• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.101-104
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• 2010

Recently, needs for UAVs and small aircraft and small turbo jet or turbo fan engines for these air-crafts are increasing. Size and weight are the two main restrictions in small air-crafts such as UAV or VLJ propulsion system applications. Therefore, high power density is required in small size and designers come up with unconventional solutions in the design of small aero gas turbine engines. One of the solutions is the usage of highly loaded axial compressors. This paper introduces an aerodynamic design method of a highly loaded axial compressor and its review process. Numerical simulation has been carried out to assess the aerodynamic performance of the compressor.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.6
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• pp.1913-1920
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• 1996

The purpose of this study was to reduce the airborne noise emitted from the package air-conditioner(PAC) therefore, the optimim design melthods of the fans and the flow-paths were investigated experimentally through the anlaysis of the nose problems caused by the conventional PAC system, and the fan performance tests and the systme resistance measurements of the parts which belong to the flow-paths of the PACwere used to study these noise problems. As a results, through the optimized flow-paths of the new PAC system with the lowset system resistance, and by adjusting and matching the operating point of each fan to each PAC system, the airborne noise reductions from the new indoor PAC and the outdoor one were achieved upto 5.5 dBA and 6.6 dBA respectively in overall noise level as compared with the conventional PAC system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.547-552
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• 2000

This paper presents a developed squirrel cage induction motor for axial flow In. Nearly all of the induction motors for fan consists of two parts, rotor and stator, and the position of rotor is located inside of stator. This construction restricts the air flow rate, otherwise requires bending duct. But developed squirrel cage induction motor for axial flow fan exchanged the position each other. So, we can reduce the weight and size about 30%, and there are no bending duct to locate the fan motor.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.3
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• pp.206-213
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• 2002

In this paper, the flow characteristics of an axial fan spraying isothermal compact jet in a confined space were investigated by the experimental methods, the numerical method, and the free jet theory According to the results, the numerical result and the experimental result are agreed well qualitatively and different quantitatively within $\pm1.0%$ for the centerline velocity, the entrainment ratio, and the maximum throw. However, the free jet theory can reasonably predict the centerline velocity except the entrainment ratio and the maximum throw. In other words, the entrainment ratio and the maximum throw by 1.he free jet theory are hard to estimate the characteristics of jet because of restriction of c confined space.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1999.03a
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• pp.55-58
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• 1999

현재 정부는 사회간접자본 확충을 통한 물류비용의 절감이라는 궁극적 목표를 위하여 도로터널의 확충 노력을 적극 경주하고 있으며 터널의 규모 또한 급격히 장대화 하고 있다. 또한 환경 및 안전 측면에서의 규제 강화로 인하여 터널환기 시스템이 점점 복잡해져 가고 있는 추세이다. 환기관련 주요 설비는 제트팬, 축류팬, 집진기, 수갱 등으로 대형화 및 자동화에 따라 운영비용 역시 급격히 증가하고 있으며 운영비용 중의 대부분은 현재 일반전기로 분류되어 있는 환기설비에 소요되는 전력비로, 장대터널의 경우 km 당 1 MW를 훨씬 초과하는 경우도 많아 SOC(사회간접자본)사업으로 추진되는 도로터널의 건설 및 운영상의 문제점으로 지적되고 있다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.196-201
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• 2003

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, experimental study on the fan and system was carried out and brought a successful result of performance and noise from a designed fan. And through the modification of the fan system, the fan produced more flow rate and became less noisy.

• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.9
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• pp.751-761
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• 2003

We performed the numerical analysis on the airflow characteristics in the two type of cleanroom systems, which are the axial fan type (AFT) and the fan filter unit (FFU). A computational fluid dynamic model was applied to investigate and compare the nonuniformity, the deflection angle and the air ventilation effectiveness of the two designs of cleanrooms when dampers are adjusted and not adjusted. And the flow-resistance models of the various components were used in this simulation. We know that the airflow characteristics of the cleanrooms are largely affected by damper adjusting And we also find out that the FFU system is superior to the AFT system through the comparison of the cleanroom performance indices.

• The KSFM Journal of Fluid Machinery
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• v.12 no.2
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• pp.24-30
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• 2009

Flow and noise analyses are conducted for examining a new design concept of impinging jet electronics cooling, and the analysis results are compared with conventional electronics cooling techniques. For the application of impinging jet electronics cooling method, the present study considers the air duct where air is supplied by axial fan and air flow from the duct is impinged vertically onto the electronic component heat source. Applying CFD simulation technique and fan noise model to the present cooling scheme, the cooling performance of the impinging jet as well as the operation condition and the noise characteristics of fan are investigated for various impinging jet nozzle conditions and fan models. Furthermore, the impinging jet electronics cooling analysis results are compared with the conventional parallel-flow cooling scheme to give the design concept and criteria of impinging jet cooling method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.3
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• pp.225-230
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• 2006

The overall performance and local flow fields of the fan, heat sink, and fan-sink were experimentally and numerically studied to investigate the flow characteristics of a fan-sink. The flow resistance of the heat sink was measured by small fan tester based on AMCA standards and compared with the CFD results to select available cooling fan for the fan-sink. The nonuniform velocity profile behind the fan outlet was shown by the flow visualization. The effects of nonuniform velocities on the performance of heat sink were discussed. To validate the commercial CFD code CFX-5.6, the predicted performance curve was compared with that of fan testing. The local flow fields of the fan-sink were analyzed by CFD results. MFR (multiple frame of reference) was used as a computational model combining rotating fan and stationary heat sink. Through the CFD results of the fan-sink, the flow patterns behind the fan outlet influenced the flow resistance and overall performance of the heat sink.