• Title/Summary/Keyword: 홴소음

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Design of Low Noise Engine Cooling Fan for Automobile using DACE Model (전산실험모형을 이용한 자동차 엔진 냉각홴의 저소음 설계)

  • Sim, Hyoun-Jin;Park, Sang-Gul;Joe, Yong-Goo;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.5
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    • pp.509-515
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    • 2009
  • This paper proposes an optimal design scheme to reduce the noise of the engine cooling fan by adapting Kriging with two meta-heuristic techniques. An engineering model has been developed for the prediction of the noise spectrum of the engine cooling fan. The noise of the fan is expressed as the discrete frequency noise peaks at the BPF and its harmonics and line spectrum at the broad band by noise generation mechanisms. The object of this paper is to find the optimal design for noise reduction of the engine cooling fan. We firstly show a comparison of the measured and calculated noise spectra of the fan for the validation of the noise prediction program. Orthogonal array is applied as design of experiments because it is suitable for Kriging. With these simulated data, we can estimate a correlation parameter of Kriging by solving the nonlinear problem with genetic algorithm and find an optimal level for the noise reduction of the cooling fan by optimizing Kriging estimates with simulated annealing. We notice that this optimal design scheme gives noticeable results. Therefore, an optimal design for the cooling fan is proposed by reducing the noise of its system.

Computation of Internal BPF Noise of Axial Circulating Fan in Refrigerators (냉장고 내 냉기순환용 축류홴에 의한 내부 블레이드-통과-주파수 소음 예측)

  • Lee, Seung-Yub;Heo, Seung;Cheong, Cheol-Ung;Kim, Seok-Ro;Seo, Min-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.5
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    • pp.454-461
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    • 2009
  • Internal aeroacoustics of an axial fan used for circulating cold air in refrigerators are computed by using the hybrid method where CFD, acoustic analogy and BEM techniques are utilized. The unsteady flow field around the axial fan is predicted by solving the incompressible RANS equations with the conventional CFD techniques. Then, main noise sources are extracted from this unsteady flow field predictions using Acoustic Analogy. Lastly, BPF noise generated from an axial fan are predicted using these modeled sources combined with the tailed Green function techniques, which are numerically solved by the BEM technique. This hybrid model is validated by comparing the prediction with the experiment. Then, parameter studies are carried out, which suggest a capability of the current method as a design tool for the low-noise of the current axial fan system in a refrigerator.

A Study on the Reduction of Discrete Frequency Tones of a Cross-Flow Fan of Air-Conditioners -Studies on the Random Distribution of Fan Blades and the Skewed Stabilizers- (에어컨 용 횡단류 홴의 특정 주파수 소음 성분의 저감 대책에 관한 연구 -날개의 랜덤 배열과 경사진 스태빌라이저에 대한 연구-)

  • 구형모
    • Journal of KSNVE
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    • v.8 no.5
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    • pp.870-878
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    • 1998
  • The cross-flow fan which constitutes a fan-duct system with a stabilizer and a scroll casing is widely used in many air-ventilating and air-conditioning devices. Its ooperating points of high efficiency and loading conditions frequently induce a annoying sharp tonal component of discrete frequency on the noise spectrum, which is open called as a BPF(Blade-Passing-Frequency) noise and degrades the sound quality of the devices. this BPF tone has been one of the defects of the cross-flow fan. This study proposes two methods in order to reduce this tonal noise component, which are the random distributions of the fan blades and the skewed shapes of the stabilizer. The proposed methods are verified by a simple analytical model and are applied in manufacturing the cross-flow fan and the stabilizer samples. Some experiments are carried out to verify the reduction capability of BPF tones of above two schemes and the experimental results are analyzed. The comparison between two method is also carried out.

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Design of Automotive Engine Cooling Fan and Study on Noise Reduction through Modification of System (자동차용 냉각홴의 설계와 시스템 개선을 통한 저소음화 연구)

  • 김병주;강상규;김규영;이재영;이덕호;신동수
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.11
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    • pp.1107-1114
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    • 2004
  • Axial fans are widely used for automotive engine cooling device due to their ability to produce high flow rate to keep engine cool. At the same time, the noise generated by these fans causes one of the most serious problems. Especially, engine cooling fan noise in idle condition of a car is noticeable. Therefore. the high efficient and low-noise fan is seriously needed. When a new fan system is designed, system resistance and non-uniform inflow are the key factors to get the high performance and low noise fan system. In this study, aerodynamic and acoustic calculations are carried out on the automotive cooling fan and system. Effects of various design parameters are studied through the free wake analysis and experiments. Better performance and noise characteristic are obtained for the new design fan using the methodology. Furthermore through the modification of the fan system geometry parameters, the fan system produce more flow rate and become less noisy.

Prediction of internal broadband noise of a centrifugal fan using stochastic turbulent synthetic model (통계적난류합성모델을 이용한 원심홴 내부 광대역 소음 예측)

  • Heo, Seung;Kim, Dae-Hwan;Cheong, Cheol-Ung;Kim, Tae-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.627-632
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    • 2011
  • The internal broadband noise of a centrifugal fan in a household refrigerator is predicted by using hybrid CAA technique based on stochastic turbulent synthetic model. First, the unsteady flow field around the centrifugal fan is predicted using Computational Fluid Dynamics (CFD) method. Then, the turbulent flow field is synthesized by applying the stochastic turbulent synthetic technique to the predicted flow field. The aerodynamic noise sources of the centrifugal fan are modeled on a basis of the synthesized turbulent field. Finally, the broadband noise of the centrifugal fan is predicted using Boundary Element Method (BEM) and the modeled sources. The predicted result is compared with the experimental data. It is found that the predicted result closely follows the experimental data. The proposed method can be used as an effective tool for designing low-noise fans without expensive computational cost required generally for the LES and DNS simulations to resolve the turbulence flow field responsible for the broadband noise.

