• Title/Summary/Keyword: Primary Suspension

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An Analytical Study on the Gas-Solid Two Phase Flows

  • Sun, Jianguo;Kim, Heuy-Dong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.356-363
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    • 2012
  • This paper addresses an analytical study on the gas-solid two phase flows in a nozzle. The primary purpose is to get recognition into the gas-solid suspension flows and to investigate the particle motion and its influence on the gas flow field. The present study is the primal step to comprehend the gas-solid suspension flow in the convergent-divergent nozzle. This paper try to made a development of an analytical model to study the back pressure ratio, particles loading and the particle diameter effect on gas-solid suspension flow. Mathematical model of gas-solid two phase flow was developed based on the single phase flow models to solve the quasi-one-dimensional mass, momentum equations to calculate the steady pressure field. The influence of particles loading and particle diameter is analyzed. The results obtained show that the suspension flow of smaller diameter particles has almost same trend as that of single phase flow using ideal gas as working fluid. And the presence of particles will weaken the strength of the shock wave; the bigger particle will have larger slip velocity with gas flow. The thrust coefficient is found to be higher for larger particles/gas loading or back pressure ratio, but it also depends on the ambient pressure.

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Optimization of the Suspension Characteristics for a High Speed Electrical Multiple Train on the Stage of Basic Design (기본설계 단계에서 분산형 고속철도차량의 현가요소 최적화)

  • Park, Chan-Kyoung;Mok, Jin-Yong;Kim, Ki-Whan
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.183-188
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    • 2009
  • The High speed electrical multiple train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project comes in stage of basic design and so, it needs to take some review and analysis the characteristics of suspensions on the view of basic design. The vehicle model for dynamic analysis is made from the concept design model that used for the preliminary design review with Vampire program and it is modeled with three linear secondary dampers and two shear springs separated from the bush elements in previous model. The optimization technique is applied to search the proper range of linear characteristics for the suspension elements to satisfy the stability performance at speed 130m/s (about 460km/h). The results shows there are some optimum points according to the variation of primary and secondary suspension characteristics and it would be useful to make a decision to select the proper suspension elements in the precision design that will be done by the manufacturing company.

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A Study on the displacement characteristics of suspension elements for KTX (고속철도차량 현가계요소 변위특성 연구)

  • Hur H.M.;Kwon S.T.;Lee C.W.;Kim H.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.378-382
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    • 2005
  • The opening of high speed railway upgraded our land transportation speed limit, causing lots of changes including living and culture and also paving the way for stepping up the railway technology. However, it is also true that we had a limit to adopt the existing railway system structured for 150km/h to the new structure requiring a higher speed of approximate 300km/h due to technological, based on the time and experience. More importantly, heading toward a step of operating such a high speed railway system, it has been practically and quickly proposed that the railway needs high speed railway engineering, maintenance technology of parts of the vehicles to have a stable maintenance foundation and localization of major parts. Therefore, this study was intended to research the actual displacement characteristics in runningg on an actual track for the purpose of developing the protective and maintenance technology of springs and dampers, which are core parts among suspension elements of a high speed railway vehicle. For this, it was researched the actual vehicle test and its interpretation centered on primary spring, which is used for the suspension system of a bogie, body-body dampers and body-bogie yaw damper. Also, to analyze the displacement characteristics of suspension system in the actual conditions of high speed railway vehicles, a vehicle‘s dynamic characteristics was analyzed and interpreted. At the same time, a tester for measuring the actual displacement of such suspension elements was designed and attached to actual vehicles, to measure the displacements that occur in running it on the Seoul-Busan line, one of major lines serviced by KTX. The displacement data gained from the test with actual vehicles was analyzed for its displacement distribution depending on the service sections and frequency, with which the valuable data necessary for any potential breakdown or maintenance in the future could be obtained.

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Multibody Dynamic Simulation and Running Characteristics of DMT Freight (다물체 동역학해석을 이용한 DMT 화차의 주행특성 연구)

  • Lee, Seung-Il;Eom, Beom-Gyu;Lee, Hi-Sung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.1
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    • pp.35-41
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    • 2009
  • Through the multibody dynamic simulation, the analysis model of the modalohr freight car of the DMT freight car was developed. By using the developed analysis model, the running dynamic characteristics was inquired through the dynamic analysis about the modalohr freight car. As the running speed and the primary suspension were increased, the lateral and vertical vibration accelerations of the car-body and the bogie were also increased. In case of the lateral vibration acceleration of the car-body, however, review should be considered since it can be influenced by the nonlinear characteristic of the primary suspension. The lateral and vertical vibration of the car-body were generated at the frequency of $2{\sim}3\;Hz$ and $7{\sim}8\;Hz$. And the lateral and vertical vibration of the bogie were generated at the frequency of $25{\sim}35\;Hz$ at the low speed section, $40{\sim}50\;Hz$ at the high speed section.

