• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.330-335
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• 2016

In this study, aerodynamic characteristics of the blades of a helical-type vertical axis wind turbine(VAWT) have been investigated. For this purpose, a 100-W helical-type vertical axis wind turbine was designed using a design formulae, and a 3D computational fluid dynamics analysis was performed considering wind tunnel test conditions. Through the results of the analysis, the aerodynamic power output and flow characteristics of a helical blade were confirmed. In order to validate the aerodynamic power output obtained through the analysis, a wind tunnel test was performed by using a full-scale helical-type vertical axis wind turbine. The 3D analysis technique was validated by comparing its results with those obtained from the wind tunnel test.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.7
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• pp.705-710
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• 2012

In this study, an experiment on an air conditioning test bench was performed to verify the possibility of fuel economy simulation for the SC03 mode, North America fuel economy certification mode with a/c on condition, one of the vehicle fuel economy evaluation modes. The air conditioning test bench used in this study had each chamber simulating the actual vehicle air conditioning system and the controlling temperature, humidity, and air flow velocity to reproduce environmental conditions. Reliable results were obtained about the compressor RPM and inlet air velocity in front of the condenser corresponding to vehicle speed and air velocity in front of the vehicle, respectively, in the simulation of the SC03 mode, previously performed in CWT, in an air conditioning test bench. It was also discovered that there was a distinct difference in the fuel economy depending on the difference in the compressor displacement in the simulation test of the SC03 mode in the air conditioning test bench under various displacement conditions of the compressor.

• Explosives and Blasting
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• v.17 no.2
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• pp.45-51
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• 1999

To find out the characteristics and trend of dust fall in open cut limestone mine in-situ measurement and wind tunnel tests were carried out. In-siti measurement was done by two dust fall samplers at the Halls mine for 60 days. The laboratory test was done in the 100m long temporary wind tunnel installed at the yard of the institute. The most of dust falled within 25m form the dust source and only less than 0.5% defused up to over 100 meters. It was known that the dust fall at 100m away from souces were negligible.

• Journal of Ocean Engineering and Technology
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• v.4 no.2
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• pp.172-172
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• 1990

• The Science & Technology
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• v.32 no.12 s.367
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• pp.30-31
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• 1999

포항공대 첨단유체공학연구센터는 기체나 액체의 흐름을 제어하여 효과적인 에너지 활용을 위한 연구에 총력을 기울이고 있다. 운송체 유동 연구부, 열교환기 연구부, 환경 및 생체유동 연구부로 나누어 효율적인 연구활동을 펴고 있는 이 연구센터는 비행기, 자동차, 건물 등 물체표면의 공기저항을 측정하는 풍동을 비롯해 고성능 수퍼컴퓨터 등 첨단장비를 갖추고 있으며 미국을 비롯한 세계 7개국의 10개 연구기관과 상호 교류를 하고 있다.

• Journal of Bio-Environment Control
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• v.7 no.3
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• pp.181-190
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• 1998

An elastic analysis under wind load was performed for the double layered plastic greenhouse model developed particularly for minimizing damages under typhoons at Cheju Citrus Research institute in Seagipo city. General EVA film was used for the inner covering and the developed special film which would break the wind pressure down was used for the outer covering. The wind tunnel test showed this special film reduced the wind speed up to 86 to 98% under well controlled situation. Based on the elastic analysis performed in the study, the behavior of the greenhouse was changed significantly due to the boundary conditions. Not like other researchers before we applied dead load of the concrete support to the ground pipe and fixed support boundary conditions at the 4 corner pipes. The analysis shows that the greenhouse was lifted and pulled the pipe out of the ground due to the sucking wind pressure. The behavior of the greenhouse was quite similar to that one real greenhouse failure. Therefore, not only we need to find the realistic boundary conditions for the supports, but also need to find how to rest the pipe supports on the ground without economic loss.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.1
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• pp.59-65
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• 2013

In this study, the effects of the compressor for the air conditioning system on the fuel economy were experimentally investigated in an actual automobile. This study aims to analyze the level of contribution of the driving torque of the compressor to the fuel economy. A torque sensor, which is directly set on the clutch of the compressor, is developed to obtain data about the compressor load, which influences the fuel efficiency, and then, the reliability of the torque sensor is verified by comparing the results with those of a torque meter in a bench test. An actual automobile equipped with the compressor and torque sensor is operated in a climate wind tunnel in which appropriate facilities are set up to evaluate the fuel efficiency. The compressor driving torque resulting from the difference in the compressor displacement is found to influence the fuel economy, and the fuel economy is found to be worsened by up to 2~3% with an around 11% increase in the compressor displacement under the same conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.5
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• pp.359-366
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• 2017

In this paper, aerodynamic data of the Gaori kite was constructed through the wind tunnel experiment taking into consideration all the angles of attack formed during the flight of the Gaori kite. From this aerodynamic data, we made a morphing analysis of the relative length of the front bridle to the rear bridle required to achieve equilibrium flight as the angle of attack of the Gaori kite or the azimuth angle change. As a result, it was found that the relative length of the front bridle to the rear bridle depends entirely on the chord length of the kite, the relative wind speed and changes morphed according to the angle of attack. Using this information data, one can adjust the relative length of the bridle line to suit the kite attitudes and flight environments handling the kites that maintain optimal flight performance.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.289-295
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• 2006

A computational fluid dynamics (CFD) numerical model has been developed to effectively study the ventilation efficiency of multi-span greenhouses with internal crops. As the first step of the study, the internal plants of the CFD model had to be designed as a porous media because of the complexity of its physical shapes. In this paper, the results of the wind tunnel tests were introduced to find the aerodynamic resistance of the plant canopy. The Seogun tomato was used for this study which made significant effects on thermal and mass exchanges with the adjacent air as well as internal airflow resistance. With the main factors of wind speed, static pressure, and density of plant canopy, the aerodynamic resistance factor was statically found. It was finally found to be 0.26 which will be used later as an input data of the CFD model. Moreover, the experimental procedure of how to find the aerodynamic resistance of various plants using, wind tunnel was established through this study.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.83-89
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• 2008

A wind tunnel test was conducted at Protected Horticulture Experiment Station of National Horticultural Research Institute in Busan to find the aerodynamic resistance and quadratic resistance coefficient of chrysanthemum in greenhouse. The internal plants of the CFD model has been designed as a porous media because of the complexity of its physical shapes. Then the aerodynamic resistance value should be input for analyzing CFD model that crop is considered while the value varies by crops. In this study, the aerodynamic resistance value of chrysanthemum canopy was preliminarily found through wind tunnel test. The static pressure at windward increased as wind velocity and planting density increased. The static pressure at leeward decreased as wind velocity increased but was not significantly affected by planting density. The difference of static pressure between windward and leeward increased as wind velocity and planting density increased. The aerodynamic resistance value of chrysanthemum canopy was found to be 0.22 which will be used later as the input data of Fluent CFD model. When the planting distances were $9{\times}9\;cm$, $11{\times}11\;cm$, and $13{\times}13\;cm$, the quadratic resistance coefficients of porous media were found to be 2.22, 1.81, and 1.07, respectively. These values will be used later as the input data of CFX CFD model.