게 하고, 소량의 수소가 혼합연료 형태로 사용됨에 따라 연소특성을 향상시킬 수 있다. 본 연구에서는 다양한 연료들의 개질 특성을 이해함과 동시에 연료 개질기의 적용가능성 여부를 판단하고자 하였다. 연료별 최대의 수소수율을 얻을 수 있는 조건에서의 열역학적 개질효율과 수소수율을 관찰하였으며, 연료와 산화제의 촉매상에서의 체류시간에 대한 영향 및 연료/산화제 비율에 변화 시 최대 수소 수율을 제시하였다.

• 한국수소및신에너지학회논문집
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• 제23권2호
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• pp.183-190
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• 2012

The research shows the experiment results according to the combustion characteristics and configuration of the linear generator of powerpack for the generating power applying the 2-stroke compact linear engine. The powerpack used in this paper consists of 2-stroke linear engine, linear generator and air compressor parts. For identifying the combustion characteristics and generating power of linear engine, some parameters were varied sucha as electric load, fuel input calorie, spark timing delay and equivalence ratio. Also generating power was confirmed at each operation conditions, when the air gap length of linear generator part was changed as each 1.0 mm and 2.0 mm. During the all operations, intake air was inputted under the wide open throttle. Mass flow rate of air and fuel was changed using mass flow controller, after these were premixed by premixture device, and then premixed gas was supplied directly into each cylinder. As a result, piston frequency and combustion characteristics were different at each conditions according to parameters affecting the combustion such as fuel input calorie, resistive load, spark timing delay and equivalence ratio. Consequently, these had an effect on generating power.

• 드라이브 ㆍ 컨트롤
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• 제20권4호
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• pp.151-154
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• 2023

• 드라이브 ㆍ 컨트롤
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• 제20권4호
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• pp.155-156
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• 2023

• 한국추진공학회지
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• 제14권6호
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• pp.69-78
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• 2010

고농도 과산화수소를 이용하는 1,200 N 급 이원추진제 로켓 엔진 개발을 위한 선행 연구의 일환으로 이원추진제 엔진 요소를 설계하고 실험적으로 연구하였다. 공급된 과산화수소의 분해 성능을 비교하기 위해, $MnO_2$와 Pb가 첨가된 $MnO_2$ 촉매들에 대한 실험을 하였다. 실험결과를 바탕으로, 촉매 반응기를 설계하였으며, 97.2%의 분해 효율을 얻었다. 별도의 점화원이 없이 자연점화를 이용하기 위해, 다양한 당량비에 대해 자연점화 실험을 수행하였다. 모든 실험조건에서 자연 점화를 확인하였으며, $C^*$ 효율은 90% 혹은 그 이상을 보였다. 추력측정 결과, 가장 높은 추력은 830 N을 보였으며, $C^*$ 효율과 $I_{sp}$ 효율을 같다고 가정했을 때, 진공 추력 1,035 N으로 계산되었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.156-164
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• 2010

고농도 과산화수소를 이용하는 1,200 N 급 이원추진제 로켓 엔진 개발을 위한 선행 연구의 일환으로 이원추진제 엔진 요소를 설계하고 실험적으로 연구하였다. 공급된 과산화수소의 분해 성능을 비교하기 위해, $MnO_2$와 Pb가 첨가된 $MnO_2$ 촉매들에 대한 실험을 하였다. 실험결과를 바탕으로, 촉매 반응기를 설계하였으며, 97.2%의 분해 효율을 얻었다. 별도의 점화원이 없이 자연점화를 이용하기 위해, 다양한 당량비에 대해 자연점화 실험을 수행하였다. 모든 실험조건에서 자연 점화를 확인하였으며, $C^*$ 효율은 90% 혹은 그 이상을 보였다. 추력측정 결과, 가장 높은 추력은 830 N을 보였으며, 94.1% 이론 비추력을 적용했을 경우, 진공 추력 1,035 N으로 계산되었다.