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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Aeronautical & Space Sciences
Journal Basic Information
Journal DOI :
The Korean Society for Aeronautical & Space Sciences
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Volume & Issues
Volume 30, Issue 8 - Dec 2002
Volume 30, Issue 7 - Oct 2002
Volume 30, Issue 6 - Sep 2002
Volume 30, Issue 5 - Aug 2002
Volume 30, Issue 4 - Jun 2002
Volume 30, Issue 3 - May 2002
Volume 30, Issue 2 - Apr 2002
Volume 30, Issue 1 - Feb 2002
Selecting the target year
A Study on the Integration of Analysis Modules and the Optimization Process in the MDO Framework
Cho, Sang-Oh ; Lee, Jae-Woo ; Byun, Yung-Hwan ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 1~10
DOI : 10.5139/JKSAS.2002.30.7.001
Multidisciplinary Design Optimization (MDO) is a new design approach, which aims to reduce the design cycle and the development cost, while improving the performance of the product. In order to develop a framework software where the multidisciplinary design is possible, several methods about the analysis codes integration, the analysis and optimization process management, and the software architecture, are proposed in this study. Centralized DataBase Management System (DBMS) is adopted. Both the Dynamic Link Library(DLL) and the File Interface are suggested and implemented as analysis codes integration methods. To efficiently manage the optimization process and the data flow, the Graphic Programming approach is introduced. The proposed integration methods are verified by two test case examples: Simple house design example and the aircraft wing design problem using three dimensional Panel Code.
An Experimental Study on the Inflation Characteristics of Parachute Canopies
Oh, Se-Yoon ; Kim, Chan-Ki ; Lee, Jong-Geon ; Ahn, Seung-Ki ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 11~19
DOI : 10.5139/JKSAS.2002.30.7.011
Inflating characteristics of the parachute canopies have been experimentally investigated with the objective of measuring the parachute opening parameters such as canopy filling time and the peak opening force using scaled parachute models. A device has been made and tested to eject a model parachute into a wind tunnel flow and to measure the drag force acting on it. The force-time histories and the peak opening force are obtained, and these comparative aerodynamic characteristics were analyzed and discussed, including the effect of forebody wake. The opening of the ringslot parachute model appeared to be faster than that of the available similar data by about 10~40%, and fair to good agreement was obtained for the reefed ribbon parachute.
Aerodynamic Performance Prediction of a Counter-rotating Wind Turbine System with Wake Effect
Dong, Kyung-Min ; Jung, Sung-Nam ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 20~28
DOI : 10.5139/JKSAS.2002.30.7.020
In this paper, the aerodynamic performance prediction of a 30kW counter-rotating (C/R) wind turbine system has been made by using the momentum theory as well as the two-dimensional quasi-steady strip theory with special care on the wake and the post-stall effects. In order to take into account the wake effects in the performance analysis, the wind tunnel test data obtained for a scaled blade are used. Both the axial and rotational inductions behind the auxiliary rotors are determined through the wake model. In addition, the optimum chord and twist distributions along the blades are obtained from the Glauert`s optimum actuator disk model considering the Prandtl`s tip loss effect. The performance results of the counter-rotating wind turbine system are compared with those of the conventional single rotor system and demonstrated the effectiveness of the counter-rotating wind turbine system.
Aeroelastic Analysis of Deployable Missile Control Fin with Bilinear Nonlinearity
Bae, Jae-Sung ; Shin, Won-Ho ; Lee, In ; Shin, Young-Sug ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 29~35
DOI : 10.5139/JKSAS.2002.30.7.029
Aeroelastic characteristics of a deployable missile control fin have been investigated. A deployable missile control fin is modeled by a 2-dimensional typical section. Supersonic Doublet-Point method is used for the computation of supersonic unsteady aerodynamic forces and Karpel`s Minimum-State approximation is used for the aerodynamic approximation. Root-locus method and time-integration method are used for the linear and nonlinear flutter analyses. For the nonlinear flutter analysis the deployable hinge is represented by a asymmetric bilinear spring and is linearized by using the describing function method. From the flutter analyses, the effects of nonlinear parameters on the aeroelastic characteristics are investigated.
A New Scaling Method for Characteristics of Gas Turbine Components using Polynomial Equation
Kong, Chang-Duk ; Ki, Ja-Young ; Kang, Myoung-Cheol ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 36~43
DOI : 10.5139/JKSAS.2002.30.7.036
A new scaling method for the prediction of gas turbine components characteristics using experimental data or partially given data from engine manufacturers has been proposed. In order to minimize the analyzed performance error in the this study, firstly component maps were constructed by identifying performance data given by engine manufacturers at some operating conditions, then the simulated performance using the identified maps was compared with the performance result using the currently used traditional scaling method. In comparison, the performance result by the currently used traditional scaling method was well agreed with the real engine performance at on-design point but it had maximum 12% error at off-design points within the flight envelope of a study turboprop engine. However because the analysed performance by the newly proposed scaling method had maximum 6% reasonable error even within all flight envelope.
