• 한국군사과학기술학회지
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• 제8권3호
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• pp.33-41
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• 2005

This paper describes the conceptual design of medium size helicopter rotor system. Based on assumed design requirements, trade-off study for rotor configuration has been conducted in terms of rotor tip speed, disk loading, blade area, solidity, etc for estimated primary mission gross weight. For the main rotor, four-blade and five-blade rotors are studied with the conventional tail rotor. The performance analysis for baseline configuration is conducted using a helicopter performance analysis program. The analysis shows design results satisfy the design requirements.

• International Journal of Aeronautical and Space Sciences
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• 제6권1호
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• pp.89-96
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• 2005

Ducted fans have advantages in noise as well as operational safety aspects compared to conventional tail rotors and are used as an anti-torque system for various classes of helicopters. The final goal of this study is to develop a ducted fan anti-torque system which can replace conventional tail rotors of existing helicopters to achieve safety enhancement and low noise level. In this paper, a conceptual design process and the results are described. Initially, the design requirement and the design parameter characteristics are analysed, and then initial sizing and configuration design are performed. There are several configuration changes due to specific technical reasons in each case. Finally, the required power and the pitch link load are predicted as an initial estimation. The conceptual design technique for the ducted fan in this study can be easily applied to the design of other ducted fans such as the lift fan for unmanned aerial vehicle.

• 한국항공운항학회지
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• 제28권1호
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• pp.59-65
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• 2020

This paper presents comparative results of configuration modeling and aerodynamic analysis to single-engine airplanes such as C-172, SR-20, and DA40NG. The software OpenVSP was used as an airplane configuration modeling tool. OpenVSP can provide the fastest method to get three-dimensional aircraft configuration from given basic data and drawings of aircraft. Parametric design input in OpenVSP, from given aircraft geometric parameters, was applied to small airplanes mentioned. New aircraft models in this study were reversely designed to coincide with the publicly obtained dimensions of the original aircraft. The basic aerodynamic analysis of newly designed modeling aircraft was performed by the vortex lattice method. Results are shown that the similarity of aerodynamic data obtained except for the lack of DA40NG. In conclusion, the modeling process applied to this work is valuable to obtain conceptual design insight in the reverse design from the small airplanes currently in use for flight training.

• 한국항공우주학회지
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• 제42권6호
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• pp.478-487
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• 2014

개념설계는 복합시스템인 무인기의 성공적인 개발을 위해 가장 중요한 단계로써 간단한 성능해석과 형상설계가 수행된다. 개념설계 단계에서의 성능해석은 복잡한 해석도구를 사용하기 보다는 주로 경험식이나 통계적 데이터를 이용한 추세방정식을 사용한다. 무인기의 형상은 매우 다양하여 개념설계 단계에서 이러한 모든 항공기 형상을 고려하기에는 어려움이 있다. 본 연구에서는 무인기 개념설계를 위해 주요 성능변수에 대한 추세방정식을 도출하였고, 자주 사용되는 형상 선정을 위해 최대이륙중량 50-1,500kg 급의 중소형 무인기에 대한 데이터베이스를 구축하였다. 또한 주요 성능변수들에 대한 파라미터 분석을 수행하였으며, 이들 성능변수에 대한 상관도 분석결과에 따라 높은 상관도를 보이는 최대이륙중량과 날개폭을 기준으로 각 성능요소별 회귀분석을 수행하여 추세방정식을 도출하였다.

