• Title/Summary/Keyword: New concept engine

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Separate Type Rotary Engine Cycle Analysis (분리형 로터리엔진 사이클 해석)

  • Ki, Dockjong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.3
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    • pp.104-111
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    • 2019
  • A separate type rotary engine consisting of a compressor and an expander is under development. The engine motoring, compressor pressure, and fuel combustion have been tested with the initial prototype for operability checks of the mechanism. This paper describes an engine cycle analysis method designed specifically for this new-concept engine. The unique operational mechanism of the engine and the thermodynamic properties of each step of air intake, compression, filling of combustion chamber, combustion, expansion and exhaust were analyzed. The cycle efficiencies of this engine according to various engine design parameters as well as the cooling effect of compressed air between the compressor and expander can be easily calculated with this method; further, some case studies are presented in this paper.

The Research About Free Piston Linear Engine with Artificial Neural Network (인공 신경망을 이용한 프리피스톤 리니어 엔진의 연구)

  • AHMED, TUSHAR;HUNG, NGUYEN BA;LIM, OCKTAECK
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.3
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    • pp.294-299
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    • 2015
  • Free piston linear engine (FPLE) is a promising concept being explored in the mid-20th century. On the other hand, Arficial neural networks (ANNs) are non-linear computer algorithms and can model the behavior of complicated non-linear processes. Some researchers already studied this method to predict internal combustion engine characteristics. However, no investigation to predict the performance of a FPLE using ANN approach appears to have been published in the literature to date. In this study, the ability of an artificial neural network model, using a back propagation learning algorithm has been used to predict the in-cylinder pressure, frequency, maximum stroke length of a free piston linear engine. It is advised that, well-trained neural network models can provide fast and consistent results, making it an easy-to-use tool in preliminary studies for such thermal engineering problems.

A Numerical Study of Combustion Characteristics for HCCI Engine with Detailed Diesel Surrogate Chemical Mechanism (Diesel Surrogate 상세 반응 기구를 이용한 HCCI 엔진의 연소 특성에 관한 수치해석 연구)

  • Lee, Won-Jun;Lee, Seung-Ro;Lee, Chang-Eon
    • Journal of the Korean Society of Combustion
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    • v.16 no.2
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    • pp.9-15
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    • 2011
  • Homogeneous charge compression ignition(HCCI) is the best concept able to provide low NOx and PM in diesel engine emissions. This new alternative combustion process is mainly controlled by chemical kinetics in comparison with the conventional combustion in internal combustion engine. In this paper, combustion characteristics of HCCI engine with suggested diesel surrogate(heptane/toluene mixture fuel) reaction mechanism were numerically investigated by heptane/toluene mixture ratio and EGR ratio. As results, the ignition timing became faster with increasing of heptane, and an initial oxidation and the ignition timing of the mixture fuel were affected by heptane and toluene, respectively.

Effects of Ignition Energy Discharge Characteristics on the Lean Flammability Limit (점화에너지 방전특성이 희박연소한계에 미치는 영향)

  • 이중순;김진영;이종승;정성식;하종률
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.4
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    • pp.47-55
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    • 1998
  • A new ignition system concept was developed to improve ignition performance, accuracy of control and the reliability of the ignition system. The new ignition system has ho호 frequency discharge characteristics with 1.5-2.0 ms discharge duration, in place of the usual solitary longer duration event. We applied the system to a commercial engine to study its influence on the maximum combustion pressure attained during the cycle, when this peak pressure occurred, imep, variation rate of the engine speed and the flammability limit of a lean mixture. In this study, we clarified that the new ignition system had a beneficial effect of the lean mixture flammability limit. Also for a given mixture strength we found that the mew ignition system gave a higher peak cylinder pressure than in the case of the conventional ignition system.

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Detonation Wave Studies for CVC Engines of TBCC (TBCC를 위한 CVC 엔진의 데토네이션 현상 기초 연구)

  • Choi, J.Y.;Parent, Bernard;Cho, D.R.;Kang, K.;Shin, J.R.;Lee, S.H.;Yi, T.H.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.11a
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    • pp.326-329
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    • 2008
  • DARPA's hypersonic propulsion program VULCAN is aimed for development of Mach 4+ capable engine by combining current production turbofan engine such as F119 with CVC (Constant Volume Combustion) engine. Final goal is a TBCC(Turbo-based Combined Cycle) engine by combining with dual mode ramjet/scramjet engine. CVC is a common designation of new concept of high efficiency engines, such as Pulse Detonation Engine (PDE) or Continuous Detonation Engine (CDE), which use the detonation as a combustion mechanism. Present paper introduces the internationally collaborative research activities carried out in Aerospace Combustion and Propulsion Laboratory of the department of Aerospace Engineering of the Pusan national University.

