• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.203-206
• /
• 1996

The purpose of this paper is to find how to determine the parameters of the basic control system design such as hinge moment coefficients and to display the controllability of the ChangCong-91. Since the estimation from the flight test of real aircraft is the most reliable, we performed the flight test of ChangGong-91 to get the various parameters such as velocity, height, control force, control surface deflection, 3 axis acceleration, 3 axis angular rate, pitch angle, angle of attack temperature and so on. We recorded the flight test data in VHS tapes and stored them to personal computer using A/D(analog to digital) converter. Flight test was done in various conditions, and the acquired data was processed with parameter identification method such as least square method. These data will be utilized for the development of Autopilot System design and Control Loading System design.

• 한국전산유체공학회:학술대회논문집
• /
• 2010.05a
• /
• pp.1-1
• /
• 2010

With the power of supercomputers increasing exponentially, there is an insatiable need for more advanced multi-disciplinary aerospace CFD simulations. A particular current interest is the 3D viscous turbulent simulation of the highly nonlinear aspects of aero-icing. The applications of CFD in that field are literally light-years behind aerodynamics, with a significant number of users still mired in correlations, or 2D, inviscid, incompressible, and, yes, Panel Methods simulations! Thus, the disparity of tools between aerodynamics and icing departments within an organization leads to a disconnect that makes ice protection a downstream isolated process that is not an integral part of the aerodynamic behavior of an aerospace system (aircraft, rotorcraft, jet engine, UAV, etc.). While 3D RANS has been recently introduced, it is still considered computationally too demanding for industry when wide parametric studies for certification are required. In addition, not unlike the situation in aerodynamics say 20 years ago, naysayers are at every corner claiming that CFD is not reliable and is of limited use.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.10a
• /
• pp.250-254
• /
• 2011

Main role of landing gear is to absorb the energy which is generated by aircraft lanidng and ground maneuvering. Generally, in order to absorb the impact energy during landing, oleo-pneumatic type shock absorber is used for aircraft landing gear. Oleo-pneumatic type shock absorber has a good energy absorbing efficiency and is light in weight because its structure is relatively simple. For the landing gear development, it is necessary to conduct drop test in order to verify shock absorbing performance. In the drop test, first, gas spring curve verification tests are conducted. Then, limit and reserve energy absorption drop tests are performed based on the STANAG 4671. The drop tests results with performance analysis results are presented.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1998.03a
• /
• pp.78-85
• /
• 1998

The paper introduces major technical specifications of the Line II railway simulators of Pusan City in Korea. Comparing design specifics of the railway simulators with of the light aircraft Flight Training Device(FTD, the paper reveals commonality of implementation technologies applied to both simulators: Overall configurations and design philosophies are basically the same. In both programs VMEbus computing systems with UNIX are adapted as backbones of the simulators. It is found that the railway simulators are less stringent in real-time requirements than the aircraft FTD, and the railway simulators are designed to be more event-driven and object-oriented. The experiences show that models may be diverse depending on the objects but implementation technologies are about the same. Maximizing portability of implementation technologies is a matter of an organizations strategy of adopting standardized processes and modular technologies available and most economic to them.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.6 no.2
• /
• pp.35-44
• /
• 2003

A Decal Panel is developed for the Night Vision Imaging System of XKO-1 aircraft. The Decal Panel is a kind of lighting system kits and is installed on each system switch box in crewstation. The Decal Panel consists of upper panel made of polycarbonate and lower panel which is a printed circuit board. This paper includes the design, manufacture, test and evaluation of Decal Panel in addition to items and conditions of environmental test. Besides it is confirmed the Key for manufacturing a decal panel, is depth of paint, dry time period and frequency, and diffusion material for spreading of light.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.9 no.2 s.25
• /
• pp.34-41
• /
• 2006

This paper describes the general considerations and operational applications of aircraft night vision goggle(NVG). The operators should recognize the NVG characteristics, natural night light sources and interoperability between them. And they have to keep attention to the method to take steps to avoid misperceptions, illusions during flight, and the negative impact on the effectiveness and safety of the mission. The considerations based on the interoperability between NVG and night operation suggest the evaluation items of NVG field test and flight test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.546-549
• /
• 2004

The T-50/A-50 Golden Eagle was developed for a supersonic trainer and light combat aircraft. At the design stage, vibration control plans were established and applied. For cockpit vibration, crew comfort vibration level was defined by the requirement of MIL-A-8892. It is found that the T-50/A-50 meets the requirement of cockpit vibration from the flight test data analysis. This paper contains the results of cockpit vibration analysis using the flight test data and the results of human vibration analysis lot the pilot inside aircraft. The human vibration level of pilot is increased as dynamic pressure is increased and at the specific high dynamic pressure, the ride comfort indicates 'a little uncomfortable'. Overall analysis results show that the vibration level of T-50/A-50 cockpit is tolerable and not critical for pilot's comfort.

• Advances in aircraft and spacecraft science
• /
• v.6 no.2
• /
• pp.87-103
• /
• 2019

Recently, natural fibre composites are widely used in aerospace industries due to their good specific mechanical properties, better acoustic properties, light weight, readily availability, biodegradability, recyclability, etc. In this study, the hemp fibre woven fabrics / polypropylene based honeycomb sandwich structure were proposed for aerospace applications. Firstly, the hemp fibre woven fabrics based honeycomb sandwich structures were manufactured and experimental mechanical tests (compressive and flexural) were performed in the laboratory. Numerical simulation was also performed and analysed to validate the proposed methodology. Different complex shaped aircraft part CAD models were created and numerical analysis was carried out in order to have a better understanding about the complex honeycomb sandwich structures.

• Journal of Aerospace System Engineering
• /
• v.12 no.4
• /
• pp.18-25
• /
• 2018

The head frame structure of a machine tool for aircraft parts, which requires machining precision and machining of difficult-to-cut materials is required to be light-weighted for precision high-speed machining and to minimize possible deformation by cutting force. To achieve high stiffness and for light-weight structure optimization design, a preliminary model was designed based on finite element analysis. The topology optimization design of light-weight, high stiffness, and low vibration frame structure were performed by minimizing compliance. As a result, the frame weight decreased by 17.3%, the maximum deflection was less than 0.007 mm, and the natural frequency increased by 30.6%. The static stiffness was increased in each axis direction and the dynamic stiffness exhibited contrary results according to the axis. Optimized structure with the high stiffness of low vibration in topology optimization design was confirmed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.3
• /
• pp.255-266
• /
• 2009

In this study, a robust aerospace system design process for the aerospace system is developed by considering the uncertainties of user requirements, manufacturing errors, and operational environment variation. User requirements are analyzed and quantified by decision making models and system engineering methods to select alternative concepts which satisfies the various requirements. Robust design and optimization method is applied to derive the robust solution of the selected system. First, a variance of objective function is calculated, and a mean value and a variance of target value are determined by the deterministic design optimization results of the system. A robust optimum design formulation is then needed to derive the robust solution that minimizes the variance of the response and moves the mean values to the target value. It is applied to Very Light Jet (VLJ) aircraft to which much attention is paid recently in civil aerospace market.