• Title/Summary/Keyword: Cross-flow Fan

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Analysis of the aeroacoustic characteristics of cross-flow fan using commercial CFD code (상용 CFD코드를 이용한 횡류홴 공력소음 특성 해석)

  • Jeon, Wan-Ho;Gi, Jeong-Mun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.334.1-334
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    • 2002
  • In this study, a cross-flow fan system used in indoor unit of the split-type air conditioner is analyzed by computational simulation. A commercial CFD code - Fluent - is used to calculate the performance and its unsteady flow characteristics. The unsteady incompressible Wavier-Stokes equations are solved using a sliding mesh technique on the interface between rotating fan region and the outside. The acoustic pressure is calculated by using Ffowcs-Williams and Hawkings equation. (omitted)

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

  • Kang Dong-Jin;Bae Sang-Su
    • The KSFM Journal of Fluid Machinery
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    • v.9 no.4 s.37
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    • pp.27-35
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    • 2006
  • 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 are 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.

ANALYSES ON FLOW FIELDS AND PERFORMANCE OF A CROSS-FLOW FAN WITH VARIOUS SETTING ANGLES OF A STABILIZER

  • Kim D. W.;Kim H. S.;Park S. K.;Kim Youn J
    • Journal of computational fluids engineering
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    • v.10 no.1
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    • pp.107-112
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    • 2005
  • A cross-flow fan is generally used on the region within the low static pressure difference and the high flow rate. It relatively makes high dynamic pressure at low rotating speed because a working fluid passes through an impeller blade twice and blades have a forward curved shape. At off-design points, there are a rapid pressure head reduction, a noise increase and an unsteady flow. Those phenomena are remarkably influenced by the setting angle of a stabilizer. Therefore, it should be considered how the setting angle of a stabilizer affects on the performance and the flow fields of a cross-flow fan. It is also required to investigate the effect of the volumetric flow rate before occurring stall. Two-dimensional, unsteady governing equations are solved using a commercial code, STAR-CD, which uses FVM. PISO algorithm, sliding grid system and standard k - ε turbulence model are also adopted. Pressure and velocity profiles with various setting angles are graphically depicted. Furthermore, the meridional velocity profiles around the impeller are plotted with different flow rates for a given rotating speed.

Analysis of Flow Distribution around Room Air Conditioner Using PIV Technique (PIV기법을 이용한 룸에어컨 주변 유동 분포 해석)

  • Lee, A-Mi;Han, Kyu-Il;Kim, Dong-Won;Na, Seon-Uk;Joo, Jae-Man;Ko, Han-Seo
    • 한국가시화정보학회:학술대회논문집
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    • 2006.12a
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    • pp.131-134
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    • 2006
  • Whole flow fields of a room air conditioner (RAC) have been visualized by a Particle Image Velocimetry (PIV) technique to analyze the flow structure by various inlet and outlet angles, and to control an eccentric vortex which affects an efficiency and noise of the RAC. A test model with 5 stages of a cross flow fan has been manufactured and a transparent acryl has been installed at the side of the test model for the PIV experiment. The inlet and outlet flows and the flow inside the cross flow fan have been analyzed by varying the inlet grill angles and outlet blade angles. The movement of the eccentric vortex has been investigated experimentally by developing the measurement technique for the inner flow field of the cross flow fan, and the relationship between the control of the eccentric vortex and the inlet and outlet angles has been confirmed in this study.

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Experimental Study on the Aerodynamic Performance of a Cross-Flow Fan for the Various Leading Angles of a Rear-Guider for a Room Air-Conditioner (리어가이더 선단각도에 따른 룸에어콘용 관류홴의 공력성능에 관한 실험적 연구)

  • Kim, Jang-Kweon;Oh, Seok-Hyung
    • Journal of Power System Engineering
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    • v.17 no.3
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    • pp.35-43
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    • 2013
  • Generally, the chassis of an indoor RAC is composed of a rear-guider and a stabilizer. The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of the chassis of an indoor RAC. The purpose of this paper is to select the optimum design factors through the aerodynamic performance of a cross-flow fan. The design factors are the leading angle of a rear-guider (${\theta}_1$), a stabilizer setup angle(${\theta}_2$), a rear-guider clearance(${\epsilon}_1$), and a stabilizer clearance(${\epsilon}_2$), respectively. As a result, the optimum design factors of an indoor RAC can be presented as a combination of ${\theta}_1=33^{\circ}$, ${\theta}_2=55^{\circ}$, ${\epsilon}_1=6{\sim}8mm$, and ${\epsilon}_2=7mm$ through the analysis of a static pressure coefficient and a static pressure efficiency.

