• Title/Summary/Keyword: Automotive Structure

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Damping performance Analysis for an Electronically Contralled Shock Absorber (연속 가변형 충격흡수기의 감쇠성능 해석)

  • 박재우;이동락;백운경
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.2
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    • pp.192-201
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    • 2001
  • Analyzing internal structure, flow rate and dynamic behavior characteristics of electronically controlled shock absorber, damping performance limit is identified to comprise the two reciprocal characteristics of ride comfort and handling safety. Regardless of its lower performance than the active suspension control system, the semi-active suspension control system has been taking interest because of its absolutely higher performance than passive suspension system. Since the pervious studies have been concentrated mostly on analytic aspect and survey on the internal structure of the shock absorber remain insufficient, the main discourse of this paper is focused on analyzing the nonlinear shock absorber which varies the damping force of semi-active suspension system and the dynamic characteristics of the solenoid valve, a sort of pressure valve, and proposing the design factors of importance.

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Numerical Analysis for the Detailed Structure and the Soot Formation Mechanism in Counterflow Ethylene-Air Nonpremixed Flame (대향류 에틸렌/공기 비예혼합 화염의 구조 및 Soot 생성 메커니즘 해석)

  • 임효준;김후중;김용모
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.5
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    • pp.40-54
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    • 1999
  • The flame structure and soot formation in the counterflow Ethylene-Air nonpremixed flame are numerically analyzed. The present soot reaction mechanism involves nucleation, surface growth, particle coagulation, and oxidation steps. The gas phase chemistry and the soot nucleation, surface growth reactions are coupled by assuming that the nucleation and soot mass growth has the certain relationship with the concentration of benzene and acetylene. In terms of the centerline velocity and the soot volume fraction, the predicted results are compared with the experimental data. The detailed discussion has been made for the sensitivity of model constants and the deficiencies of the present model. Numerical results indicated that the acetylene addition to the soot surface plays the dominant role in the soot mass growth for the counterflow nonpremixed flame.

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Effect of Damkohler Number on Superequilibrium Concentration and Flame Structure in Turbulent Nonpremixed Jet Flames (Damkohler 수가 비예혼합 CO/$H_2$/$N_2$ 난류 화염장에서의 초과평형농도 및 화염구조에 미치는 영향)

  • 김군홍;김용모;윤명원
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.6
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    • pp.51-58
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    • 2002
  • The RPV(Reaction Progress Variable) combustion model has been applied to numerically investigate the effects of Damkohler number on the superequilibrium concentration and flame structure in the nonpremixed turbulent flames. Computations are performed for the two turbulent jet flames of CO/H$_2$/N$_2$(40/30/30 volume percent) having the same jet Reynolds number of 16,700 but different nozzle diameters(4.58mm and 7.72mm). The detailed discussions have been made for the interaction between fluid dynamics and chemistry in the flame field.

A Study on the Performance Improvement in the Intake System of a Large-sized Commercial Bus (대형버스 흡기시스템 성능 개선에 관한 연구)

  • Lyu, Myung-Seok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.2
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    • pp.16-21
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    • 2005
  • The performance of reciprocating internal combustion engine is a strong function of the air intake system configuration. In order to improve engine power, it is essential to optimize the air induction system. In this study, a numerical investigation has been carried out for the three-dimensional flow and pressure characteristics in air intake system of a large-sized commercial bus. CFD simulations using STAR-CD were also perform ed to evaluate effects of intake duct geometry and structure variation inside air cleaner on the negative pressure distribution of overall intake system. Studies for improving the back pressure distribution have been proposed and quantitatively examined based on intensive case studies.

A Study on an Engine Control System using an Object Oriented Programming Method (객체지향 프로그래밍 기법을 이용한 엔진제어시스템에 관한 연구)

  • 윤팔주;이상준;선우명호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.3
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    • pp.98-109
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    • 2000
  • A new PC-based Engine Control system (ECS) is developed using an object oriented programming method. This system provides more convenient environment for engine tests, easier user interface and extended functions. A Windows-based ECS software is developed with class, and the class structure is built on encapsulation and abstraction. The closed-loop engine control scheme can be easily constructed by using dynamic link library and multitasking. This means that a user can perform desired experiments without clear knowledge of the hardware structure of the ECS. Also this system allows a user to individually control the ignition and fuel injection for each cylinder in a simple manner such as through a keyboard/mouse or in a real-time operation from a closed-loop control program.

