• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.3
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• pp.57-68
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• 2012

In this study, designs of the high efficiency composite propeller blade for a high speed turboprop aircraft, which will be used for a next generation regional commercial aircraft in Korea, are performed. Both the vortex theory and the blade element theory are used for preliminary aerodynamic design and performance analysis of the propeller. Then the aerodynamic design result is confirmed through performance analysis using a commercial CFD code, ANSYS. The carbon/epoxy composite materials is used, and the skin-spar-foam sandwich type structure is adopted for improvement of lightness and structural stability. Finally, it is investigated that the proposed propeller blade has high efficiency and structural safety through both aerodynamic and structural analysis and experimental test of a prototype propeller blade.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.224-231
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• 2009

In this study, an aerodynamic performance analysis code has been developed as a part of rotorcraft comprehensive program. Airloads on rotor blades are calculated based on the blade element theory with look-up tables of aerodynamic coefficients of 2-D airfoils. In order to calculate rotor induced inflow, various inflow prediction methods such as linear inflow, dynamic inflow, prescribed wake and free wake model are integrated into the present module. The aerodynamic characteristics of each method are compared and validated against available experimental data such as Elliot's inflow distribution and sectional normal force coefficients of AH-1G.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.253-258
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• 2012

In this study, designs of the high efficiency composite propeller blade for a high speed turboprop aircraft, which will be used for a next generation regional commercial aircraft in Korea, are performed. Both the vortex theory and the blade element theory are used for preliminary aerodynamic design and performance analysis of the propeller. Then the aerodynamic design result is confirmed through performance analysis using a commercial CFD code, ANSYS. The carbon/epoxy composite materials is used, and the skin-spar-foam sandwich type structure is adopted for improvement of lightness and structural stability. Finally, it is investigated that the proposed propeller blade has high efficiency and structural safety through both aerodynamic and structural analysis and experimental test of a prototype propeller blade.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.3
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• pp.173-184
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• 2013

A multi-level design optimization framework for aerodynamic design of rotary wing such as propeller and helicopter rotor blades is presented in this study. Strategy of the proposed framework is to enhance aerodynamic performance by sequentially applying the planform and sectional design optimization. In the first level of a planform design, we used a genetic algorithm and blade element momentum theory (BEMT) based on two-dimensional aerodynamic database to find optimal planform variables. After an initial planform design, local flow conditions of blade sections are analyzed using high-fidelity CFD methods. During the next level, a sectional design optimization is conducted using two dimensional Navier-Stokes analysis and a gradient based optimization algorithm. When optimal airfoil shape is determined at the several spanwise locations, a planform design is performed again. Through this iterative design process, not only an optimal flow condition but also an optimal shape of an EAV propeller blade is obtained. To validate the optimized propeller-blade design, it is tested in wind-tunnel facility with different flow conditions. An efficiency, which is slightly less than the expected improvement of 7% predicted by our proposed design framework but is still satisfactory to enhance the aerodynamic performance of EAV system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.875-883
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• 2007

The objective of this research was to develop a coaxial rotor MAV which is suitable for a indoor reconnaissance mission. Preliminary design parameters were determined, based on the dimensions of other reference MAVs. The designed rotor performance was estimated by Blade Element Momentum Theory, and the analyses were compared against the measurements. Stability and vibration issues of the prototype were circumvented by making parts of vehicle with NC machine, as well as equipped with teetering rotor and stabilizer. The designed coaxial rotor MAV showed successfully flight equipped with video camera. However, it was founded that further research activities should be focused on efficient rotor design to obtain better performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.648-651
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• 2010

Propeller shall have high efficiency and improved aerodynamic characteristics to get the thrust to fly at high speed for the FAR25 turboprop aircraft. That is way Clark-Y airfoil which is used to conventional turboprop aircraft propeller is selected as a blade airfoil. Javaprop program based on the Adkins method is used for aerodynamic design and analysis of propeller, Adkins method is based on the vortex-blade element theory which design the propeller to satisfy the condition for minimum energy loss. Slipstream displacement don't change and consider a rigid body. High efficiency propeller geometry is generated by varying chord length and pitch angle at design point of FAR25 turboprop aircraft. The propeller design results indicate that could be applied to the FAR25 turboprop aircraft, through analysis of propeller aerodynamic characteristics using the CFD(Computational Fluid Dynamic).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.7
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• pp.479-487
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• 2022