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Noise Reduction of PDP TV Cooling Fan System through Parameter Analysis (인자 분석을 통한 플라즈마 디스플레이 패널(Plasma Display Panel) 텔레비전에서의 냉각 홴 시스템 소음 저감)

  • Kim, Kyu-Young;Choi, Min-Goo;Lee, Duck-Joo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.2 s.107
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    • pp.107-114
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    • 2006
  • The present experimental study deals with noise reduction and improvements in cooling performance in a plasma display panel (PDP) television (TV). The main ideas of the fan system noise reduction are maintenance of uniform inflow condition and reduction of the system loss, ${\Delta}P.$ The discrete noise is mainly related with the inflow condition therefore removing the structure which distorts inflow makes the discrete noise reduction. The broadband noise in PDP TV is related with the system losses which result from the presence of the fan downstream obstacle, PDP rear case. Through the modification of the distance and preventing the leakage flow between the fan and rear case, we can obtain the system loss and broadband noise reduction. Additionally we can reduce fan rotating speed because of increased flow rate which obtains from the reduction of system loss (resistance). Finally, 4.2 dB(A) noise reduction and $10\%$ increase in flow rate are achieved. From these results, we show that the reduction of system loss is the most effective way of the fan system noise reduction.

Control Performance Evaluation of MR Fan Clutch for Automotive : Experimental Investigation (차량용 MR 홴 클러치의 제어성능 평가 : 실험적 고찰)

  • Kim, Eun-Seok;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.1
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    • pp.51-57
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    • 2010
  • This paper presents temperature control of engine cooling system using a controllable magnetorheological(MR) fan clutch. An appropriate size of MR fan clutch is devised and modeled on the basis of Bingham model. Subsequently, an optimization to determine design parameters such as width of housing is undertaken by choosing the reciprocal of the controllable torque as an objective function. Under consideration of spatial limitation, design parameters are optimally determined using finite element analysis. A sliding mode controller is then designed to control the angular velocity of the MR fan clutch using experimentally determined parameters. The designed controller is experimentally implemented and control performances of the MR fan clutch system are evaluated.

Aerodynamic Performance Enhancement and Noise of Cooling Fans for Driving Motor (전동차용 모터 냉각홴의 공력성능 향상 및 소음특성)

  • Kang, Shin-Hyoung;Park, Tae-Choon;Cho, Nam-Hyo
    • The KSFM Journal of Fluid Machinery
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    • v.1 no.1 s.1
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    • pp.32-40
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    • 1998
  • Aerodynamic performance of a cooling fan of driving motor was enhanced modifying the vane-shroud configuration. Performance of a target model was evaluated to obtain baseline data. The aerodynamic performance and sound pressure level were tested and measured with different numbers of vane of increased length. The tested models show high and stable performance and low values of specific noise level. The long vane-shroud structure induces more stable through flow and decreases the tip leakage flow, which contributes to the increases of performance and efficiency. The sound pressure level increases for the modified model, however, specific noise level decreases.

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A Study on the Vibration Phenomena of the Duct-fan Systems in Fossil Fueled Boilers : Inlet Vortex Induced Excessive Vibration (화력 발전용 보일러 덕트-홴 시스템의 진동현상에 대한 연구 : 입구측 와류에 의한 과대진동 사례)

  • 김철홍;주영호
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.3
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    • pp.194-201
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    • 2003
  • During the operation, fatigue failures and cracks of duct plate due to excessive duct vibration occurred in a fan-duct system of fossil fueled boilers. We measured static pressure variation (pressure pulsation) in the outlet, and also measured vibration at the outlet duct of a centrifugal fan. It was found that strong pressure pulsation caused by the inlet vortex occurred in inlet vane of centrifugal fan in the middle range of vane opening. Thus, excessive duct vibration is caused by strong pressure pulsation. In this Paper, it is shown that the frequency and amplitude of pressure pulsation depend mainly on vane opening and are compared with duct vibration. Also, effective solution for reducing pressure pulsation and vibration are presented.

A study on Low-Noise and High-Efficiency Sirocco Fan Development (저소음 고효율 시로코 홴 개발에 관한 연구)

  • Park, Kwang-Jin;Lee, Sang-Hwan;Son, Byung-Jin
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.2 s.3
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    • pp.46-56
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    • 1999
  • This study is on the performance prediction and design of a sirocco fan. Slip coefficient is very important factor for the performance analysis of a centrifugal-type fan. Because generally used slip coefficient equations of backward curved centrifugal fan are not appropriate for forward curved sirocco fan, in this study a proper slip coefficient equation for a sirocco fan is suggested. Using this equation performance prediction program for sirocco fan is composed of and also included the total noise prediction that include the turbulent noise at the fan inlet and boundary layer noise. A comparison between the values obtained from performance prediction program and experimental values shows that the program predicts the sirocco fan performance in a practical rate.

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