• The KSFM Journal of Fluid Machinery
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• v.15 no.5
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• pp.37-41
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• 2012

High-efficiency and low-noise axial flow fan is developed by combining the FanDAS, a computerized axial fan design/performance analysis system, and CFD software(CFX). Based on fan design requirements, FanDAS conducts 3-D blade geometry design, quasi-3D flow/ performance analyses and noise evaluation by using through-flow analysis method and noise models for discrete frequency and broadband noise sources. Through the parametric studies of fan design variables using FandDAS, preliminary and baseline design is achieved for high efficiency and low noise fan, and then can be coupled with a CFD technique such as the CFX code for constructing final and optimized fan design. The FanDAS-CFX coupled system and its design procedure are applied to actual fan development practice. The FanDAS provides an optimized 3-D fan blade geometry, and its predictions on the performance and the noise level of designed fan are well agreed with actual test results.

• Korean Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.201-209
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• 1998

To develop timely an optimal fan, a design system and a new manufacturing process used step by step have to be integrated. A small sized optimal fan for refrigerators, that was the goal on this project, was developed by the following principal processes. All processes are technologically linked in many directions: The existing fan was measured through reverse engineering. The measured data was used for the basic source of 3D design. The performance tests were carried and used as the data for the evaluation of the existing fan. Flow analysis by FANS-3D/sup [1]/ was performed at the given information (pressure drop and flow rate) to find out the configuration of optimal fan design. The flow patterns were investigated to measure the performance of fan through numerical experiment. The grid point data obtained by the above analysis turned into 3D high efficiency fan model by using CATIA. The product was manufactured by RP process (SLS, SLA) and tested the characteristic curves of the developed fan to compare with the existing fan. The modification of fan design were all examined to see any change in performance and checked to find any deficiency in assembling the fan into a duct. After the plastics flow analysis of the injection molding cycle to ensure acceptable quality fan, an optimal mold was processed by using tool-path for the newly designed fan.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.529-535
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• 2001

A centrifugal fan design code was developed and packaged together with iDesignFan／sup TM／ as new models. This code generate centrifugal forward curved and backward curved bladed impeller optimally. It also predicts the aerodynamic performance and the overall sound pressure level of the rotating fan by assuming steady blade loading. The overall sound pressure level is used as an input parameter from the third loop of the designing process to acquire the most silent fan for the given aerodynamic performance parameters. With this kind of inverse design concept used in the code, the period of designing a fan is significantly shortened. A centrifugal fan design code, developed in this study and included in iDesignFan／sup TM／, predicts the aerodynamic performance such as design flow rate and static pressure. The aerodynamic performance in the design and off-design conditions is calculated by using the mean line analysis. For the steady loading calculation, the lift force distribution in a blade is used.

• The KSFM Journal of Fluid Machinery
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• v.13 no.1
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• pp.42-51
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• 2010

Many different types of fan have been applying to various industrial fields. Fan design methods are much different depending on the types of fan, operating conditions, and connecting parts at the inlet or exit of the fan etc. In this study, design methods for an axial-type suction fan are studied. This fan discharges the air in the relative static pressure of -285Pa to the atmosphere with the flow rate of $960m^3/min$. For three-dimensional blade design, three different design methods were applied, such as the free vortex method, the exponential method, and the cascade method. In the cascade method, the blade loading along the radial direction was obtained from the lift coefficient which was necessary to obtain the pressure rise on a fan rotor. This method is different from the free vortex and the exponential method which control the strength of the vortex. The fan performance prediction was conducted using the CFD with three different inlet ducts. The best fan performance was obtained when the fan was designed by using the cascade method. The designed fan using the exponential method showed better performance compared to a fan designed using the free vortex method. However, the fan performance was changed depending on the installed inlet ducts. So, an efficient fan can be designed with the adjustment of design variables on the basis of the flow structures within the fan as well as the fan design procedure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.967-972
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• 2001

An axial fan design code, called iDesignFan$^{TM}$, was developed. In this code, three major loss models were used to predicted the aerodynamic performance of a fan. The overall sound pressure level, predicted from steady blade loading, is also used as an input parameter from the third loop of the designing process to acquire most silent fan for the given aerodynamic performance parameters. With this kind of inverse design concept used in this code, the period of designing a fan, which has given aerodynamic performance with minimal acoustic noise, is significantly shortened. The experimental results of a prototype fan, designed by this code, showed that aerodynamic and acoustic performance of an axial fan is reasonably well predicted. Thus, one can design/develop an axial fan in a short time by using the code.e.

