• 제목/요약/키워드: Cross-flow Fan

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등/부등피치 횡류홴의 유동 소음 특성 (Flow Induced Noise Characteristics of the Cross Flow Fan with Uniform/Random Pitch Blades)

  • 조용;문영준;박진무
    • 설비공학논문집
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    • 제13권7호
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    • pp.621-626
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    • 2001
  • The flow induced noise of the cross-flow fan with uniform/random pitch blades is predicted by computational methods. With the time dependent surface pressure data obtained by solving the incompressible Navier-Stokes equations in moving coordinates, the acoustic pressure is predicted by the Ffowcs Williams-Hawkings equation. The positions of the blade noise source are identified through an investigation of the acoustic pressure history induced by one blade, and it is confirmed that the dominant noise source is near the stabilizer. Since the acoustic pressure of the random pitch fan fluctuates according to the blade passin, the dominant BPF noise of the uniform pitch fan is modulated into some reduced discrete noises which have multiples of a 50Hz difference from BPF.

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상용 CFD 코드를 이용한 횡류홴 공력소음 특성 해석 (Analysis of the Aeroacoustic Characteristics of Cross-Flow Fan Using a Commercial CFD Code)

  • 전완호;정문기
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.289-294
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    • 2002
  • In this study, performance, flow characteristics and noise of a cross-flow-fan system, used in indoor unit of the split-type air conditioner, were predicted by computational simulation. Triangular elements were used to mesh the calculation domain and quadrilateral elements were attached to the blade surfaces and walls to enhance the simulation quality. The unsteady incompressible Wavier-Stokes equations were solved using a sliding mesh technique on the interface between rotating fan region and the outside. Two stripes of velocity stream inside the cross-flow-fan were shown - the one was due to the eccentric vortex and the other was due to the normal entrance flow. As the flow rate increased, the center of the eccentric vortex moved toward the inner blade tip and rear-guide, and the exiting flow still had velocity variation along the stabilizer, which can increase the noise level. The acoustic pressure was calculated by using Lowson's equation. From the calculated acoustic pressure, it was found that the trailing edge is a dominant of acoustic generation.

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실험에 의한 CROSS FLOW FAN 소음 분석 (Experimental study on the design parameter effect on the noise in the cross flow fan)

  • 안철오;류호선
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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    • pp.615-620
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    • 1997
  • The flow rate and the noise level of 18 cross flow fans were measured to analyze the effect of design variables on these and to finally find the optimal design value. These data were analyzed by the Taguchi method and the neural network. The optimal values obtained by the neural network showed good agreements with that by the Taguchi method. The effects of eight design variables on the fan performance and the noise were evaluated and discussed.

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스태빌라이져 위치 및 리어가이더 형상변화에 따른 횡류홴의 성능특성 연구 (Performance of a Cross-Flow Fan with Various Stabilizer Positions and Rearguider Shapes)

  • 김동원;김형섭;윤태석;박성관;김윤제
    • 한국유체기계학회 논문집
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    • 제7권4호
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    • pp.7-15
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    • 2004
  • The design point of the cross-flow fan is generally based on the region within low static pressure and high flow rate. It relatively makes high dynamic pressure at low speed because a working fluid passes through an impeller blade twice. However, it has low static pressure efficiency between $30\%$ and $40\%$ because of relative high impact loss. The purpose of this study is to research the reciprocal relation among each parameter. Experiments and numerical analyses are conducted on effects of a stabilizer and a rearguider on performance analysis of a cross-flow fan. Two-dimensional, unsteady governing equations are solved using FVM, PISO algorithm, sliding grid system and standard $k-{\epsilon}$ turbulence model. Experiments are also carried out to estimate the performance of the modeled cross-flow fan. It is clarified that the rearguider of Archimedes type has excellent results for the most part.

리어가이더 곡률반경에 따른 룸에어콘용 관류홴의 공력성능에 대한 실험적 연구 (Experimental Study on the Aerodynamic Performance of a Cross-Flow Fan for the Various Curvature Radius of a Rear-Guider for a Room Air-Conditioner)

  • 김장권;오석형
    • 동력기계공학회지
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    • 제17권4호
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    • pp.36-44
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    • 2013
  • The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. Also, these factors are given to the various diameter ratio between a basic circle and a impeller. The static pressure and the flowrate of a cross-flow fan were measured with a fan-tester. It could be found that the useful design factors with a good aerodynamic performance exist in the certain assembly conditions of an indoor RAC. Therefore, it could be known that a new published patent determining the easy design of an indoor RAC can be applied in a variety of goods.

