• Title/Summary/Keyword: Valve Dynamics

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Co-simulation for Dynamic Characteristic Analaysis of Solenoid Valve for Vehicle (자동차용 솔레노이드 밸브의 동특성을 위한 연성해석)

  • Kim, Ki-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.3821-3826
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    • 2014
  • This paper proposes a methodology for developing the performance of a solenoid valve for vehicles based on the dynamic analysis model by an electromagnetic field. The high performance solenoid model with a low current and high thrust was induced through the shape optimal design of the yoke and plunger. To perform the dynamic analysis of the solenoid valve, the input current profile was analyzed. The speed and thrust information was analyzed by FEM with this current profile. The co-simulation method of the circuit model of control logic and electromagnetic model of the solenoid valve was also proposed to analyze the performance with several current patterns. Finally, the performance of the original model and optimal one was compared.

Three-Dimensional Analysis on Induction Port and In-cylinder Flow for Various Valve Lifts in an SI Engine (SI 엔진의 밸브 리프트에 따른 흡입 포트 및 실린더내 정상 3차원 유동장 해석)

  • Kim, Y.N.;Lee, K.H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.5
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    • pp.82-89
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    • 1995
  • The three-dimensional fluid motion through the intake port and cylinder of a single DOHC SI engine was investigated with a commercial computational fluid dynamics simulation program, STAR-CD. This domain includes the intake port, intake valves and combustion chamber. Steady induction port flows for various valve lifts have been simulated for an actual engine configuration. The geometry was obtained by direct interface with a three-dimensional CAD software for complicated port and valve shape. The computational grid was generated using the commercial preprocessor ICEM CFD/CAE. Detailed procedures were presented on the generation of the geometry and the block-structured mesh. A standard k-${\varepsilon}$ turbulent model was applied to consider the complexity of the geometry and the fluid motion. The global flow patterns and the distributions of various quantities, such as pressure, velocity magnitude around the valve seat etc., were examined. The computational results, such as mass flow rate, discharge coefficient etc., for various valve lifts were compard with the experimental results and the computational results were found in good agreement with the experiment.

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Frequency Dependent Damping for a Nonlinear Vehicle Active Suspension System (비선형 차량능동현가시스템의 주파수 감응감쇠 특성연구)

  • Kim, J.Y.
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.2
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    • pp.45-54
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    • 2011
  • A vehicle suspension system performs two functions, the ride quality and the stability, which conflict with each other. Among the various suspension systems, an active suspension system has an external energy source, from which energy is always supplied to the system for continuous control of vehicle motion. In the process of the linearization for the nonlinear active suspension system, the frequency dependent damping method is used for the exact modelling to the real model. The pressure control valve which is controlled by proportional solenoid is the most important component in the active suspension system. The pressure control valve has the dynamic characteristics with 1st order delay. Therefore, It's necessary to adopt the lead compensator to compensate the dynamics of the pressure control valve. The sampling time is also important factor for the control performances. The sampling time value is proposed to satisfy the system performances. After the modelling and simulation for the pressure control valve and vehicle dynamic, the performances of the vehicle ride quality and the stability are enhanced.

Evaluation of Numerical Model of a Ball Valve used for a Gas Pipeline (가스 파이프라인용 볼 밸브의 수치해석 모델 평가)

  • KIM, CHUL-KYU;LEE, KYOUNG-KEUN;LIM, TAE-GYUN;JANG, CHOON-MAN
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.6
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    • pp.764-772
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    • 2016
  • This paper presents on the evaluation of numerical analysis model of a ball valve used for a gas pipeline. The ball valve has important role to control the gas flow of the pipeline as well as safety operation to prevent gas explosion at the emergency. For the validation of numerical simulation, the computational domains are introduced three different types: a hexahedron chamber connected to a pipeline outlet without considering the geometry of pressure tubes, a pipeline only considered the geometry of pressure tubes, and a pipeline connected both of the a hexahedron chamber and pressure tubes. The commercial code, SC/Tetra, is introduced to solve the three-dimensional steady-state Reynolds-averaged Navier-Stokes analysis in the present study. The valve flow coefficient and valve loss coefficient with respect to the valve opening rate of 30%, 50%, and 70% are compared with experimental results. Throughout the numerical analysis for the three analysis domains, pressure computed along the pipeline is affected by computational domains. It is noted pressure obtained by the computational model considering both of the a hexahedron chamber and pressure tubes has a relatively good agreement to the experimental data.

Numerical Analysis for Evaluation of Ejection Capacity Relationship of Safety Valves in Pressure Regulating Station (II) - Flow Analysis and Required Effective Discharge Area of Safety Valve - (정압기지내의 안전밸브 분출용량 관계식 검증을 위한 유동해석 (II) - 안전밸브 유동 해석 및 필요분출면적 -)

  • Gwon, Hyuk-Rok;Roh, Kyung-Chul;Kim, Young-Seop;Lee, Seong-Hyuk
    • Journal of the Korean Institute of Gas
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    • v.12 no.2
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    • pp.105-109
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    • 2008
  • A safety valve has a valve mechanism for the automatic release of gas from piping system when the pressure exceeds preset limit cause of a defect of a pressure regulator, condensation of water in a pipe. Therefore, for the safety of pressure regulating station, it is essential to study the flow regime and characteristics of safety valve. This article presents the numerical analysis on the flow analysis, the ejection capacity and required effective discharge area of the safety valve that is established in pressure regulating station. Then, the results are compared and analyzed with domestic and foreign regulations such as API(America Petroleum Institute), EN(European Standard), and NF(Norme Francise). Moreover, the installation number of safety valve is considered by using domestic and foreign regulations and maximum reguired effective discharge area of safety valve.

