• 제목/요약/키워드: unbalance mass

검색결과 155건 처리시간 0.021초

엔진 관성력과 피칭모멘트 저감을 위한 밸런스샤프트의 동역학 설계 (Dynamic Analysis Design of Balance Shaft for Reducing Engine Inertia Force and Pitching Moment)

  • 김병준;부광석;김흥섭
    • 한국융합학회논문지
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    • 제13권4호
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    • pp.307-313
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    • 2022
  • 차량 실내소음이 엔진의 고출력화와 경량화로 인해 더욱 심각해져 엔진진동의 저감의 중요성이 높아지고 있다. 최근 엔진진동 저감의 대표적인 방법으로 밸런스샤프트 부착이 제시되고 있다. 밸런스샤프트는 피스톤과 콘로드 등의 왕복운동에서 발생하는 진동을 임의의 편심질량을 이용하여 상쇄시키는 장치이다. 따라서 밸런스샤프트는 연비향상 및 차량의 승차감을 동시에 향상시킬 수 있다. 본 논문은 엔진구조로 인해 발생하는 관성력을 유도하고 이를 상쇄하기 위한 밸런스샤프트의 불평형량과 형상을 제시한다. 제시된 두가지 형상의 밸런스샤프트를 ADAMS 다물체동역학 모델로 구현하고, 이를 동역학 시뮬레이션을 통해 실제 거동상태에서의 관성력의 저감을 확인하였다.

고기동 항공기 하부 장착 파드의 공력 및 관성하중 분석 연구 (Analyses on Aerodynamic and Inertial Loads of an Airborne Pod of High Performance Fighter Jet)

  • 이재인;신진영;조동현;정형석;최태규;이종훈;김영호;김시태
    • 한국군사과학기술학회지
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    • 제25권1호
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    • pp.9-22
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    • 2022
  • A fighter performing a reconnaissance mission is equipped with a pod that drives optical/infrared sensors for acquiring and identifying target information on the lower part of the fuselage. Due to the nature of the reconnaissance mission, the fighter performs high speed evasive maneuvers, and the resulting load should be considered importantly for the development of the pod. This paper concerns a numerical investigation into the inertial and aerodynamic loads of the airborne pod of high performance aircrafts. For the aerodynamic load analysis, the pylon and pod shapes are added to the fighter 3D model, and the commercial software was used for static and dynamic analysis. Considering the practical mission conditions, the common/extreme conditions were established respectively in the static and dynamic situations of pods and the driving torque could be tripled under dynamic conditions. In the analysis of inertia load, a 3-DOF model considering roll and turning maneuvers was derived by the Lagrangian method, and then the numerical integration method was applied to the analysis. As a results, it was conformed that the inertia load was generally induced at a low level compared to the aerodynamic load, but depending on the unbalance mass condition of the pod, the inertia load cannot be negligible.

4MW급 풍력발전기용 요 감속기 설계 (Yaw Gearbox Design for 4MW Class Wind Turbine)

  • 이형우;김인환;이재신
    • 융합정보논문지
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    • 제12권2호
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    • pp.142-148
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    • 2022
  • 본 논문은 풍력발전기용 요 감속기를 경량화하여 유한요소해석과 위험속도해석을 통해 안정성검증을 하였다. 제품의 경량화는 엔진의 효율을 높일 수 있으며, 부품의 소재를 절약하여 경제적 이득을 취할 수 있다. IEC 61400-1에서 제시한 풍력발전기 부품의 안전율 1.3이상을 목표로 풍력발전기용 요 감속기를 경량화하였다. 위상 최적화를 수행한 캐리어를 유한요소해석을 수행하여 안전율을 나타냈고, 하우징과 최적화한 캐리어를 MASTA11을 활용하여 작성한 풍력발전용 요 감속기 기어트레인 모델과 부분구조합성법으로 연결하여 고유 모드와 고유진 동수를 파악하여 질량불평형과 치통과 주파수에 대하여 위험속도해석을 수행하였고, 캠벨 선도(Campbell Diagram)를 작성하여 안정성 검증을 하였다.