• 한국CDE학회논문집
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• 제5권4호
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• pp.380-392
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• 2000

This paper proposes a qualitative reasoning approach for the spatial configuration of mechanisms that could be applied in the early phase of the conceptual design. The spatial configuration problem addressed in this paper involves the relative direction and position between the input and output motion, and the orientation of the constituent primitive mechanisms of a mechanism. The knowledge of spatial configuration of a primitive mechanism is represented in a matrix form called spatial configuration matrix. This matrix provides a compact and convenient representation scheme for the spatial knowledge, and facilitates the manipulation of the relevant spatial knowledge. Using this spatial knowledge of the constituent primitive mechanisms, the overall configuration of a mechanism is described and identified by a spatial configuration state matrix. This matrix is obtained by using a qualitative reasoning method based on sign algebra and is used to represent the qualitative behavior of the mechanism. The matrix-based representation scheme allows handling the involved spatial knowledge simultaneously and the proposed reasoning method enables the designer to predict the spatial behavior of a mechanism without knowing specific dimension of the components of the mechanism.

• 한국항공우주학회지
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• 제47권3호
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• pp.228-239
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• 2019

단거리 탄도 미사일의 개념 형상을 설계하기 위하여, 부피, 공력, 추진, 구조, 안정성, 비행 궤적 등의 다양한 관점을 고려하는 최적화 문제를 정립하였다. 이를 위하여 기존의 미사일 사례를 분석하여, 설계 조건과 성능지수를 도출하였다. 각 서브 시스템의 모델을 통합하여, 전체 시스템의 성능을 분석하였다. 설계 예시를 통하여, 여러 설계변수가 최종 성능에 미치는 관계성을 분석하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1595-1600
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• 2007

It is necessary a simple helicopter design and performance analysis program for a stage of helicopter conceptual design. To meet that needs, we have developed a program which is simply used to estimate helicopter configuration and performance. The program developed by this study is composed of Requirement, Mission profile Analysis, Size, Aerodynamic, Trim, Propulsion, Weight, and Performance modules, and each modules carry out operations for a given flight condition. In this study, we validate this analysis program in 9,500 1bs and 22,000 1bs helicopters and estimate design configuration and performance of 16,000 1b helicopter. And We can use this program to optimization process for Helicopter MDO framework.

• 한국군사과학기술학회지
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• 제17권2호
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• pp.189-196
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• 2014

Automated design program using commercial process integration and optimization program was developed for conceptual design of fighter-class aircraft. Wind tunnel test data and performance analysis results were compared for the verification of analysis tool of this program, and the usefulness of the tool was found. After integration with radar cross section analysis tool, the correlation with configuration design variables of wing, tail and performance parameters was identified by design of experiment, and the optimized configuration for weight and RCS was derived from optimization of empty weight and average frontal RCS value. After parameter definition of fuselage, the program can be implemented for full aircraft configuration.

• 한국수소및신에너지학회논문집
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• 제20권2호
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• pp.168-178
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• 2009

To check feasibility of SEWGS(Sorption Enhanced Water Gas Shift) system, conceptual design and sensitivity analysis of operating variables have been investigated based on a design program of two-interconnected fluidized bed. Based on the conceptual design results, the optimum configuration for SEWGS was considered. Among three configurations, bubbling beds system was selected as the best configuration. Process design results indicate that the SEWGS system is compact and feasible. Based on the selected operating conditions, the effects of variables such as pressure, $CO_2$ capture capacity, solid inventory, CO conversion and $CO_2$ capture efficiency have been investigated as well.

• 한국국방경영분석학회지
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• 제25권1호
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• pp.87-106
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• 1999

There are many technical datum in related with design, test & evaluation and logistic support which will be exchanged between geographically isolated units and heterogeneous hardwares & softwares in developing and operating the weapon systems. The paper proposes the conceptual database schema to establish configuration management information systems in which these datum can be automatically interchanged, tracked, audited and status-accounted without errors under the various environments. The paper investigates how to identify and classify the data in accordance with document identification, task analysis, system development, logistic support, system test & evaluation and data management. Furthermore, the investigation includes drawing the subject areas and modeling the conceptual database schema to explain the relationships between these datum. Thus, the paper results in the conceptual framework and data models of configuration management information systems, while additional customization efforts be required in applying the models to a specific weapon systems R&D.