• Title/Summary/Keyword: Air-guide

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Studies on the Cooling Performance of Front End Module for Pedestrian Protection (보행자 보호용 프론트 엔드 모듈(FEM)의 냉각성능에 관한 연구)

  • Shin, Yoon-Hyuk;Kim, Sung-Chul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.6
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    • pp.67-72
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    • 2012
  • Novel Front End Module(FEM) with improved pedestrian protection is very important to reduce the severity of pedestrian injury. The FEM needs to have enough space from hood to absorb the energy from any pedestrian collision. In this study, the cooling performance of the FEM to cool the engine was investigated under 25% height reduction. The results indicated that the cooling performance analysis was about 86% level compared to that of the conventional FEM. Also, good qualitative agreement between CFD predictions and experimental measurements was found. This FEM needs the cooling performance enhancement for changed air flow path at the frontal part of vehicle. Therefore, we showed an improved performance using air guide setup and shape modification under the high load condition.

Optimal Flow Design of High-Efficiency, Cold-Flow, and Large-size Heat Pump Dryer (히트펌프를 이용한 고효율 냉풍 대형 건조기 유동 최적설계)

  • Park, Sang-Jun;Lee, Young-Lim
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.5
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    • pp.547-552
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    • 2011
  • Drying process, corresponding to a final process in the area of food engineering, requires a lot of heat energy. Thus, the energy efficiency is very important for dryers. Since the energy efficiency of heat pump dryers is much higher compared to that of electric dryers or other types of dryers, most of large-capacity dryers are adopting heat pump. In this study, shapes, positions and number of air-circulating fans, guide vanes, air inlet, outlet and top separator were varied for optimization of the flow of a large-capacity heat pump dryer. In addition, fans were modelled with performance curves and porous media were assumed for foods and heat exchangers. The simulation results were applied to the 12-ton dryer and the velocity distributions were experimentally examined. Finally, uniform drying in time was successfully accomplished through frozen pepper experiment.

A levitation-controller design for EMS (Electromagnetic Suspension) (상전도 흡인식 자기부상제어기 설계)

  • Sung, Ho-Kyung;Jho, Jeong-Min;Lee, Jong-Moo;Nam, Yong-Youn;Shin, Byung-Cheon
    • Proceedings of the KSR Conference
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    • 2006.11a
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    • pp.171-180
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    • 2006
  • The EMS system requires a very delicate suspension control to maintain constant air-gap between the magnet and the guide-way rail. To maintain a constant air-gap with attraction force, the EMS system dynamics is changed according to uncertainties and disturbances, and it also requires reliability against component failures. Since uncertainties and component failures are frequently caused in EMS system, it is very important to develop the robust and reliable control system. In this paper, we consider the design problem for robust and reliable controller in the presence of uncertainties and component failures.

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The Design of Hydraulic Brake Control System used on Blending Brake Function (혼합제동기능을 이용한 유압제동 제어시스템 설계)

  • Lee, Woo-Dong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.12
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    • pp.1809-1812
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    • 2013
  • The bogie of monorail vehicles applies rubber wheel system not steel wheel system. In addition, The structure of the bogie is very complicated because vehicle operates on the elevated road and vehicle drives with wrapping the guide way. When the monorail vehicle applies air brake system, lower device of vehicle may be complex and some devices may be limited. On the other hand, hydraulic brake equipment is compact and not weighing. Braking force is also outstanding compared with air brake so the hydraulic brake equipment is suitable for monorail vehicle. Also urban transit system such as monorail, applies mixed system both friction brake and electric brake in order to save electric energy. But application case of hydraulic brake in the country is very rare because hydraulic brake have difficulty in satisfaction of control requirement and maintenance. Therefore, this study suggests ways to design hydraulic brake system with blending brake for monorail vehicle and applies the ways to future monorail.

Structural Characteristics Analysis of a High-Speed Horizontal Machining Center with Built-in Motor and Linear Motors (냉장형 모터와 리니어 모터를 적용한 초고속 수평형 머시닝센터의 구조 특성 해석)

  • 김석일;조재완
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.326-333
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    • 2004
  • This paper presents the structural characteristics analysis of a high-speed horizontal machining center with spindle speed of 50, 000rpm and feedrate of 120m/min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil-jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motor and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guide. The structural analysis model of the high-speed horizontal machining center is constructed by the finite element method, and the validity of structural design is estimated based on the structural deformation of the high-speed horizontal machining center and spindle nose caused by the gravity and inertia forces.