Transfer Path Analysis on the Passenger Car Interior Noise (승용차 실내소음의 전달경로 해석)

  • 지태한;최윤봉
    • Journal of KSNVE
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    • v.9 no.1
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    • pp.97-102
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    • 1999
  • Structure-borne noise is an important aspect to consider during the design and development of a vehicle. In this work. it was desired to identify the primary paths associated with structure-borne noise generated from the engine and front suspension. An experimental source-path-receiver model was used to characterize the system. A variety of primary sources such as engine. tires or exhaust system generate vibrations of the inner surfaces of the passenger compartment of a vehicle which subsequently radiate noise. The source was characterized by the force acting at the engine-to-body interface. and the path was characterized by pressure over force FRF's. The excitation forces were indirectly determined using dynamic stiffness of rubber mount or the system accelerance matrix. Through these analysis, path contribution diagram which is well expressed primary noise path is obtained.

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A Study on Fatigue Wear Improvement of High Pressure Seal for Tracked Vehicle Suspension (궤도차량 현수장치 고압용 시일의 피로마모 개선 연구)

  • Lee, Yongjun;Kim, Hyeonghyeon;Kim, Kyungro;Koo, Yungseo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.1
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    • pp.12-17
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    • 2017
  • In this paper, causes of wear on high pressure seals for suspension are analyzed, and the result of reproduction test and verification on improved design are described. First, by performing the observation of worn surfaces and its failure analysis, the primary cause of wear on the seals are analyzed. The result of analysis shows that the main failure mechanism of wear is a fatigue wear, and test criteria for failure reproduction are set up with consideration for frequency condition, surface roughness and pressure. Durability comparison test on the condition of low amplitude and high frequency is carried out. And, it is found that the durability of wear on seals by increasing hardness of cylinder and managing for surface roughness is enhanced.

Analysis and Small Scale Model Expriment on the Vertical Vibration of the KT-23 Type Passenger Vehicle (KT-23형 여객 차량의 상하 진동 해석 및 축소모형 실험)

  • 최경진;이동형;장동욱;권영필
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.4
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    • pp.266-273
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    • 2003
  • The purpose of this study is to obtain the effects of the parameters of the suspension system in railway rolling-stock for KT-23 type Passenger vehicle. According to the analysis and the small scale model car test. optimal condition was obtained for the stiffness ratio of secondary spring to primary spring of the suspension system and the mass ratio of the bogie frame to the car body. The analysis of the study shows that if the car body mass is increased or secondary stiffness Is lowered, the vertical vibration level is reduced and the passenger comfort can be improved. Especially, strong peaks are occurred in the frequencies corresponding to the rotational speed of driving axle and vehicle wheel. Hence, in order to obtain the dynamic characteristics through the small scale model car, the driving method of the vehicle on the test bench, rotational characteristics of the wheel and the natural modes of vehicle should be investigated and be modified.

An Experimental Evaluation for an Abnormal Vibration on Running of the High Speed Train (고속열차 주행중 이상진동에 대한 시험적 평가)

  • Yang, Hee-Joo;Woo, Kwan-Je;Son, Byoung-Gu;Seong, Jae-Ho
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2263-2268
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    • 2011
  • THE VIBRATION MODE OF RAILWAY VEHICLE IS DIFFICULT TO FIND OUT THE CHARACTERISTICS OF MOTION DURING THE OPERATION ON THE TRACK BECAUSE THESE HAPPEN TO INDEPENDENCE OR DUPLICATION MOTION CAUSED BY VEHICLE, WHEEL/RAIL INTERACTION, TRACK IRREGULARITY AND FAILURE OF THE SUSPENSION & POWER TRANSMISSION DEVICE ETC. IT IS NAMED AN ABNORMAL VIBRATION THAT THE VIBRATION, WHICH WAS PASSED THE PRIMARY AND SECONDARY SUSPENSION, IS AFFECTED TO THE PASSENGER OR DRIVER WITHOUT DAMPING. THIS PAPER DESCRIBES AN EXPERIENCE EVALUATION TO FIND OUT THE CAUSE OF AN ABNORMAL VIBRATION WHICH WAS HAPPEN AT THE CAB OF POWER CAR IN KTX-SANCHEON TRAINSET WHEN ON RUNNING AT HIGH SPEED ZONE.

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Expriment of the Vertical Vibration for Effect of the Parameter of Stiffness Ratio of the Small Scale Passenger Vehicle (여객차량 현가장치의 강성비 변화에 의한 진동 실험)

  • 최경진;장동욱;권영필;김완두
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.1110-1115
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    • 2002
  • The purpose of this study is to analyze the effects of the parameters of the suspension system in railway rolling-stock for KT-23 type passenger vehicle. According to the results of simulation and the small scale vehicle test. Optimal condition was obtained for the stiffness ratio of the primary spring and secondary spring of the suspension system. When the stiffness ratio was Increased, the vortical vibration was increased on the car body for empty and weight car. The result of this study are stable to use of the optimum parameter of the ride duality of KT-23 type vehicle. Also, it is usefull to development of full scale vehicle dynamomer

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Analysis of the Suspension Characteristics for Next generation High Speed Train on the View of Concept Design (개념적 관점에서 차세대고속철도차량의 현가요소 특성 분석)

  • Park, Chan-Kyoung;Kim, Yong-Guk;Kim, Ki-Whan
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.835-840
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    • 2008
  • Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A vehicle modeling is made of modified Korean High Speed Train bogie model with Vampire program and analyzed the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics. The results would be useful to manage the potential risks in the next stage of basic and precision design that will be done by the manufacturing company.

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