• International Journal of Aeronautical and Space Sciences
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• 제15권3호
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• pp.309-319
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• 2014

This paper mainly focuses on the conceptual design and stealth performance of the three-surface military aircraft. A three-dimensional (3-D) digital mock-up of the three-surface strike fighter with stealth feature was designed and the schemes of carrying missiles were analyzed in CATIA. Based on physical optics principle and the Method of Equivalent Currents (MEC), a numerical simulation of the RCS feature of the aircraft was carried out with RCSPlus which is a software designed by Beihang University. The paper contributes to the RCS feature analysis of the whole plane and different parts on X-band, S-band and UHF-band and a comparison of RCS feature to Su-37 and T-50 military aircraft is drawn. On X-band, the pitch angle of the incident wave was $0^{\circ}$, and the result shows: (1) Compared with Su-37 aircraft, the forward scattering RCS of the three-surface strike aircraft was reduced to 14.9%, the side scattering RCS to 9.6% and the back scattering RCS to 40.2%. (2) Compared with T-50 aircraft, the forward scattering RCS was reduced to 38.61%, and the side scattering RCS to 67.26%. This paper should be useful for researchers in conceptual design and stealth technology of the military aircraft.

• International Journal of Aeronautical and Space Sciences
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• 제14권3호
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• pp.222-228
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• 2013

A jetfighter shape modeling method based on design features is researched, to improve the efficiency of shape modeling in the stage of conceptual aircraft design. The aircraft's general design features and shape parameters, including geometric and position parameters, are described. The coordinate systems of the entire aircraft and its components are defined. As a sample of local shape, a method of inlet intake modeling is introduced. The whole process of the modeling method is proposed. Three examples of different jetfighters are listed, to describe the achievement of basic layout, which includes four main elements. The Fusion of Components can be achieved by regulating the details of the sections of the fuselage. Sample Cases of typical layouts are shown to verify the effectiveness of the proposed method, which provides the basis for further analysis and optimization.

• 한국항공운항학회지
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• 제19권4호
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• pp.67-73
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• 2011

For loads analysis of airplane, applicable regulation should be determined. Then, loads conditions are prepared from the regulation. Modeling for aerodynamic, mass, and structure are performed. Panel method is usually adopted for aircraft loads analysis to obtain air loads. The ARGON which is a multidisciplinary fixed wing aircraft design software co-developed by the KARI and TsAGI are used for loads analysis. The ARGON can be utilized for flutter and stress analysis as well as for flight and ground loads analysis. In this paper, flight loads analysis for wing structural design of the regional aircraft at the conceptual design phase are performed with the ARGON. FAR 25 is used for the regulation for the load analysis. Shear force, bending moment and torsion diagrams for the wing and shear force and hinge moment for the aileron are presented.

• 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.

• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.101-108
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• 2016

The RCS characteristics of stealth modified three-surface aircraft are analyzed in this paper. Prototype A is built with CATIA software and the three-dimensional digital models of modified stealth three-surface B and C are also designed based on carrier-based aircraft Su-33; the numerical simulation of RCS characteristics of three-surface aircraft is conducted with RCSAnsys software based on physical optics method and the method of equivalent currents; The following results are obtained by comparative analysis and mathematical statistics: (1) by the use of physical optics method and equivalent electromagnetic current method, the scattering intensity for each part of the model and RCS characteristic of the aircraft can be analyzed efficiently and accurately; (2) compared with model A, the mean RCS value of model B is reduced to 14.1% in forward direction and 48.1% in lateral direction; (3) compared with model A, the mean RCS value of model C decreases to 11.4% in forward direction and 21.6% in lateral direction. The results are expected to provide theoretical basis and technical support to the conceptual design of aircraft and stealth technology research.

