• 제목/요약/키워드: engine performance

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소형 장기체공 무인기용 왕복엔진 성능 예측 시뮬레이션 연구 (A Study on Performance Simulation of an Reciprocating Engine for Small Long Endurance Unmanned Aerial Vehicles)

  • 장성호;구삼옥;신영기
    • 대한기계학회논문집B
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    • 제29권7호
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    • pp.820-827
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    • 2005
  • Development of an engine with good fuel economy is very important for successful implementation of long endurance miniature UAVs (unmanned aerial vehicles). In the study, a 4-stroke glow-plug engine was modified to a gasoline-fueled spark-ignition engine. Engine tests measuring performance and friction losses were conducted to tune a simulation program for performance prediction. It has been found that excessive friction losses are caused by insufficient lubrication at high speeds. The simulation program predicts that engine power and fuel economy get worse with high altitude due to increasing portion of friction losses. The simulation results suggest quantitative guidelines for further development of a practical engine.

천연가스 전소엔진과 가솔린엔진의 성능과 배출가스 특성비교 (The Comparison of Performance and Emission Characteristics between CNG Engine and Gasoline Engine)

  • 김진영;박원옥;정성식;하종률
    • 한국자동차공학회논문집
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    • 제11권2호
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    • pp.16-21
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    • 2003
  • Natural gas is one of the promising alternative fuels because of the abundant deposits and the cleanness of emission gas. It can be used in conventional gasoline engine without major modification. Natural gas has some advantages than gasoline i.e. the high octane number, good mixing condition because of gas and wide inflamable limit. In the present study, a $1.8{\ell}$ conventional gasoline engine is modified for using the CNG as a fuel instead of gasoline. Performance and emission characteristics are compared between gasoline and CNG with 4 cylinder SI Engine which is controlled by programable ECU. Parameters of experimentation are equivalence ratio, spark timing and fuels. We analyzed the combustion characteristics of the engine using the cylinder pressure i.e. ignition delay, combustion duration and cycle variation. As a result, CNG engine shows lower exhaust emissions but brake torque is slightly reduced compared to gasoline engine. Overall combustion duration is longer than that of gasoline because of lower burning speed.

Experimental study on the performance of a turbocompound diesel engine with variable geometry turbocharger

  • Yin, Yong;Liu, Zhengbai;Zhuge, Weilin;Zhao, Rongchao;Zhao, Yanting;Chen, Zhen;Mi, Jiao
    • International Journal of Fluid Machinery and Systems
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    • 제9권4호
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    • pp.332-337
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    • 2016
  • Turbocompounding is a key technology to satisfy the future requirements of diesel engine's fuel economy and emission reduction. A turbocompound diesel engine was developed based on a conventional 11-Liter heavy-duty diesel engine. The turbocompound system includes a power turbine, which is installed downstream of a Variable Geometry Turbocharger (VGT) turbine. The impacts of the VGT rack position on the turbocompound engine performance were studied. An optimal VGT control strategy was determined. Experimental results show that the turbocompound engine using the optimal VGT control strategy achieves better performance than the original engine under all full load operation conditions. The averaged and maximum reductions of the brake specific fuel consumption (BSFC) are 3% and 8% respectively.

4실린더 4사이클 가솔린기관에서 배기계의 형상이 기관성능에 미치는 영향에 관한 연구 (A Study on the Effect of Exhaust Manifold Configuration on Engine Performance in a 4 Cylinder 4 Cycle Gasoline Engine)

  • 정수진;김태훈;조진호
    • 대한기계학회논문집
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    • 제18권3호
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    • pp.751-767
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    • 1994
  • Recent developments of S.I. engine, aiming to higher power, better fuel economy, lower air pollution and better driveability, have much focused on the importance of the role of computer simulation in engine research and development. In this point of view, improving engine performance requires finding some means to improve volumetric efficiency. Up to now there have been several attempts to optimize the intake and exhaust system of internal system of S.I. engine by computer simulation. There appear to be few studies available, however, of such simulation & experimental studies applied to the optimization of exhaust manifold configuration. In this study, gas exchange & power process of 4 cylinder S.I. Engine was studies numerically & experimentally, and governing equation of a one-dimensional unsteady compressible flow and combustion process were respectively solved by a characteristics method and 2-zone model. The aim of this study is to predict and investigate the influence of pressure wave interaction at the exhaust systems on engine performance with widely differing exhaust manifold configuration.

습도가 엔진성능에 미치는 영향에 대한 실험적 고찰 (Study on the Humidity Effect on Gas turbine Engine Performances)

  • 이보화;이경재;양수석;김춘택
    • 항공우주기술
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    • 제9권2호
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    • pp.98-104
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    • 2010
  • 대기 중의 수증기는 가스터빈엔진의 주요성능에 많은 영향을 끼친다. 습공기의 영향은 기온 및 기압이 높은 여름철 해면 고도, 높은 비행 마하수 그리고 낮은 엔진 회전수에서 이 더욱 두드러진다. 이러한 습공기 유입에 따른 가스터빈 엔진의 성능변화의 정도를 살펴보고자 가스터빈 시뮬레이션 프로그램(GSP)과 200lbf 급 초소형 터보제트 엔진의 고공환경 성능시험을 통해 습도가 엔진성능에 미치는 영향에 대하여 알아보았다. 고공환경 엔진시험을 통해, 건공기 유입에 비해 습공기 유입 시 순추력에서 2.826% 낮게, 비연료소모율에서 1.325% 높게 측정되었다.