Analysis of low-velocity impact on composite sandwich panels using an assumed strain solid element
Park, Jung ; Park, Hoon-Cheol ; Yoon, Kwang-Joon ; Goo, Nam-Seo ; Lee, Jae-Hwa ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 44~50
DOI : 10.5139/JKSAS.2002.30.7.044
Low-velocity impact on composite sandwich panel has been investigated. Contact force is computed from a proposed modified Hertzian contact law. The Hertzian contact law is constructed by adjusting numerical value of the exponent and reducing the through-the- thickness elastic constant of honeycomb core. The equivalent transverse elastic constant is calculated from the rule of mixture. Nonlinear equation to calculate the contact force is solved by the Newton-Raphson method and time integration is done by the Newmark-beta method. A finite element program for the low-velocity impact analysis is coded by implementing these techniques and an 18-node assumed strain solid element. Behaviors of composite sandwich panels subjected to low-velocity impact are analyzed for various cases with different geometry and lay-ups. It has been found that the present code with the proposed contact law can predict measured contact forces and contact times for most cases within reasonable error bounds.
Evaluation of Performance of Atmospheric Re-Entry System for the Uncertainties Using the Monte-Carlo Simulation
Lee, Dae-Woo ; Cho, Kyeum-Rae ; Oh, Se-Jong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 51~60
DOI : 10.5139/JKSAS.2002.30.7.051
The Monte-Carlo simulation of statistical analysis is used to investigate the final conditions of states as well as the footprint boundaries resulting from the atmospheric re-entry dispersions. The re-entry dispersions in this paper are specified by a
covariance matrix of latitude, longitude, altitude, bank angle, flight path angle, heading error, and range at entry velocity. The error sources that affect these at re-entry for a deboost are the uncertainties associated with atmospheric density and temperature, initial errors, wind, and estimation error of aerodynamic coefficients. Using
deviations of these errors and a nominal flight trajectory, the covariance matrix of state variables can be determined by performing a trajectory error analysis. Major considerations in the application of the Monte-Carlo method are the simulation of perturbed trajectories, bank reversal, and determination of the impact points for each of these trajectories. This paper analyzes the results of uncertainties from the viewpoint of aero-coefficients and bank reversal.
A study on the control surface/actuator fault detection, identification, and accommodation system for aircraft
Song, Yong-Kyu ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 61~67
DOI : 10.5139/JKSAS.2002.30.7.061
In this study a control surface/actuator fault detection, identification, and accommodation system for aircraft is designed. This fault tolerant control system tries to return aircraft to its stable trim condition in a short time. The control system is designed using neural networks with Extended Back Propagation Algorithm which shows fast convergence. F-4 aircraft with possible stabilator or aileron failure/stuck is simulated with the proposed scheme.
Acceleration of LU-SGS Code on Latest Microprocessors Considering the Increase of Level 2 Cache Hit-Rate
Choi, J.Y. ; Oh, Se-Jong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 68~80
DOI : 10.5139/JKSAS.2002.30.7.068
An approach for composing a performance optimized computational code is suggested for latest microprocessors. The concept of the code optimization, called here as localization, is maximizing the utilization of the second level cache that is common to all the latest computer system, and minimizing the access to system main memory. In this study, the localized optimization of LU-SGS (Lower-Upper Symmetric Gauss-Seidel) code for the solution of fluid dynamic equations was carried out in three different levels and tested for several different microprocessor architectures most widely used in these days. The test results of localized optimization showed a remarkable performance gain up to 7.35 times faster solution, depending on the system, than the baseline algorithm for producing exactly the same solution on the same computer system.
Design of Aim Angle Following Guidance Law Using Lyapunov Theory
Kim, Ki-Seok ; Kim, You-Dan ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 81~89
DOI : 10.5139/JKSAS.2002.30.7.081
Guidance laws can be conceptually classified into three categories although their mathematical representations are various and different. In this paper, a generalized conceptual guidance law including the concepts of the above categories is proposed. The aim angle is introduced using the geometry of the collision triangle. The aim angle represents the arbitrary angle between the pursuit angle and the expected collision angle. The objective of the proposed guidance law is to make the aim angle zero asymptotically. It can be shown that the aim angle error response for the considered system is same as that of the first order system. When the autopilot of the missile system has slow dynamics, autopilot time lag may deteriorate the performance of the guidance law performance. In this case, another new guidance law compensating the autopilot time lag effect is proposed. To verify the proposed guidance laws, several numerical simulations are performed.
Development of Wall Slip Models for Rarefied Gas and MEMS Thermal Fluid Flows
Myong, Rho-Shin ; Cho, Soo-Yong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 90~97
DOI : 10.5139/JKSAS.2002.30.7.090
Wall slip models are essential to the study of nonequilibrium gas transport in rarefied and microscale condition that can be found in gas flows associated with aerospace vehicle, propulsion system, and MEMS. The Maxwell slip model has been used for this type of problem, but it has difficulty in defining the so-called accommodation coefficient and has not been very effective in numerical implementation. In the present study, on the basis of Langmuir`s theory of the adsorption of gases on metals, a physical slip model is developed. The concept of the accommodation coefficient and the difference of gas particles are clearly explained in the new model. It turned out that the Langmuir model recovers the Maxwell model in the first-order approximation. The new models are also applied to various situations including internal flow in a microchannel. Issues of validation of models are treated by comparing analytic results with experiment.
