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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society for Aeronautical & Space Sciences
Journal Basic Information
Journal DOI :
The Korean Society for Aeronautical & Space Sciences
Editor in Chief :
Volume & Issues
Volume 28, Issue 7 - Oct 2000
Volume 28, Issue 6 - Sep 2000
Volume 28, Issue 5 - Aug 2000
Volume 28, Issue 4 - Jun 2000
Volume 28, Issue 3 - Apr 2000
Volume 28, Issue 2 - Mar 2000
Volume 28, Issue 1 - Feb 2000
Volume 28, Issue 8 - 00 2000
Selecting the target year
The Wind-tunnel Investigation of the Effect of Vortex Generators on the Multi-Element Airfoil
Cho, Auk-Chan ; Hong, Hyun-Eey ; Jeong, Woon-Gab ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 1~1
Subsonic wind tunnel experiments of multi-element airfoil were conducted to investigate the pressure distribution on the airfoil surface for the effect of vortex generators which were located in different chordwise positions, 25%, 40% of the main airfoil chord and 25% of the flap chord, then compared with the case without vortex generators. the results reveal that vortex generators at angle of attack
and location of
can effectively reduce boundary layer separation on the multi-airfoil surface and alleviation of separation significantly improves performance of the high-lift system.
A Study on the Aerodynamic Characteristics of a Lozenge-Shaped Variable Wing
Lee, Bong-Joon ; Eom, Ick-Sub ; Kim, Hark-Bong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 12~12
The lozenge shaped variable wing is a joined wing which employs tandem wings having positive and negative sweep angle, arranged to form lozenge shapes in plane views. A wind tunnel test was performed to study the effects of the geometry parameters of the joined wing on the aerodynamic characteristics for the lozenge shaped variable wing. The experimental results show that, for the plain joined variable wing, rectangular shaped wing presented good performance in lift to drag ratio characteristics and, for the upper joned variable wing, the lozenge shaped wing had high lift to drag ratio compared to that of other models with no sweep. It is also shown that the lozenge shaped variable wing had no effects on the pitching moment coefficient affecting on the stability margin.
Development of A New Searching Algorithm for an Overlapped Grid System
Park, Jong-Hoon ; Kwon, Jang-Hyuk ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 21~21
A new algorithm for fast searching hole points, fringe points, interpolation elements and interpolation coefficients utilized in overlapping grid systems is presented. A fast searching algorithm is required in overlapped grid system since it can occur to pay much time to search hole points, fringe points and interpolation elements. Present algorithm searches fringe points prior to searching hole points in contrast with other algorithms, so fringe points have a sequence and it is not necessary to search hole points. The sequence of fringe points makes it possible to search donor elements fast since it can use the donor element of the prior frige point for the initial guess of the donor element of the present fringe point. And present algorithm connects the fringe point of current step with the fringe point of previous step in case of relatively moving body problems so that present algorithm for moving body problems is much faster than that of steady problems since it can use the result of the previous step for the initial guess of the current step. Application problems of the present searching algorithm are presented for various 2-D and 3-D overlapped grid systems.
Interaction of Shock Waves Discharged from Multiple Slits
Jung, Hwi-Hwa ; Chang, Se-Myong ; Chang, Keun-Shik ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 31~31
Interaction of shock waves discharged from the multiple slits is studied numerically and experimentally using the KAIST shock tube. Investigation is made on such distinct flow regions as flow entering the slits, flow in the narrow slits, flow in the vortex-shock interaction region, and the relatively uniform flow behind the shock front. Visualization of the shocks and vortices associated with the jets from the single, double, and multiple slits is made using the holographic interferometry and shadowgraphy, the images of which are compared with the numerical results.
Measuring of dynamic elastic modulus of Carbon-epoxy composites at various temperatures.
Choe, Sun-Gwon ; Park, Se-Man ; Lee, Dong-Sik ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 36~36
Use of composite materials has been steadily on the rise in industries requiring light weight and high strength materials, especially in productions of automotive, aircraft, ships and the construction of various structures. This trend naturally leads to comprehensive research activities. To ensure integrity and reliability of those industrial products, it is essential that materials used for the fabrications should be subjected to careful measurements of their properties and to various non-destructive tests for evaluations of suitability of the materials used for the productions. In this investigation an acoustic resonance method is utilized to determine resonance frequencies of transversely isotropic composite materials, providing means to establish values of elastic constants of the composite materials. Also, changes in the elastic constants are continuously monitored under various applied thermal conditions at elevated temperatures.