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A Study on the Structural Design of a Seat frame in Automotive Vehicles (승용차 시트프레임의 구조설계에 관한 연구)

  • 김홍건;조영태;최금호;이병휘
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.05a
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    • pp.159-163
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    • 1999
  • A seat frame structure in automotive vehicles made of polymer matrix composite to achieve weight reduction at low cost was developed. In order to design and manufacture the actual product, studies on material selection, and structural analyses were performed. Structural analyses were performed with a finite element analysis. Analyses were done for several cases suggested in various safety regulations of FMVSS(Federal Motor Vehicle Safety Standards). Each result was utilized to modify the actual shape to obtain a lighter, safer and more stable design. The final design was used to produce a sample bottom plate of the seat structure. Substitution of the material resulted in a weight reduction effect with equivalent strength, fatigue and impact characteristics. Furthermore, several effects from the replacement of the material besides weight reduction were also examined.

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Micromachined ultra-wideband beamforming network for automotive radar front ends (마이크로머신 기술로 제작한 자동차 프런트엔드용 초광대역 빔성형 네트워크)

  • Corona-Chavez, Alonso;Liamas-Garro, Ignacio;Kim, Jung-Mu;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2386-2388
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    • 2005
  • As anti-crash and pre-crash systems in vehicles become more extensively used, the need for high performance short-range radars is playing an increasing role. This paper presents the design of a micromachined, ultra-wideband beamformer centered at 24 GHz for automotive short-range radar systems. This beamformer is a Butler matrix designed using ultra-wideband transmission-line couplers, which consist of a multilayered structure that exhibits wider bandwidth compared to conventional microstrip branch-line couplers. The circuit has been designed on a quartz substrate, and to achieve the desired coupling, lines suspended on BCB layers located at specific parts of the circuit were used, achieving a three metal layered structure in form of wide microstrips, that give low loss and a wideband response. In this paper the design and fabrication procedure of the proposed beamformer are fully described.

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Analysis of Spray and Flow Fields for Development of Spark-ignited Direct Injection Engine (가솔린 직분식 엔진의 연소실 개발을 위한 분무 및 유동장 해석)

  • Choi, K.H.;Park, J.H.;Lee, N.H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.202-209
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    • 1998
  • For development of SDI(Spark-ignited Direct Injection) engine, stratified mixture formation with adequate strength at spark plug was required in wide range of engine operating conditions. So, spray structure under high ambient pressure and spray distribution after impingement on piston bowl in motoring engine was visualized by using laser equipments. Also, incylinder bulk flow structure was measured by using PIV (Paiticle Image Velocimetry) system. Counter-rotating tumble port and bowl piston was found effective to conserve bulk motion directed to spark plug in compression stroke. In addition, mask attached near valve seat in intake port was proposed to attenuate conventional tumble component and enhance counter-rotating tumble component.

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Development of a Graphic User Interface Program for Suspension Design (현가장치 설계용 그래픽 사용자 접속 프로그램 개발)

  • Kim, H.K.;Yoo, H.H.;Choi, K.R.;Lee, M.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.7-14
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    • 1998
  • A graphic user interface program for the design of vehicle suspension system is developed in this work. Graphic templates are designed by using a graphic language and a library and given to users for interactive data input. Several suspension types are graphically given, and the information of hard points can be directly provided on the graphic templates by users. The information is saved in a data structure which can be efficiently accessed, and transformed into another data format. The data transformation is for the interface to an analyzer by which suspension design characteristics can be calculated.

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An Energy Absorption Characteristic of Thin-Walled Structure Members by Crushing Load (충돌에 의한 차체 박육구조부재의 에너지 흡수특성에 관한 연구)

  • Yang, I.Y.;Sim, J.K.;Kim, S.K.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.5
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    • pp.74-81
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    • 1995
  • In this paper, the crushing tests of circular tubes under axial impact loading are conducted to investigate the energy absorption abilities. A cross head with 18kg launched by the compressed air collides against circular tubes. Circular tubes used for this experiment are Al and CFRP laminates, which have 8 ply with $15^{\circ}$ and $45^{\circ}$. The absorbed energy unit mass and volume of the CFRP specimen with $15^{\circ}$ are higher than those of aluminum specimen. CFRP specimen having small stacking angle have better energy absorption abilities than that of large stacking angle.

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