• 한국항공운항학회지
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• 제17권4호
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• pp.48-54
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• 2009

We implemented the Aural Cueing System(ACS) system of the reconfigurable tactical trainer(RTT) for th rotor aircraft. RTT provides a collective training system to meet aviation training requirements and supports organizational training for aviations units in combined arms collective training and mission rehearsal. ACS handles the volume, pitch and repetition of the digitally stored sounds based on commands it receives from an UDP/IP. In this paper, we explained and implemented the conceptual and detail design the ACS system for the rotor aircraft such as AH-1H(Iroquios), UH-60(Blackhwak), AH-1(Cobra) etc. The conceptual design composed of the sound cueing data analysis, sound modelling which is inner, outer, weapon and warn environment of rotor aircraft, sound synthesis and replay.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.70-82
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• 1999

During the aircraft conceptual design stage, rapid aerodynamic analyses over various configurations are required. Hence, empirical and analytical methods play important roles in predicting the aero-dynamic characteristics. In this study, total drag estimation method based on empirical and analytical approaches is developed. By comparing with the results of the wind tunnel experiment and existing prediction methods, it is demonstrated that the developed method is accurate and useful in predicting total drag for the whole Mach number range.

• 한국항행학회논문지
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• 제22권2호
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• pp.84-89
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• 2018

국내 기술의 발달로 인하여 다양한 항공기 발사 무장이 개발되고 있으며, 항공기-무장통합 인증에 대한 중요성 역시 높아지고 있다. 항공기-무장 통합 인증은 표준감항인증기준 (Standard ACC; standard airworthiness certification criteria)에서 제시하는 무장/장착물 통합 기준에 대한 적합성을 검증하여 안전 비행에 문제가 없다는 것을 증명하는 것으로, 무장 개발 후 항공기 통합 과정에서 요구되는 다양한 기준을 만족시켜야 함을 의미한다. 따라서 항공기의 요구사항을 무장 개발 과정에서 반영하여야 적합성 검증 단계에서 설계 변경 소요를 줄일 수 있다. 본 논문에서는 표준감항인증기준과 항공기-무장적합성 기준문서인 MIL-HDBK-1763, 그리고 순항유도무기 개발 프로세스간의 상관성을 분석하였다. 분석 결과 설계 초기 단계부터 공력 및 구조설계 분야에서 항공기 요구사항을 반영하여 개발을 진행하는 경우 항공기-무장 통합 인증 단계에서의 설계 변경 발생을 줄일 수 있다고 판단하였다.

• International Journal of Aeronautical and Space Sciences
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• 제15권4호
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• pp.366-373
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• 2014

A conceptual design of a three-surface strike fighter was studied and stealth performance was taken into account to enhance survivability and battle effectiveness. CATIA was used to design the aircraft's three-dimensional prototype model and the weapon carriage arrangement was also studied. The aircraft's RCS characteristics and distributions under X, S, C, and L bands were simulated using the RCSPlus software, which is based on the PO method. Pressure and velocity distributions of the flow field were also simulated using CFD. A turbulence model was based on standard $k-{\varepsilon}$ function and N-S functions were used during the CFD computation. Lift coefficients, drag coefficients, and lift-to-drag ratio were obtained by aerodynamic simulation. The results showed that: (1) the average value of head-on RCS between ${\pm}30^{\circ}$ is below -3.197 dBsm, and (2) the lift coefficient is 0.34674, the drag coefficient is 0.04275, and the lift-to-drag ratio is 8.11087 when the attack angle is $2.5^{\circ}$.

• International Journal of Aeronautical and Space Sciences
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• 제15권4호
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• pp.383-395
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• 2014

According to the requirement of wing weight estimation and frequent adjustments during aircraft conceptual design, a wing weight estimation method considering the constraints of structural strength and stiffness is proposed to help designers make wing weight estimations rapidly and accurately. This method implements weight predictions on the basis of structure weight optimization with stiffness constraints and strength constraints, which include achievement of wing shape parametric modeling, rapid structure layout, finite element (FE) model automated generation, load calculation, structure analysis, weight optimization, and weight computed based on modeling. A software tool is developed with this wing weight estimation method. This software can realize the whole process of wing weight estimation with the method and the workload of wing weight estimation is reduced because much of the work can be completed by the software. Finally, an example is given to illustrate that this weight estimation method is effective.