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Evaluation and Quantification on the Sources of Uncertainty for Quality Assurance of the Air-Pollution Monitoring Stations (대기오염측정망의 측정 품질 보증을 위한 불확도 요소의 파악과 정량화)

  • 우진춘;문동민;김현호;임종명;이진홍;홍유덕;한진석;이석조
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.121-122
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    • 2003
  • 현재, 대기 환경 자료의 정확한 분석을 위하여 정부와 지자체는 여러 종류의 대기 오염 측정망을 설치하여 운영하고 있다. 측정망으로부터 산출된 이러한 자료들의 품질은 대기 환경 학자 및 전문가들은 물론이고 일반 국민들의 일상적인 활동에도 중요한 영향을 미치고 있기 때문에, 측정 결과의 정화한 이해와 사용을 위한 품질 보증이 매우 중요한 실정에 있다. 그러나, 국제적인 수준의 품질 보증이 이루어지기 위해서는 측정 실험실의 인증 요건(ISO 17025) 및 측정 불확도 표기(ISO Guide) 등에 관한 국제적인 규격들의 적용이 매우 엄격하게 요구되고 있는 실정이다. (중략)

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Simplification of Turbine Structure and Performance Improvement of Micro Cross-Flow Hydropower Turbine (마이크로 관류수차의 구조 간소화 및 성능향상)

  • Kurokawa, Junichi;Choi, Young-Do;Zhao, Linhu
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.819-824
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    • 2005
  • Recently, micro hydropower attracts attention because of its clean, renewable and abundant energy resources to develop. However, suitable turbine type is not normalized yet in the range of micro hydropower and it is necessary to study for the effective turbine type. Moreover, relatively high manufacturing cost by the complex structure of the turbine is the highest barrier for developing the micro hydropower turbine. Therefore, a cross-flow turbine is proposed for micro-hydropower in this study because of its simple structure and high possibility of applying to low head. The purpose of this study is to further simplify the turbine structure and improve the performance, A guide vane is removed and the runner chamber is made compact using a new air supply method. The results show that the efficiency of the turbine is improved in a wide operating range and the size of the turbine is remarkably reduced.

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Excavator cabin modeling for noise analysis using SEA (SEA 를 이용한 굴삭기 차실 소음 모델 개발)

  • Kang, Junghwan;Park, Soodong;Kwak, Hyungtaek;Kim, Jooho;Kim, Seongjae;Kim, Indong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.156-158
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    • 2014
  • The interior noise of an excavator cabin is important factor related to operation efficiency. For analyzing the cabin air-borne sound, the SEA cabin model was developed using VA One. Analysis result using measured surface SPL of cabin was compared with test data. And the noise reduction guide of cabin was suggested with contribution and sensitivity analysis results of major design variables using developed SEA analysis.

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Flow Noise in the Outdoor Unit of an Air-conditioner (에어컨 실외기에서의 유동소음)

  • 이승배;이재환;김휘중;최진규;진성훈;박윤서
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.594-601
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    • 1997
  • Propeller fans are commonly equipped in outdoor units of air-conditioners to provide effective cooling in a dried heat exchanger. A new design technique was developed to satisfy requirements of aerodynamic and aeroacoustic performance, which employs the intersection method of two cylinders for mean camber line. Three proto-types of propeller fan including Palm-Shaped, Highly-Swept(PSHS) fan (proto 3)were not only to provide low lift forces for dipole sound, but also to reduce the organized tip vortices interacting with the fan guide causing narrow-banded rotating instabilities. Cross-correlation technique was applied to study flow noise source characteristics for three proto-type fans designed. The cross-correlations between a microphone at far field and a hot-wire sensor at near field show that flows near hub region of proto 3 fan are less organized and the flow structures especially at high flow rate coefficients for proto 3 fan are less correlated with noise generated than other proto-types fans.

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