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An Experimental Study on the Characteristics of Combustion and Emission in a Gasoline Direct Injection Type HCCI Engine by Controlling Mixture Formation (가솔린 직접분사식 HCCI 엔진의 혼합기 제어에 의한 연소 및 배기 특성에 관한 실험적 연구)

  • 김형민;류재덕;이기형
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.4
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    • pp.24-30
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    • 2004
  • As the environmental pollution becomes serious global problem, the regulation of emission exhausted from automobiles is strengthened. Therefore, it is very important to know how to reduce the NOx and PM simultaneously in diesel engines, which has lot of merits such as high thermal efficiency, low fuel consumption and durability. By this reason, the new concept called as Homogeneous Charge Compression Ignition(HCCI) engines are spotlighted because this concept reduced NOx and P.M. simultaneously. However, there is trade off between output and NOx in a HCCI engine. In this study, output and emission characteristics for a gasoline direct injection type HCCI engine were investigated to clarify the effects of intake air temperature, injection time and mixture formation. From these experiments, we found that the smoke was not produced when the fuel was injected earlier than BTDC 90$^{\circ}$. In addition, the output was increased because of delay of ignition time and NOx emission was decreased because of homogeneous charge of first injection in case of split injection.

A Post Web Document Clustering Algorithm (후처리 웹 문서 클러스터링 알고리즘)

  • Im, Yeong-Hui
    • The KIPS Transactions:PartB
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    • v.9B no.1
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    • pp.7-16
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    • 2002
  • The Post-clustering algorithms, which cluster the results of Web search engine, have several different requirements from conventional clustering algorithms. In this paper, we propose the new post-clustering algorithm satisfying those requirements as many as possible. The proposed Concept ART is the form of combining the concept vector that have several advantages in document clustering with Fuzzy ART known as real-time clustering algorithms. Moreover we show that it is applicable to general-purpose clustering as well as post-clustering

Fuzzy Clustering Algorithm for Web-mining (웹마이닝을 위한 퍼지 클러스터링 알고리즘)

  • Lim, Young-Hee;Song, Ji-Young;Park, Dai-Hee
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.3
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    • pp.219-227
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    • 2002
  • The post-clustering algorithms, which cluster the result of Web search engine, have some different requirements from conventional clustering algorithms. In this paper, we propose the new post-clustering algorithm satisfying those of requirements as many as possible. The proposed fuzzy Concept ART is the form of combining the concept vector having several advantages in document clustering with fuzzy ART known as real time clustering algorithms on the basis of fuzzy set theory. Moreover we show that it can be applicable to general-purpose clustering as well as post clustering.

Product Family Design using Formal Concept Analysis and Ontology (정형적 개념 분석과 온톨로지를 활용한 제품계열 정보 설계)

  • Lee, Hee-Jung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.3
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    • pp.110-117
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    • 2012
  • A product family design has received much attention over the last several decades, since a product family-based development shortens lead-times and reduces cost, as well as increases efficiency and effectiveness of the product realization process. It is challenging work, however, to define the product family design in the heterogeneous product development environments, due to myriads of products related information described in different ways across products in any companies. In this paper, we provided a way of defining product family design framework using formal concept analysis and ontology language. Based on this, the specific product family can be derived by ontological reasoning, and the new product concept can be also expanded in the framework. The proposed framework is formalized using OWL (Web Ontology Language) and implemented in $Prot{\acute{e}}g{\acute{e}}$. Actual product family design algorithm is carried out using FaCT++ engine, a plug-in to $Prot{\acute{e}}g{\acute{e}}$, and the benefits of the proposed method are also demonstrated through a case study.

Three-dimensional Analysis of Flow Characteristics for Intake Valve Design (흡기밸브 형상에 따른 3차원 유동특성 해석)

  • 김득상;이상진;조용석;엄인용
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.4
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    • pp.1-6
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    • 2003
  • Steady flow bench test is a practical, powerful and widely used in most engine manufacturers to give a design concept of a new engine. In order to use steady data as a performance index, it is necessary to build some database, which can correlate the port characteristics with engine data. However, it is very difficult to investigate all port shapes with experimental tools. The steady flow scheme is relatively simple and its results are bulk ones such as flow rate and momentum of flow. Therefore a CFD code can be easily applied to the port evaluation. In this study, the steady flow test was simulated through three-dimensional analysis on intake port design for comparing with experimental data and confirming the feasibility of applying analytic method . for this purpose, the effect of valve curvature on flow rate was estimated by a CFD code. Numerical results were compared with those of real steady flow tests. As a result, the results of 3-D analysis were almost consistent with experimental data.