The Size Optimization of Airframe Primary and Secondary Structures by the Stepwise Refinement of Finite Element Meshes
Kim, Cheol ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 43~43
Efficient procedures for the design optimization of large complex primary and secondary structures which can improve the time of design cycles, the convergence to the optimal design, and design reliability are proposed when the structures are subjected to component loads at the detailed design stage and are successfully applied to the detailed design optimization of engine mount fittings and canopy supporting structures. The optimization studies on these important parts attached to a fuselage are not easily noticed. For this study an aircraft coarse grid FE model and components fine mesh FE models are constructed for preliminary and detailed sizing, respectively and optimization is performed using NASTRAN, in sequence of primary structures sizing by flight and inertia loads, secondary structures sizing and design changes by component loads, and assemblage sizing.
Numerical Optimization of Problems with Interior Point Constraints
Choi, Kee-Young ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 51~51
This paper develops an algorithm for finding optimal solutions of problems with both interior and terminal point constraints and show how to implement it numerically. Both the interior and terminal constraints may be specified either at fixed or at free time marks. The method is applied to two problems: two dimensional guidance of a point mass and control of a two-link manipulatorl. For the first problem, the solution is validated with a dynamic programming method. Both programs resulted in the same optimal solution, but the current method showed superior efficiency. The method is also successfully applied to a two-link manipulator problem, which demonstrated the applicability to a nonlinear problem.
Fuel-efficient Input Shaping Method for Slew Maneuver of Flexible Spacecraft
Jung, Dong-Won ; Kim, Sung-Pil ; Kim, You-Dan ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 59~59
In this paper, improved control method is proposed for slewing and vibration suppression of flexible spacecraft using input shaping method. Constant amplitude fuel-efficient input shaper is designed using frequency domain approach. Actuator bandwidth is considered for realistic design application. The numerical results and experiment results show that the accurate slew maneuver is achieved without residual vibration.
Vibration Measurement of a Cantilever Beam Using GPS Carrier Phase
Suh, Dea-Wan ; Lee, Young-Jea ; Park, Hoon-Cheol ; Yoon, Kwang-Joon ; Jee, Gyu-In ; Park, Chan-Gook ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 68~68
GPS carrier phase is supposed to provide the tool for the most precise 3 dimensional positioning information. The FAST, an OTF technique, has been developed by the GPS System Laboratory of Konkuk University, and has shown several millimeter level accuracy in root-mean-square sense. This OTF's high precision positioning capability provides an adequate tool of low frequency vibration monitoring of large structures. In this paper, the possibility of vibration measurement of a cantilever beam using FAST has been tested, which is supposed to be extended to more practical applications. The results of the experiment have been compared with those by a strain gage and laser sensor.
Flight Range Control of Atmosphere Re-entry Space Vehicle Using the Reference Trajectory Correction
Lee, Dae-Woo ; Cho, Kyeum-Rae ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 77~77
Atmosphere re-entry guidance and control becomes more important due to the construction and maintenance of space-station. It can be divided into three control parts which are longitudinal, lateral, and flight range. Flight range is biased from the initial designed range due to longitudinal/lateral control. The reduction of this bias is called as flight range control. There are papers for shuttle range control with different equation in each phase, but they have complicated equations. This paper proposes the simple flight range control scheme. At first, it involves the prediction of sectional range based on the range from the current point to the final point of re-entry guidance using simple numerical integration, and calculation of the error between predictive remained range and real remained range, and achievement of the flight range control using the correction of the reference drag acceleration obtained from optimal algerian. This flight range control can achieve shortening of time as well as reduction of flight range error.
Instantaneous Impact Point Calculation Algorithm of Sounding Rockets and Its Application to Range Safety System
Ahn, Jae-Myung ; Roh, Woong-Rae ; Park, Jeong-Joo ; Cho, Gwang-Rae ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 86~86
An algorithm to predict IIP (Instantaneous Impact Point) of a sounding rocket is proposed. With known current position and velocity vector in 3-dimensional inertial fame, longitude and latitude impact point in rotating Earth is calculated. Central inverse-square gravity field is assumed and no other approximation is added. Calculation is performed without any iterative process so that real-time prediction of IIP is guaranteed. To operate the algorithm in a range safety system, augmented formulations are achieved with additional coordinate transforms between inertial coordinate system and launch-site coordinate system. Proposed algorithm is verified by 6-DOF simulation of KSR-III sounding rocket.