• Korean Journal of Computational Design and Engineering
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• v.2 no.2
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• pp.85-92
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• 1997

An axial flow fan design system has been made by integrating the self-developed programs and I-DEAS. By using the system, an axial flow fan was designed, manufactured and verified through the wind tunnel experiments in coorperation with a refrigerator appliance division. It has been shown that the optimal design without the ambiguity of the design parameters can be possible by the three-dimensional flow simulations using a self-developed CID code, FANS-3D. (Flow Analysis code using Navier Stokes aguations in Three-Dimensional curvilinear coordinates). By virtue of the fluency of the data flow, an optimally designed fan which satisfies design conditions can be selected in a short time and less cost. The manufacturing processes of a Mock-up and an injection molding die have been automated through the self-made interface programs which connnect from the start to the end. It has been shown that the newly developed fan by this system has a superior performance characteristics to an existing fan.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.11-16
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• 2001

It is not easy to apply a small-sized centrifugal fan to the duct used for the thermal management of home electronic appliances due to complex design parameters of its blades and scroll. The main objective of this study was to develop the systematic process to design an optimal centrifugal fan based on the 3-dimensional configuration of blades obtained from the conceptual design program self-developed with the given design constraints such as the flow rate, the total pressure loss, the size of fan, and the number of rotation. The design process to find an optimal centrifugal fan for refrigerator was technologically linked in many ways. The complex grid generation system of the fan model included scroll was adopted for the numerical simulation. The FVM CFD code, FLUENT, was used to investigate the three dimensional flow pattern at the coordinate system of rotating frame and to check the optimal performance of the fan. By using this design process, a selected centrifugal fan was designed, numerically simulated, manufactured and experimentally tested in the wind tunnel. The performance curve of fan manufactured by NC process was compared with numerically obtained characteristic curve. The developed design method was proved into being excellent because these two curves were well matched.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.37-42
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• 2001

A computerized axial flow fan design system is developed with the capabilities for predicting the aerodynamic performance and the noise characteristics of fan. In the present study, the basic fan blading design is made by combining vortex distribution scheme with camber line design, airfoil selection, blade thickness distribution and stacking of blade elements. With the designed fan blade geometry, the through-flow field and the performance of fan are analyzed by using the streamline curvature computing scheme with spanwise total pressure loss and flow deviation models. Fan noise is assumed to be generated due to the pressure fluctuation induced by wake vortices of fan blades and to radiate as dipole distribution. The vortex-induced fluctuating pressure on blade surface is calculated by combining thin airfoil theory and the predicted flow field data. The predicted performances, sound pressure level and noise directivity patterns of fan by the present method are favorably compared with the test data of actual fans. Furthermore, the present method is shown to be very useful in designing the blade geometry of new fan and optimizing design variables of the fan to achieve higher efficiency and lower noise level.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.25-31
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• 2011

The performance of fan for engine room of ship is absolutely important when it take into consideration work efficiency, work condition, and the performance of various equipments. Fan performance test should be carried out during sea trial to satisfy owner's requirement as above mentioned. We have considered various values to affect fan test result. In here, various values are to be silencer, fan inlet shape, and arrangement of fan room. In general, the shapes of fan inlet is overall circular type because of the shapes of axial fan. So, all vessels built at SHI have been applied fan inlet of circular type. And now, in order to reduce sound of noise from supply fan, big silencer often has been installed at high value vessels. In this case, the capacity of supplied air can be insufficient due to silencer which is an obstructer about air flow. In this paper, we have studied the performance of fan through comparison between a circular shape and a square shape of fan inlet. We also compare with CFD results and experimental results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.275-281
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• 2001

While basic input parameters for the performance and noise of axial fan are flow rate, pressure rise, rotating speed, and fan diameter, the geometric parameters of blade are sweep angle, solidity, and camber angle. The sweep angle does not affect fan performance much, but on fan noise significantly. Solidity and camber angle are very critical design parameters acting on the fan performance directly. The solidity and camber angle are closely related, therefore they have to be carefully determined for the low-noise and high-performance fan. In This paper, different design points are selceted and also geometric parameters are deliberately changed for the comparison of fan noise. As a result, at the same performance, the input rotational speed affects radiated noise more significantly than others. When solidity and camber angle are increased more than those by iDesignFan／sup TM／ program, more noise is experienced. The blade sweep method and blade numbers at same solidity are observed to results in different levels of performance and noise.