• 한국항공우주학회지
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• 제36권2호
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• pp.156-162
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• 2008

본 연구에서는 자유후류기법을 이용하여 복합재 무힌지 로터 블레이드에 대한 정적 공탄성 해석을 수행하였다. 1차원 보의 거동을 해석하기 위하여 대변형 보 이론이 적용되었다. 또한, 복합재 블레이드의 단면 해석을 위하여 이방성 보 이론이 적용되었다. 공탄성 해석에 필요한 공력 하중들은 와류격자법(VLM)에 기초한 3차원 공기력 모델을 통하여 계산되었다. 이때, 정지비행시의 후류는 순차적 시간 적분 자유후류법을 통하여 묘사되었다. 복합재 무힌지 로터 블레이드의 정적 변형에 대한 해석 결과를 2차원 준정상 공기력과 경험후류기법을 통한 해석 결과들과 비교하여 살펴보았다. 결과적으로, 정지비행시 후류 효과에 의해 정적 변형의 결과가 달라짐을 확인하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.954-960
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• 2001

Axial fans are widely used in heavy machines due to their ability to produce high cooling of engines. At the same time. the noise generated by these fans causes or serious problems. This work is concerned with the low noise technique of discrete. The prediction model. which allowed the calculation of acoustic pressure at the frequency and it's harmonics, has been developed by Farrasat and the Helmholtz-Kir. The newly developed Helmholtz-Kirchhoff BEM for thin body is used to calculate the sound field of the fan that is located in a engine room. To calculate the unsteady resultant force over blade. Time-Marching Free-Wake Method are used. The fan noise of fan sys unsymmetric engine-room is predicted. In this paper. the discussion is confined to and discrete noise of axial fan and front Part of engine room in heavy equipments.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.264-269
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• 2001

Axial fans are widely used in household electrical appliances due to their easy usage and high flow rate for cooling capacity. At the same time, the noise generated by these fans causes one of serious problems. In order to calculate the noise of a fan, we develop the software IFD - Intranet Fans Design. With this software we can design, analysis the performance and predict the noise of fan. The prediction model, which allowed the calculation of acoustic pressure at the blade passing frequency and it's higher harmonic frequencies, has been developed by Lowson's equation. To calculate the unsteady resultant force of the blade, time-marching free-wake method is used. The objective of this study is to calculate the effects of number of blades, rotating velocity, and sweep angle on the noise of fan..

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.388-395
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• 2000

Axial fans are widely used in heavy machines due to their ability to produce high flow rate for cooling of engines. At the same time, the noise generated by these fans causes one of the most serious problems. This work is concerned with the low noise technique of discrete frequency noise. The prediction model, which allowed the calculation of acoustic pressure at the blade passing frequency and it's harmonics, has been developed by Farrasat. This theory is founded upon the acoustic radiation of unsteady forces acting on blade. To calculate the unsteady resultant force over the fan blade. Time-Marching Free-Wake Method are used. The ideas of low noise technique are obtained from Blade-Momentum Methods. In this paper, the discussion is confined to the performance and discrete noise of axial fan in heavy equipments.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.106-112
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• 2000

Axial fans are widely used in heavy machines due to their ability to produce high flow rate for cooling of engines. At the same time. the noise generated by these fans causes one of the most serious problems. This work is concerned with the low noise technique of discrete frequency noise. The prediction model. which allowed the calculation of acoustic pressure at the blade passing frequency and it's harmonics. has been developed by Farrasat. This theory is founded upon the acoustic radiation of unsteady forces acting on blade. To calculate the unsteady resultant force over the fan blade. Time-Marching Free-Wake Method are used. The fan noise of fan system having unsymmetric engine-room is predicted. In this paper, the discussion is confined to the performance and discrete noise of axial fan and front part of engine room in heavy equipments.