• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.187-187
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• 2004

진공청소기는 가전 제품 중에서 인간의 일상생활에서 꼭 필요한 가전제품의 하나이다. 그러나, 성능 향상을 위한 과도한 회전 속도 때문에 큰 소음을 유발하며 그로 인해서 사용자에게 소음으로 인한 스트레스나 피로누적 등의 큰 불편을 초래하고 있다. 이것은 진공청소기내에 있는 팬 모터가 30000∼35000 rpm으로 고속회전을 통해서 측에 연결되어 있는 임펠러를 회전시켜 공기를 흡입, 배출시키는 일련의 작동을 하면서 여러 가지 진동 및 유체소음을 일으키기 때문이다. 이러한 진공청소기용 팬모터의 소음 저감 연구는 국내외 관련회사 및 연구소에서 활발히 진행되고 있다.(중략)

• Journal of the korean Society of Automotive Engineers
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• v.9 no.3
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• pp.46-54
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• 1987

자동차의 외형을 설계하는 과정에서 미적인 관점을 떠나 역학적으로 고려할 때에는 공기역학이 매우 중요하게 된다. 이 분야에서 연구하는 전문가에게는 잘 알려진 내용이 될지는 모르겠으나 자동차의 설계 및 개발에 종사하는 일반연구자에게는 공기역학에 관한 문헌 및 전문서적 또한 주 위에서 쉽게 얻을 수는 있으나 부담없이 인식되기에는 그리 쉬운 일은 아니다. 이와 관련하여 Car Stying Volume 50+1/2의 별책으로 간행된 특집호에 여러 가지 흥미있는 내용이 기술 설명 되어 있다. 이는 1985년 발행되었으며 일본자동차연구소에 재직중인 무능진리씨가 해설하였다. 이후 본 내용은 여기서 발췌함을 밝혀둔다. 자동차에 관한 공기역확은 주로 다음과 같은 성능 향상을 위하여 필요하다. (1) 주행연료비 절약 (2) 최고속도의 향상 (3) 고속주행시 조종안정성의 향상 (4) 횡풍에서 주행안전성 향상 (5) 엔진이나 제동장치 등의 냉각성능 향상 (6) 바람에 의한 소음의 감소 (7) 환기성능의 향상 (8) 제상성능의 향상 (9) 공기 조화성능의 향상 (10) 먼지 또는 오물의 부착방지 및 억제 (11) 창문 와이퍼의 작동 등이다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.12 s.117
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• pp.1215-1223
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• 2006

A leaf spring suspension has been widely used since it can carry big load and its simplicity. But one major drawback is the poor ride performance because of the friction in the system and the high stiffness coefficient. To overcome these, an air spring suspension can be used. The air spring suspension system can improve the ride of the heavy vehicle significantly and also it can adjust the height to the loading and unloading. The road tests for the truck with the leaf spring suspension and air spring suspension are performed to compare the ride quality of the two systems. To develop the air spring suspension system tailored to the target truck, chassis development procedure using CAE has been applied.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.332-339
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• 2006

A leaf spring suspension has been widely used since it can carry big load and simplicity. But one major drawback is the poor ride performance because of the friction in the system and the high stiffness coefficient. To overcome these, air spring suspension can be used. The air spring suspension system can improve the ride of the heavy vehicle significantly and also it can adjust the height to the loading and unloading. A truck with the leaf suspension system is modified with the air suspension system and the performance of the vehicle is compared using the suggested method. The existing leaf suspension can be replaced with the air suspension system to improve the performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.792-796
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• 2009

Application of air foil bearing (AFB) is widely using to cope with requirements of high speed and high efficiency system at turbo machinery. At same time, a wide variety of AFB design methods are required. In this paper, the AFB design factor influencing the most greatly in bearing performance was selected through theoretical analysis and vibration test was conducted using selected factor. Through this process, AFB system applicable for vehicle turbo machinery was developed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.791-791
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• 2009

Hybrid air-foil magnetic bearing combines two oil free bearing technologies to take advantage of the strengths of each bearing with minimizing each other weaknesses. This paper presents bending mode vibration control of a flexible shaft supported by the hybrid air-foil magnetic bearing. An experiment set-up of a flexible shaft supported by the hybrid air-foil magnetic bearing is built. In order to verify the effectiveness of the hybrid bearing, unbalance responses of the flexible shaft supported by three different bearings: air-foil, magnetic and hybrid bearings are compared. Effect of load sharing between air-foil and magnetic bearings are investigated through changing control gain and offset displacements of magnetic bearing.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.680-683
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• 2005

The wing component model for flutter analysis consisting of stiffness, mass, and aerodynamic model has been constructed based on the full airframe finite element model for 4-seat canard-type small aircraft. A study on wing flutter characteristics has been investigated based on the wing component model constructed using PK method in MSC/NASTRAN for flutter analysis. In addition, wing flutter mechanism for the aircraft under consideration has been analyzed based on the results of normal mode and flutter analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.547-550
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• 2005

In many machines handling lightweight and flexible media, such as automated teller machines and printers, the media must transit an open space. It is important to predict the static and dynamic behavior of the sheets with a high degree of reliability The nonlinear theory of the dynamic elastica has often been used to a nonlinear dynamic deflection model. In this paper, the governing equation is derived and simulated by the finite difference method. The analysis has to include aerodynamic effect for more exact behavior analysis, because the flexible media can be deformed drastically by a little force. Therefore aerodynamic force must be applied to the governing equation. Different results were obtained with and without aerodynamic effect and the resulted show that after contacting circular guide, the directions of flexible media of two cases are different.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.1
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• pp.24-31
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• 2004

Recently, as the marine compressor power is increased, vibration problems on the marine vessel with V/W type reciprocating compressor have been occurred. A research on the balancing of marine V/W type reciprocating compressor has hardly been reported though a number of researches on the balancing of rotating machinery have been conducted. As a V/W type compressor has high capacity with long stroke, compact size and high center of gravity, It is easy to have a vibration problem by a little bit unbalanced force and moment. In this study, calculation methods for balance weight of the V/W type reciprocating compressors, which have different piston weight and asymmetry structure, are formulated. And their reliability were verified by comparing calculated balance weight with the experimental results of the real marine V/W type reciprocating compressors.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.1
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• pp.56-65
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• 2011

A new hybrid mount system is proposed for microvibration control in a high-tech factory. The mount consists of an airspring as a passive device and a piezostack actuator as an active device. The two devices are connected in series. Some numerical simulations and experimental tests are carried out to evaluate isolation performance of the mount system comprising of four proposed hybrid mounts. As a control logic, the specific algorithm is adopted for considering multiple target frequencies of excitation based on a Filtered-X LMS algorithm. The results are compared with isolation performance of the passive airspring mount system. It is confirmed that the proposed hybrid mount system has great performance on microvibration.