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Nonlinear analysis of a pneumatic actuation system by digital simulation (전산모사에 의한 공압구동장치의 비선형 해석)

  • 조택동;신효필;문의준
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.1104-1109
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    • 1991
  • Recently, Pneumatic Actuation System (PAS) has been used increasingly as a high performance fin-control servo actuation systems because of the special advantages of pneumatic units: primarily their low cost, small size, light weight, and tolerance to broad temperature extremes. In this study, a nonlinear model of PAS is derived through the detailed analysis of the major components in the typical system. The model includes nonlinear flow-pressure relationships of the flow through the solenoid valve openings and orifices, PWM algorithm for driving two solenoid valves as a closed-center 3-way valve for minimum gas consumption, solenoid valve dynamics, saturation, and friction. Simulation results are compared with the experimental ones for square and sinusoidal inputs to see the validity of the model. Independent of the shape and magnitude of the input signals, both results are in good agreements with minor difference.

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FLUID STRUCTURE INTERACTION ANALYSIS OF AUTOMOTIVE REFRIGERANT COMPRESSOR (자동차 냉매 압축기의 FSI(Fluid-Structure Interaction) 해석)

  • Son, I.G.;Pae, S.M.;Kim, K.I.;Yoon, Y.S.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.93-98
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    • 2010
  • One of the most effective key factors to improve performance of automotive reciprocating compressor is the design of suction and discharge reed valves. Reed valves are also the major sources of compressor noise. Valve motion is highly coupled with refrigerant flow. In this study, a process of fluid-structure interaction analysis was developed to predict the cylinder inner flow and the dynamic behavior of valve simultaneously. Interface programs computational structural dynamics code. The full cycle simulations of compressor were performed using FSI analysis was alidated by comparing the simulation results with the experimental results.

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Shape Optimization to Minimize The Response Time of Direct-acting Solenoid Valve

  • Shin, Yujeong;Lee, Seunghwan;Choi, Changhwan;Kim, Jinho
    • Journal of Magnetics
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    • v.20 no.2
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    • pp.193-200
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    • 2015
  • Direct-acting solenoid valves are used in the automotive industry due to their simple structure and quick response in controlling the flow of fluid. We performed an optimization study of response time in order to improve the dynamic performance of a direct-acting solenoid valve. For the optimal design process, we used the commercial optimization software PIAnO, which provides various tools for efficient optimization including design of experiments (DOE), approximation techniques, and a design optimization algorithm. 35 sampling points of computational experiments are performed to find the optimum values of the design variables. In all cases, ANSYS Maxwell electromagnetic analysis software was used to model the electromagnetic dynamics. An approximate model generated from the electromagnetic analysis was estimated and used for the optimization. The best optimization model was selected using the verified approximation model called the Kriging model, and an optimization algorithm called the progressive quadratic response surface method (PQRSM).

System design of an air-cooled 3-stage reciprocating air compressor and performance testing (공랭식 3단 왕복동 공기압축기의 시스템 설계 및 성능시험)

  • Lee, An-Seong;Kim, Yeong-Cheol;Jeong, Yeong-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.10
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    • pp.1380-1391
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    • 1997
  • A 150 m$^{3}$/hr, 30 kg/cm$^{2}$, air-cooled 3-stage reciprocating air compressor is designed to be used in starting large diesel engines. A basic design procedure is presented to meet the targeted pressure and flow rate, and especially the volumetric efficiency. Temperature and stress analyses of the cylinder are performed using FEM modelings. The dynamics of valve system is analyzed and stress at the valve seat due to valve impact is evaluated. To reduce friction loss and wear at the compressor engine system, tribological design practices are suggested. Fin-type coolers are designed to dissipate generated compression heat at each stage. Finally, a prototype is manufactured and performance test is carried out utilizing an air tank. Performance results are compared to the design targets, other foreign specifications, and some quality standards.

A Study on the flow of Ball Check valve in the Oil Jet for cooling the Piston (피스톤 냉각용 Oil Jet내 볼 체크 밸브 주위 유동 연구)

  • Kwon, J.H.;Jung, H.Y.;Lee, J.H.;Choi, Y.H.;Lee, Y.W.
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.195-199
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    • 2005
  • As vehicles are recently becoming more important in our life, the study for engine capacity has been conducted for many years. Specially, the study on lubrication in the engine is needed to develop engine capacity. The role of lubrication is to reduce fraction, manage the temperature and protect from corrosion etc. At the view point of the engine, lubrication and cooling of the engine have an effect on the life and efficiency, so we have to study this problem. Ball check valve is located in the inlet of the Oil Jet. Ball check valve is used to control the flow rate of the engine oil, which cools and lubricates the engine. Flow rate at the oil jet is very important, so the study for this problem is needed to conduct researches. The point of this study is to compute the flow rate and the flow in oil jet. The results of this study is that the mass flow rate is satisfied with the research which is obtained at the experiment.

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