• 제목/요약/키워드: Fuel economy evaluation

검색결과 53건 처리시간 0.021초

가솔린 차량의 차대동력계 표준모드 별 추종성 분석 및 배출가스 특성에 관한 연구 (A Study on the the Follow-up Analysis and the Characteristics of Exhaust Gas by Standard Mode of Chassis Dynamometer of Gasoline)

  • 서동춘;박성영
    • 한국산학기술학회논문지
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    • 제20권9호
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    • pp.29-34
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    • 2019
  • 본 연구에서는 배출가스 및 연비시험에서 드라이브 품질을 평가하기 위해서 가솔린 시험차량 1대를 선정하여 측정하고, 그 측정결과와 제작사가 제시한 값과 비교하여 허용오차 범위(연비-5%, 온실가스+5%, 이하 "허용오차범위")를 초과하는지 평가하였다. 측정결과의 평균값이 제시한 값과 유효한지 데이터를 분석하였다. 본 연구에서는 SAE J2951 평가방법을 기반으로 시험자간의 주행모드 추종성을 가지고 허용오차범위에 대한 데이터 확보를 위해 시험을 수행하였다. 시험차량은 2L급 가솔린차량을 선정하였다. 검증결과 주행 추종성은 고의적인 주행조건에서 전체 값이 커지고, 부드러운 주행조건 일 때, 값이 줄어드는 것을 확인하였다. 주행 추종성 분석결과 수치가 1에 가까울수록 정확하게 주행한 것이며, (-) 음의방향으로 분포하고 있는 가혹조건과 (+) 양의방향으로 분포하고 있는 완만한 조건이라 할 수 있다. 본 연구에서 수행된 시험의 분석을 시험자간 드라이브 추종성에 대한 기초 데이터를 확보하였고, 이러한 기초 데이터는 연비모드의 목표 속도 허용범위 내에서의 운전추종성에 대한 연비 상관성을 분석하였고, 향후 측정결과는 연비측정 모드별 배출가스 DB 확보 및 연비제도에 중요한 기초 자료로 활용될 것으로 사료된다.

Mg-Sn-Al-Zn 합금을 적용한 컨트롤암의 정강도 평가에 관한 연구 (Evaluation of the Static Strength of a Mg-Sn-Al-Zn Alloy Used for an Automotive Control Arm)

  • 이상익;김병민;임성곤;이정환
    • 소성∙가공
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    • 제25권3호
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    • pp.155-160
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    • 2016
  • Magnesium(Mg) alloys have been evaluated as replacements for steel or aluminum parts in the automobile industry because of the fuel economy they can provide through reducing weight. The application of Mg alloys has been limited due to its low formability at room temperature, which results from a small number of active slip systems. In the current study, an extruded TAZ711(Mg-7Sn-1Al-1Zn) alloy was warm forged into an automotive control arm to evaluate its formability at various forging temperature. Warm forging was conducted at temperatures of 200, 250, 350 and 450℃. Static strength evaluation was performed on the as-forged specimen at 250℃. The results showed good static strength.

소형 트럭용 CNG/가솔린 겸용 엔진 개발과 성능 분석 (Development of CNG/Gasoline Bi-fuel engine for a small truck and the evaluation of engine performance)

  • 권오운;김재수;박용국;김성준
    • 산업기술연구
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    • 제26권B호
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    • pp.21-28
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    • 2006
  • A diesel truck of 1 ton is re-powered by a gasoline engine and the fuelling system of gasoline engine modified to gasoline/CNG bi fuel system. The engine characteristics such as fuel economy and power are evaluated by driving rest, sloping test and dynamometer. The driving test prove the driving cost is saved by 55% and the maximum speed is raised by 13%, which is mainly due to the higher calorific value of CNG. The sloping test is done on the road of which slope is 15%. The truck shows the mean velocity of 88km/h, which means that a re-powered truck is working fine. The BHP are measured by dynamometer. The power and torque produced by a re-powered truck are reduced by 13% and 14% respectively from the power of gasoline engine. The BHP reduction is one of main problems which one has to solve in near future.