Optimal Design of the Attitude Controller for a Flexible Launch Vehicle with Engine Inertia Effect
Heo, Jong ; Park, Chang-Su ; Tak, Min-Je ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 94~94
The longitudinal equations of motion for a flexible launch vehicle controlled by thrust vectoring are derived and optimal attitude controller of the vehicle is designed. When the engine inertia effect is included in the equations or motion, additional Tail-Wags-Dog (TWD) zeros are produced in the launch vehicle system. As the TWD zeros related with the high-order structural bending mode affect the stability of the flexible launch vehicle, this effect should be considered in designing the attitude controller. The attitude control system of the flexible launch vehicle composed of the classical type controllers are optimized by the Evolution Strategy (ES), which is a stochastic optimization technique. Optimal attitude controllers are designed for the engine inertia effects and the design results are analyzed.
The Characteristics of NOx emission in the opposed impinging jet flame with the offset
Seo, Jong-Won ; Lee, Chang-Jin ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 104~104
The NOx emission and pressure characteristics were experimentally studied with the variation of orifice diameters and offset scales in the opposed impinging jet flame. With an appropriate offset scale, it was found that the ignition delay was increased and the main combustion duration was decreased since the turbulence could enhance the mixing process and suppress the chemical reactions. Specially, it was observed that the onset of an offset had a great influence on the decrease in the main combustion duration. Therefore, the combustion phase in the Borghi diagram showed the transition toward the distributed reaction that was manifested by the decrease in NOx emission and the slight increase in the maximum pressure. And it was also found that the optimal offset scale for a given pre-chamber volume could contribute to producing the lowest NOx.
Radiation Pattern and Hazardous Zone Analysis of the Uplink Antenna of the KOMPSAT Mission and Control System
Chung, Dae-Won ; Kim, Jong-Woo ; Choi, Hae-Jin ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 110~110
To communicate with the Korea Multi-Purpose SATellite(KOMFSAT) rotated at 685km above the ground, the KOMFSAT Mission and Control System(KMCS) performs communication with the satellite via S-band and radiates electromagnetic wave as transmitter power and antenna characteristics required. Because the electromagnetic wave radiating from the ground to the satellite has high transmitter power and gain, it needs to analyze antenna radiation pattern and establish the hazardous zone considering impact to equipment and human beings nearby. Before establishing the hazardous zone, it is referred to limit of exposure suggested by International Radiation Protection Association/International Commission on Non-ionizing Radiation Protection(IRPA/ICNIRP) as a guideline on limit of exposure. The antenna operation guidelines of the KMCS are suggested to satisfy with the limit of exposure above and the hazardous zone suggested by Electronic Industries Association(EIA) is applied to that of the KMC5. In the present paper also, the characteristics of the near field and far field of the electromagnetic wave radiated from the KMCS is considered and the radiation pattern of the uplink antenna of the KMCS is referred.
Transient temperature analysis of the brake system on basic trainer using finite element method
Choi, Sup ; Park, Chong-Yeong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 116~116
This study investigates the thermal behaviors of the brake system on basic trainer. A finite element analysis of thermal transient temperature is performed using multi-contact 3D model for describing geometrically complex and unsymmetric shape. Numerical results are presented for discussing the thermal behaviors considering braking power, convective heat coefficients, thermal contact conductances, ambient temperature. The numerical results show that the modified design, which is provided ventilated holes at the one-sided surface of the wheel, is adequate to solve the thermal problem by improving the cooling characteristics. The numerical results show good agreement with the experimental results. Therefore, this finite element analysis of brake system can be regarded as a better quantitative and reliable simulation program.
Flight Strain Survey Test of A Basic Trainer
Park, Chan-Yik ; Hwang, Chul-Ho ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 127~127
Strain survey flight tests were performed to verify structural analysis results and to assure static safety. for these tests 32 strain gages were attached at critical areas of airframe and strain signals were processed by aircraft telemetry system. Test results were compared with analysis ones considering aircraft configuration and flight conditions. The comparison shows good agreement at the main wing and the center fuselage. For the rear fuselage and empennage strains get by tests are lower than those from analysis which are below the allowable strains. Through these tests, it is confirmed that the airframe is statically safe for the whole flight envelope.
Developmental Design on ATIS for Aircraft Simulator
Hong, Kum-Suk ; Ham, Heung-Bin ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 136~136
This paper represents developmental Design regarding the ATIS(Automatic Terminal Information Service) for providing sound effect, navigation and communication functions to aircraft simulator pilot. ATIS is the continuos broadcast or recorded non-control information in selected high activity terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential but routine information. In this paper, the system has sound database according to each environmental conditions and it is designed to effectively provide sounds bring in meteorological information. The hardware and software is to bring from such that former developed aircraft simulator. The methods in this paper can be also applied for the realization of a fully automatic ATIS.
UAV - Current and Future
Lee, Kyung-Tae ; Lee, Ki-Hak ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 6, 2000, Pages 142~142