대형 LCD 패널 제조용 복합재 롤러의 회전체 동역학 해석 (Rotordynamic Analyses of a Composite Roller for Large LCD Panel Manufacturing)

  • 박효근;최진호;권진회;이영환;양승운;김동현
    • Composites Research
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    • 제19권6호
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    • pp.8-15
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    • 2006
  • 본 연구에서는 대형 LCD 패널 제조용 복합재 롤러에 대한 3차원 회전체 동역학 해석을 수행하였다. 전산해석은 로터시스템의 회전에 의한 자이로스코픽 영향을 고려한 일반적인 유한요소법에 근거하고 있다. 본 연구에서는 유럽의 범용 상용 유한요소해석 프로그램인 SAMCEF를 활용하였으며 이는 전문적인 로터해석 모듈을 포함하고 있다. 전산해석 기법의 검증을 위해 베어링 지지된 2중 회전축 로터 모델에 대한 해석 및 비교결과를 제시하였다. 설계된 복합재 롤러 모델에 대한 상세 유한요소 모델을 구축하였으며, 중력 효과를 고려한 전산해석을 통하여 실제 운용환경에서의 진동특성을 고찰하였다. 이의 결과로 다른 회전조건에 대한 로터 안정성 선도 및 불평형 응답에 대한 결과들을 제시하였다.

피부병의 형상의학적 치료 (Treatment of Skin Diseases in Hyungsang Medicine)

  • 석민희;황원덕;정행규;이용태
    • 동의생리병리학회지
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    • 제18권3호
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    • pp.646-669
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    • 2004
  • By treating skin diseases with Hyungsang medicine and reviewing the clinical cases of them through classifying skin diseases into general care and into Hyungsang medical care, the writer came to the conclusion as followings. The skin is a house of Kyungnak, and it' s a place which Ki comes in and out, which human body controls conditions of his physiological function and which doctors can make a diagnosis from seeing it. The skin is subject to lung and large intestine in the point of organ, but in the point of movement, to spleen and stomach. Skin diseases come from unbalance of Ki and Hyul, mostly from fever in blood and also from Dam, Wind, Dampness and Dryness because of including fire. Generally skin diseases are treated according to classifying into distinctive symptoms, region, cause or time being occurred, and concomitant symptoms. After being divided into man and woman, age and youth, fatness and leanness, Jung Ki Shin Hyul type, visceral figures, Yukkyung shapes on Hyungsang medicine method, the remedy of skin diseases which is combined common meditation with Hyungsang medical method is efficacious. In distinguishing into man and woman, age and youth, man gets sick mainly by drinking liquor and exhausting Jung, woman is taken ill generally by indigestion and Damwha, especially by drinking liquor. Young child gets ill mostly from inherent weakness, but in many cases he is occurred by disturbed digestion, so he must be taken care of ingesting food. The aged becomes ill from weakening, so he must be treated according to reasons of diseases. To fatness and leanness, skin diseases are showed symptoms by weakened Yang, insufficient Yin or excess fever on the theory of upper and lower parts, by unbalance of Ki and Hyul on the theory of left and right, by Dryness and Dampness on the theory of front and rear and by insufficiency of vitality and combined fever on the theory of inside and outside. Therefore doctors must cure the symptoms according to the theory of upper and lower, left and right, front and rear and inside and outside. In type of Jung Ki Shin Hyul, the balances between Jung-Hyul and Shin-Ki are important points. Concretely Jung type comes to easily shortage of Jung or gathering abnormally Dampness and Dam, Ki type is easy to make a mass with Ki or to be deficient of Ki, Shin type comes to press seven emotions togather or to be insufficient of Yin and fever inside, and Hyul type is inclined to be deficient of Hyul and to become feverish or to be deficient of Ki. Therefore on the ground of the above reasons skin diseases come into existence. Inclusively in Jung-Hyul type , Ki must be moved on the base of full Jung-Hyul, so Wukmijiwhangtang or Samultang is prescribed basically. In Shin-Ki type , Jung-Hyul is saved on the base of moving Ki, so Hyangsosan or Yijintang is the proper prescription. Considering the visceral figures, doctors judge for diagnosis and remedy by putting together the elements, that is, great and small sizes of a set of features (eye, ear, mouth, nose), color and temper. The yukkyung types are classified according to many or few of Ki-Hyul, and then skin diseases appear by being inclined toward one side between Ki and hyul, or among the six atmospheric elements(wind, cold, heat, dampness, dryness, and fire). Especially because Yangmyung type is full of much Ki and Hyul, and also has much fever in stomach, he gets skin symptoms frequently. So his prescription is based on taking off fever in stomach, and also he must be careful about regimen certainly.