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연비 향상을 위한 반력 생성형 에코페달의 설계와 성능검증 (Design and Performance Validation of Tactile Force Generating Type Eco-pedal to Improve Fuel Economy)

  • 김지수;탁태오
    • 대한기계학회논문집A
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    • 제40권11호
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    • pp.963-970
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    • 2016
  • 본 연구는 가속페달에 반력을 생성하여 운전자의 경제운전을 유도하기 위한 에코페달의 설계와 성능 검증을 다룬다. 에코페달의 제어로직은 사전에 설정된 "허용가속도"를 바탕으로 현재 속도에서 허용되는 연료소비량을 정하고 이를 실제 연료소비량과 비교하여 에코페달의 작동을 결정하는 방식을 제안하였다. 폐달 반력은 운전자가 충분히 인지하되 불쾌감을 느끼지 않아야 하며, 차량의 정상 거동에 간섭이 없어야 한다. 스텝형과 램프형 반력 등과 같이 페달 답력이 급속하게 증가하는 형태의 반력은 반력 작동이 멈춘 직 후 운전자의 답력에 의한 급작스러운 가속 현상 때문에 적용이 어렵고, 이러한 문제가 없는 진동형 반력을 채택하였다. 진동형 반력의 주파수, 진폭, 작동시간은 운전자의 주관적 평가와 연비 향상 효과를 고려하여 결정하였다. 본 연구에서 제안된 에코페달을 차량에 장착하여 주행시험을 실시한 결과 고속도로와 시내주행에서 각각 13%와 15%의 연비향상 효과를 보여주었다.

천연가스 개조 승용차에 대한 실험적 연구(2) - 분사 시스템 평가 (Experimental Study on Natural Gas Conversion Vehicle(2) - Evaluation of Injection System)

  • 김형구;권순태;엄인용
    • 한국자동차공학회논문집
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    • 제23권4호
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    • pp.444-453
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    • 2015
  • In the previous study, several problems were observed in a NG conversion vehicle, which were fail of air-fuel ratio closed loop control, aggravated fuel economy, increased harmful emission and declined roadability. It was provisionally supposed that the mismatch of injection system with the engine caused these performance deterioration. In this context, the characteristics of fuel injection system of commercial conversion kit for NG were investigated experimentally varying the engine speed, fuel rail pressure and volume. The results are as follows; The injection quantity decreases as the engine speed increases due to the extremely small rail volume of the presenting system and flow rate of No. 2 injector are always lower than that of the other ones regardless of the speed under the dynamic operation condition. Furthermore the existing system does not meet the required fuel quantity for the normal engine operation over 3000 RPM. On the other hands, the large rail volume systems ease and/or eliminate the difference of injection quantity between the injectors according to the speed variation, however, these systems decrease injection flow rate and still cannot supply sufficient fuel. Finally, suitable combination of the higher rail pressure and the larger rail volume might be a solution about these problems.

특성 손실 평가를 통한 하이브리드 자동차 동력전달장치의 빠른 설계 최적화 (Computationally Effective Optimization of Hybrid Vehicle Powertrain Design Using Characteristic Loss Evaluation)

  • 박세호;안창선
    • 한국자동차공학회논문집
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    • 제23권6호
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    • pp.591-600
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    • 2015
  • The efficiency of a powertrain system of hybrid vehicle is highly dependent on the design and control of the hybrid powertrain system. In other words, the optimal design of the powertrain systems is coupled with optimal control of the powertrain system. Therefore, the solution of an optimal design problem for hybrid vehicles is computationally and timely very expensive. For example, dynamic programming, which is a recursive optimization method, is usually used to evaluate the best fuel economy of certain hybrid vehicle design, and, thus, the evaluation takes tens of minutes to several hours. This research aims to accelerate the speed of efficiency evaluation of hybrid vehicles. We suggest a mathematical treat and a methodological treat to reduce the computational load. The mathematical treat is that the dynamics of system is discretized with sparse sampling time without loss of energy balance. The methodological treat is that the efficiency of the hybrid vehicle is inferred by characteristic loss evaluation that is computationally inexpensive. With the suggested methodology, evaluating a design candidate of hybrid powertrain system is taken few minutes, which was taken several hours when dynamic programming is used.

선적화물량에 따른 살적화물선의 최적적화중량준 및 속력의 결정에 관한 연구 (A Study on Dry Bulkers' Optimal Deadweight and Speed under Certain Available Cargo Lot Sizes)

  • 이명진
    • 한국항해학회지
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    • 제8권1호
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    • pp.17-48
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    • 1984
  • The economy of ship's size and speed is affected by the freight rates, sailing distances, cargo handling rates, fuel oil prices and even interest rates of the borrowed funds. It can be a step more powerful measures if the economic evaluation model takes in a cargo lot size which prevails in the shipping markets. This paper has dealt with hypothetical cargo lots which happen to the market with uniform distribution in probability. The evaluation models are either profit maximization method or cost minimization method. The former compares among different voyages in profitability to the invested funds, the later defines the transportation efficiency in ton-mile unit and be used in comparing two or more transportation means. This paper adopted both of above methods to derive out ships economical evaluation contours for the various ship's speed and deadweight for certain cargo lot sizes, which can be used as important managerial decision data in purchasing ships or selecting a most profitable one among the proposed voyages. This evaluation contours will also be efficiently used in appraising so called "handy size ships" in connection with port water depth and conditions of voyage tracks.ge tracks.