This paper presents the control and guidance algorithm of a KAU-SPUAV(Korea Aerospace University - Solar Powered Unmanned Aerial Vehicle) which is designed and developed in Korea Aerospace University. Aerodynamic coefficients are calculated using the vortex-lattice method and applied to the aircraft's six degrees of freedom equation. In addition, the thrust and torque coefficients of the propeller are calculated using the blade element theory. An altitude controller using thrust was used for longitudinal control of KAU-SPUAV to glide efficiently when it comes across the upwind. Also describes wind estimation technic for considering wind effect during flight. Finally, introduce some guidance laws for endurance, mission and coping with strong headwinds and autonomous landing.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.12
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• pp.1727-1738
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• 2002

세계화, 국제화, 개방화 시대에 살고 있는 우리가 통과의례나 전통 명절과 같은 특별한 행사에 의례복으로 한복을 애용하는 것은 한복이 한국의 문화적 이미지를 강하게 간직하고 있는 한국적 조형물 중의 하나이기 때문이다. 더우기 의례복은 특별한 행사 자체를 위해 착용되었던 만큼 당시대의 내 적 가치를 가장 현저하게 표출하고 있는 복식으로 인정 할 수 있기 때문이다. 본 연구의 목적은 시대 적으로 현대 전통 한복의 기본 형 식을 제공한 조선시대와 그 이후의 복식 중에서 특히 분명한 착용동기와 목적, 복식을 통해 나타내고자 하는 상징성 등을 함축하고 있는 아동용 의례복을 대상으로 복식의 형태, 색채, 문양, 소재 등의 조형 요소를 고찰하는 것이다. 또한 양식적 특성을 살펴보고, 그러한 조형적 특성을 형성시킨 당시대의 사상적 가치를 추론해 보는 것이다. 구체 적인 연구 방법은 먼저 관련된 문헌 고찰을 통한 이론적 배경을 토대로 하여 아동용 의례복의 범주를 설정하고 현재 보전중인 실물과 또는 사진, 풍속화에 나타난 복식 자료들을 수집하였다. 그리고 당시대의 사상적 배경에 대한 고찰을 병행하여 이들에 내재된 문화적 가치를 추출해 보았다. 연구 결과 양식적 특징으로는 남아의 두루마기나 전복 그리고 쓰개류 등에서 기능성을 고려한 변형적 양식이 나타나고 있었다. 색채 역시 음양 보색이나, 오행색을 바탕으로 한 기본색의 구성 이외 에도 소매나 섶에 응용된 색의 배열이나 맞깃 전복의 깃에 나타난 색의 조화는 다양한 색의 조형미를 표현하고 있었다. 특히 색동 등에 나타난 오행색의 배열, 안감과 겉감, 상의와 하의, 외의와 내의에 사용된 색의 조화는 미의식에 관한 문화적 가치를 추론해 볼 수 있다. 더우기 장식 표현에 주로 쓰인 자연물 문양이나 글자 문양은 당시의 지배 사상이 지향하는 덕목 이외에도 전통적으로 내재된 수명과 복록, 부귀와 영화에 대한 내적 가치들을 반영하는 조형적 상징들이라 할 수 있다. 소재는 비교적 계절을 고려하여 사용되고 있었지만 의례적 성격을 지닌 외의나 쓰개류의 경우 계절적 구분을 고려하지 않은 경우도 많이 나타나고 있었다. 장신구의 경우는 많이 사용되는 것은 아니나 역시 상징적 인 가치를 표현하는 실물들을 미적으로 재구성한 사례들이 나타나고 있었다. 이상의 연구를 통해 아동용 전통 의례복은 형태, 색채, 문양, 소재, 장신구 등에서 양식의 다양성과 변형들을 알 수 있었다. 또한 적극적인 내적 가치의 상징들을 복식을 통해 표현하고 있었음을 알 수 있었다. 현대 복식의 디자인에 있어 아동용 의례복에 나타난 창조적인 양식의 변형과 다양성 그리고 복식을 통한 내적 가치의 반영 등이 현대 사회와 조화를 이룬 실질적인 복식 디자인 제시 및 창작에 작은 영감으로 작용하길 바란다.