An Experimental Study of the Influences of Basic Design Parameters on the Performance and the Noise Characteristics of Cross-flow Fans (직교류 홴의 설계인자가 성능 및 소음 특성에 미치는 영향에 대한 실험적 연구)

  • 구형모
    • Journal of KSNVE
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    • v.10 no.3
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    • pp.430-436
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    • 2000
  • The cross-flow fans have been widely used to constitute the air moving systems in many air-ventilating and air-conditioning units. The cross-flow fan system has many design parameters which have crucial influence on the performance and the noise characteristics of the units. As a result there are many difficulties in the design stage of the system and the general design guide has not been sufficiently established yet. This study presents the experimental results of the parametric investigation of some chosen design parameters which are directly related to the shape of the stabilizer the profile of the scroll casing and the diffusion angle of the flow exit. The results are expressed in terms of the fan performance and the specific sound pressure level characteristics. Some parameters have been found to have crucial effects on the system performance/noise characteristics and should be considered with care in the design stage.

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Experimental Study on the Three Dimensional Unsteady Flow in a Counter Rotating Axial Flow Fan (엇회전식 축류팬의 3 차원 비정상 유동에 관한 실험적 연구)

  • Park, Hyun-Soo;Cho, Lee-Sang;Kang, Hyun-Koo;Cho, Jin-Soo
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.822-827
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    • 2003
  • Experiments were done for the three dimensional unsteady flow in a counter rotating axial flow fan under stable operating condition. Flow fields in a counter rotating axial flow fan were measured at cross-sectional planes of the upstream and downstream of each rotor. Cross sectional flow patterns were investigated through the acquired data by the $45^{\circ}$ inclined hot-wire. Flow characteristics such as tip vortex, secondary flow and tip leakage flow were confirmed through axial, radial and tangential velocity vector plot. Swirl velocity, which was generated by the front rotor, was recovered in the form of static pressure rise by the rear rotor except for hub and tip regions.

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Computational Flow Analysis of a Cross-Flow Fan by LES (LES에 의한 관류홴의 전산유동해석)

  • Kim, J.K.;Oh, S.H.
    • Journal of Power System Engineering
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    • v.14 no.6
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    • pp.20-28
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    • 2010
  • The computational flow analysis using LES technique was carried out to investigate the flow characteristics of a RAC chassis consisting of a rear-guider, a stabilizer and a cross-flow fan. The commercial SC/Tetra software was used in this analysis. In view of the results so far achieved, the distribution trends of static pressure and velocity vector of central region except the edges of a CFFan are similar regardless of the number of revolution, and an eccentric vortex exists around the bottom blade of a CFFan. Also, a reverse flow is found in the region between stabilizer and CFFan. Moreover, near the edges of a CFFan, an eccentric vortex is separated to two vortexes. Also these vortexes increase the velocity near a rear-guider, and guide the flow near a rear-guider into stabilizer inlet. Therefore, the reverse flow region is formed in the bottom of a CFFan.

Experimental Study on the Design Parameter Effects on the Flow-rate and the Noise level in a Cross-flow Fan (실험에 의한 직교류홴의 유량 및 소음 분석)

  • Ahn, Cheol-O;Rew, Ho-Seon
    • The KSFM Journal of Fluid Machinery
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    • v.1 no.1 s.1
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    • pp.41-48
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    • 1998
  • This study was carried out to investigate the effect of design parameters on the volume flow-rate and the noise level and to finally find the optimal design variables. Eighteen cross-flow fans were designed by the method of orthogonal array, and the flow-rate and the noise level were measured. These data were analyzed by the neural network system. The effects of eight design variables(scroll exit angle, scroll arc length et al.) on the fan performance and the noise level were valuated and discussed. This experiment shows that the design solutions suggested by neural network system may increase its volume flow-rate and reduce noise simultaneously.

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