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EMERGY 평가에 의한 부산광역시의 지속적인 발전가능성 평가 (A Study on the Sustainable Development of Pusan Metropolitan City by the EMERGY Evaluation)

  • 손지호;이석모
    • 한국환경과학회지
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    • 제9권3호
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    • pp.185-191
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    • 2000
  • Sustainable development has been the key concept, both in economic policies and in environmental management since 1970s. In the view of systems ecology, sustainable resource use strategies are considered to be essential in achieving sustainable development. During the last three decades, the discipline of systems ecology has applied ecological energetic analysis to the evaluation of the contribution of natural environments to economic systems. ENERGY analysis of main energy flows driving the economy of humans and life support systems of a city was made including environmental energies, fuel, and inputs, all expressed as solar emjoules. Total EMERGY use of Pusan was 3.89 E22 sej/yr, about 90 percent of it was purchased sources from outside during eleven years from 1985 to 1995. EMERGY flows from the environment were less than 10 percent. EMERGY yield ratio and environmental loading ratio were 1.10 and 10.45, respectively. EMERGY sustainability index is there(ore less than one, which is indicative of highly developed consumer oriented economies. Development of a city has been achieved in the short run by the economic growth, but it can be sustained in the long run by the use of renewable resource systems.

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변형률-수명 평가기법을 이용한 Al/CFRP 하이브리드 적층 복합재의 피로수명 측정 (The Estimation of Fatigue Life for Al/CFRP Hybrid Laminated Composites using the Strain-Life Method)

  • 양성진;권오헌;전상구
    • 한국안전학회지
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    • 제36권3호
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    • pp.7-14
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    • 2021
  • Hybrid laminated Al/carbon-fiber-reinforced plastic (CFRP) composites are attracting considerable attention from industries such as aerospace and automobiles owing to their excellent specific strength and specific rigidity. However, when this material is used to fabricate high-pressure fuel storage containers subjected to repeated fatigue loads, fatigue life evaluation for the working load is regulated as an important criterion for operational safety and ease of maintenance. Among the existing evaluation methods for these vessels, the burst test and the hydraulic repeat test require expensive facilities. Thus, the present study aims to develop an improved fatigue life test for Al/CFRP laminated hybrid composites. The test specimen was manufactured using a curved mold considering the shape of a type III high-pressure storage container. The strain-life method was used for fatigue life evaluation, and the life was predicted based on the transition life. The results indicate that the more complex the CFRP stacking sequence, the longer is the transition life. This test method is expected to be useful for ensuring the fatigue safety and economy of hybrid laminate composites.

축냉 시스템이 차 실내 열 쾌적성에 미치는 영향에 관한 실험적 연구 (Experimental Study of the Effect on Cabin Thermal Comfort for Cold Storage Systems in Vehicles)

  • 이대웅
    • 한국자동차공학회논문집
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    • 제23권4호
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    • pp.428-435
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    • 2015
  • This paper presents the experimental study of cabin thermal comfort using a cold storage heat exchanger in a vehicle air-conditioning system. Recent vehicle-applied ISG functions for fuel economy and emission, but when vehicles stop, compressors in the air-conditioning system stop, and the cabin temperature sharply increases, making passengers feel thermal discomfort. This study conducts thermal comfort evaluation in the vehicle, which is applied to a cold storage system for the climate control wind tunnel test and the vehicle fleet road test with various airflow volume rates and ambient temperatures blowing to the cold storage heat exchanger. The experimental results, in the cold storage system, air discharge temperature is $3.1-4.2^{\circ}C$ lower than current air-conditioning system when the compressor stops and provides cold air for at least 38 extra seconds. In addition, the blowing airflow volume to the cold storage heat exchanger with various ambient temperature was examined for the control logic of the cold storage system, and in the results, the airflow volume rate is dominant over the outside temperature. For this study, a cold storage system is economically useful to keep the cabin at a thermally comfortable level during the short period when the engine stops in ISG vehicles.