이중 블레이드 팬이 장착된 진공청소기 흡입 노즐내 유로 유동 소음 및 팬 성능 해석 (Numerical Analysis of Flow-Induced Noise and Fan Performance in Suction Nozzle of a Vacuum Cleaner with a Double-Blade Fan)

  • 박이선;손채훈;이성철;오장근
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.2632-2637
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    • 2007
  • Rotary performance and flow resistance induced by each element in suction nozzle of a vacuum cleaner with a double-blade rotary fan are investigated numerically and its relation with flow-induced noise and rotary performance is examined. Flow resistance and vorticity in suction nozzle are calculated and it is found that they are closely related with flow-induced noise. Gap between double blades, adoption of cross-flow fan, enlargement of flow inlet area, and optimization of blade number are tested for noise reduction. Finally, the effects of each method are verified experimentally. It is found that several combinations of the proposed methods can be adopted for noise reduction although the degree of reduction is not much.

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횡류홴 설계 인자들의 성능/소음 특성 해석 및 최적화 (Analysis on Performance and Noise Characteristics of the Design Parameters of a Cross-Flow Fan and its Optimization)

  • 조용;문영준;곽지호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.767-770
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    • 2002
  • The performance and noise characteristics of the design parameters of a cross-flow fan are investigated by computational methods. The incompressible Wavier-Stokes equations in moving coordinates are time-accurately solved for obtaining the pressure fluctuations due to the aerodynamic interactions between the impeller blades and the stabilizer, and sound pressure is then computed by the Ffowcs Williams-Hawkings equation. Design parameters of the cross-flow fan include blade setting angle, exit-diffusion angle, and stabilizer installation angle. Also, an optimization of the aforementioned design parameters has been peformed using the Taguchi method.

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비정렬 유한 체적법을 이용한 횡류홴 유동장 해석 (Prediction of Cross Flow Fan Flow Using an Unstructured Finite Volume Method)

  • 강동진;배상수
    • 한국유체기계학회 논문집
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    • 제8권3호
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    • pp.7-15
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    • 2005
  • A Navier-Stokes code has been developed to simulate the flow through a cross flow fan. It is based on an unstructured finite volume method and uses moving grid technique to model the rotation of the fan. A low Reynolds number turbulence model is used to calculate eddy viscosity. The basic algorithm is SIMPLE. Numerical simulations over a wide range of flow rate aye carried out to validate the code. Comparison of all numerical solutions with experimental data confirms the validity of the present code. Present numerical solutions show a noticeable improvement over a previous numerical method which is based on a model of body force to simulate the rotation of the impeller.

비정상 점성 유동 해석에 의한 부등피치 횡류홴의 이산소음 주파수 변조 특성 예측 (Prediction of Frequency Modulation of Discrete Noise for Random Pitch Cross-Flow Fans by Unsteady Viscous Flow Computations)

  • 조용;문영준
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.658-664
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    • 2002
  • Unsteady flow characteristics and associated blade tonal noise of a cross-flow fan are predicted by a computational method. The incompressible Navier-Stokes equations are time-accurately solved for obtaining the pressure fluctuations between the rotating blades and the stabilizer, and sound pressure is predicted using Curie's equation. The computed fan performance is favorably compared with experimental data, and also indicates that the performance is not significantly altered by the random pitch effect at ${\phi}>0.4$. In the present study, the narrow-band noise characteristics of three impellers with a uniform and two random Pitch (type-A and-B) blades are compared by the SPL (Sound Pressure Level) spectra, and their frequency modulation characteristics of the BPF (Blade Passing Frequency) noise are also discussed.

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비정상 점성 유동 해석에 의한 부등피치 횡류홴의 이산소음 주파수 변조 특성 예측 (Prediction of Frequency Modulation of Discrete Noise for Random Pitch Cross-Flow Fans by Unsteady Viscous Flow Computations)

  • Yong Cho;Young J. Moon
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.366.2-366
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    • 2002
  • Unsteady flow characteristics and associated blade tonal noise of a cross-flow fan are predicted by a computational method. The incompressible Wavier-Stokes equations are time-accurately solved for obtaining the pressure fluctuations between the rotating blades and the stabilizer, and sound pressure is predicted using Curie's equation. The computed fan performance is favorably compared with experimental data, and also indicates that the performance is not significantly altered by the random pitch effect at ø〉0.4. (omitted)

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