복합모드형 ER엔진마운트의 성능평가 (I);엔진마운트의 제작 및 시험 (Performance Evaluation of a Mixed-Mode Type ER Engine Mount (I);Manufacturing and Test of Engine Mount)

  • 최영태;최승복
    • 대한기계학회논문집A
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    • 제24권2호
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    • pp.370-377
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    • 2000
  • This paper presents a mixed-mode type ER(electro-rheological) engine mount, and its vibration control performance for a passenger vehicle is presented. The field-dependent yield stress of a transfo rmer oil-based ER fluid is empirically distilled in both shear and flow modes. This is then incorporated with the governing equation of motion of the proposed mixed-mode(shear mode plus flow mode) type engine mount. The damping force is analyzed with respect to the intensity of the electric field and design parameters such as electrode gap. Subsequently, the ER engine mount which is equivalent to the conventional hydraulic engine mount in terms of the damping level is designed and manufactured. Both computer simulation and experimental test are undertaken in order to evaluate vibration isolation performance. In addition, this performance is compared with that of the conventional hydraulic engine mount.

EGR 적용 비도로 엔진의 쿨러 열화에 따른 질소산화물 배출특성 (NOx Emission Characteristic according to Aging of EGR Cooler in Non-Road Diesel Engine)

  • 이경복;오광철
    • 동력기계공학회지
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    • 제20권5호
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    • pp.37-45
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    • 2016
  • Exhaust gas recirculation has the advantage of being low-cost and easy to control of NOx emission. Therefore, it is most generally used to reduce NOx emission according to strengthen regulation. In the case of a non-road engine, such as the agricultural engine, since it mainly operate a middle or high-load state, NOx emission is decreased in accordance with the mapping range of the EGR rate, but results in an increase in the particulate matter which is caused to deposit and fouling problem of the EGR system. This problem has become an important issue for maintaining the performance of the engine, as well as emission performance. This study had examined the effects of cooler aging on the performance of heat transfer efficiency and NOx emission in non-road diesel engine. As a result of the EGR cooler aging during 200 hours engine operation, the cooling performance decreased about 25% compared with that of fresh cooler and the NOx emission increased about 14.6% on NRSC(non-road steady cycle) and 20% on NRTC(non-road transient cycle) compared with that of fresh cooler respectively.

습도 영향을 고려한 초소형 터보제트 엔진 성능시험 소개 (The introduction of Engine Performance Test for Miniature Turbojet Engine considering humidity effects)

  • 이보화;이경재;양수석;김유일
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제35회 추계학술대회논문집
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    • pp.335-338
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    • 2010
  • 대기 중의 수증기는 가스터빈엔진의 주요성능에 많은 영향을 끼친다. 습공기의 영향은 기온 및 기압이 높은 여름철 해면 고도, 높은 비행 마하수 그리고 낮은 엔진 회전수에서 그 영향이 더욱 두드러진다. 이러한 습공기 유입에 따른 가스터빈 엔진의 성능변화의 정도를 살펴보고자 200lbf 급 초소형 터보제트 엔진의 고공환경 성능시험을 통해 습도가 엔진성능에 미치는 영향에 대하여 알아보았다. 고공환경 엔진시험을 통해, 건공기 유입에 비해 습공기 유입 시 순추력에서 2.826% 낮게, 비연료소모율에서 1.325% 높게 측정되었다.

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인구통계적 특성에 따른 자동차 선택의 선호도에 관한 연구 (A Study on the Preference for Choosing an Automobiles according to the Demographic Characteristics)

  • 백성현;장경
    • 산업경영시스템학회지
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    • 제30권1호
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    • pp.25-32
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    • 2007
  • Automobile manufacturing companies should provide the products and service that can satisfy consumers who usually want various kinds of automobiles. This paper studied the relations among several demographic characteristics(gender, age, occupation, income) of consumers and automobile's attributes(engine performance, engine displacement, price, maintenance expenses, color, etc.) and preferred automobile(kind, size, company, price). For the relation research we established a model and related hypotheses and used a questionnaire survey, where 350 subjects were questioned. After the analysis, many statistically significant results are obtained : consumer's gender has relations with the preference for engine performance, engine displacement, price, color, and design; age has relations with the preference for engine displacement, maintenance expenses, free checking during A/S period, etc., occupation has relations with the preference for engine performance, engine displacement, price, maintenance expenses, fuel efficiency, etc. : income has relations with the preference for engine performance, engine displacement, price, maintenance expenses, mileage, reputation of car manufacturing companies, etc.; price and fuel efficiency has relations with the preference for car manufacturing companies. These results suggest the consumer-oriented sales of automobiles and are expected to be helpful for the effective strategy development of automobile marketing.

초소형 엔진의 윈드밀링 시동 성능 해석 (A study on Windmilling Start Performance of Micro Turbo-jet Engine)

  • 김완조;박휘섭;노태성
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2007년도 제29회 추계학술대회논문집
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    • pp.319-322
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    • 2007
  • 본 연구에서는 초소형 엔진의 윈드밀 시동시의 성능을 예측하기 위해 엔진의 주요 구성 부품의 성능의 손실해석을 통한 수치 방법을 개발하였다. 사류형 압축기를 가진 초소형 터보제트 엔진에 이 수치기법을 적용하여 탈설계점 및 설계점 영역에서 시동 특성을 해석하였다. 또한 각 설계 변수들의 윈드밀 시동 성능에 영향을 주는 민감도를 분석하였다.

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