System Condensation Technique-Based Inverse Perturbation Method of Damage Detection
Choi, Young-Jae ; Lee, U-Sik ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 98~104
DOI : 10.5139/JKSAS.2002.30.7.098
System condensation technique improves the efficiency of the inverse perturbation method of damage detection developed in the previous work. The technique is applied to transform the unmeasured DOFs to the measured DOFs. This approach makes it possible to eliminate the unmeasured DOFs, which accelerates the computational efficiency. The numerical instability problems due to the system condensation technique are also resolved by updating the transformation matrix for each step, and also by adopting the accelerated improved reduced system(AIRS) condensation method.
An Investigation of the Vortical Flow Characteristics over a Yawed Delta Wing with LEX at High Incidence
Lee, Ki-Young ; Sohn, Myong-Hwan ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 105~112
DOI : 10.5139/JKSAS.2002.30.7.105
An experimental study of the vortical flow characteristics around a yawed delta wing with the leading edge extension at high incidence angle is undertaken by upper surface pressure measurements. A special emphasis has been put on analyzing the basic physics of vortical flows, concerning the effects of incidence and sideslip angle on the aerodynamic characteristics of the wing, especially under high angle of attack. The experimental data has been dearly demonstrated the beneficial effect of the LEX vortex on the wing vortex. It leads to an essential stabilization of the wing vortex against its breakdown until at much higher incidence angle under small sideslip. An interesting flow feature is occurrence of the rolling moment reversal at a certain range of angle of attack and sideslip angle.
Control System Modeling and Optimal Bending Filter Design for KSR-III First Stage
Ahn, Jae-Myung ; Roh, Woong-Rae ; Cho, Hyun-Chul ; Park, Jeong-Joo ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 113~122
DOI : 10.5139/JKSAS.2002.30.7.113
Control system modeling and optimal bending filter design for KSR-III (Korea Sounding Rocket III) are performed. Rigid rocket dynamics, aerodynamics, sloshing, structural bending, actuator dynamics, sensor dynamics and on-board computer characteristics are considered for control system modeling. Compensation for time-varying control system parameters is conducted by gain-scheduling. A filter to stabilize bending mode is designed using parameter optimization technique. Resultant attitude control system can satisfy required frequency domain stability margin.
Determination of KITSAT-3 Orbital Elements Using GPS Data from a Low-End Receiver
Lee, Eun-Sung ; Lee, Young-Jae ; Jee, Gyu-In ; Park, Chan-Gook ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 123~129
DOI : 10.5139/JKSAS.2002.30.7.123
This paper reveals determination of orbital elements of the satellite using GPS data collected by the low-end GPS receiver installed at KITSAT-3 which is a small scientific experimental satellite of Korea and launched in May 1999. An extended Kalman filter is designed for a forward estimation of real-time 3-dimensional position and velocity, and a smoother is used for a backward post-processing estimation of the same states. After finishing estimation of position and velocity, the corresponding orbital elements are estimated. Finally, the result of each orbital element is analyzed.
A Plight Test Method for the System Identification of an Unmanned Aerial Vehicle
Lee, Youn-Saeng ; Suk, Jin-Young ; Kim, Tae-Sik ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 130~136
DOI : 10.5139/JKSAS.2002.30.7.130
In this paper, a flight test method is described for the system identification of the unmanned aerial vehicle equipped with an automatic flight control system. Multistep inputs are applied for both longitudinal mode and lateral/directional excitation. Optimal time step for excitation is sought to provide the broad input bandwidth. A programmed mode flight test method provides high-quality flight data for system identification using the flight control computer with the longitudinal and lateral/directional autopilot which enables the separation of each motion during the flight test. In addition, exact actuating input that is almost equivalent to the designed one guarantees the highest input frequency attainable. Several repetitive flight tests were implemented in the calm air in order to extract the consistent system model for the air vehicle. The enhanced airborne data acquisition system endowed the high-quality flight data for the system identification. The flight data were effectively used to the system identification of the unmanned aerial vehicle.
Spin-Stabilization for the Second Stage of Korea Sounding Rocket-III
Sun, Byung-Chan ; Choi, Hyung-Don ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 137~143
DOI : 10.5139/JKSAS.2002.30.7.137
This paper concerns the spin-stabilization for the second stage of KSR-III(Korea Sounding Rocket-III). The error sources in the second stage are defined, and then the effect on attitude error of KSR-III is analyzed quantitatively and qualitatively. Based on the analysis, some conditions for optimal spinning frequency and optimal steady-spinning duration are suggested. Among several solutions, an optimal value can be determined in the point of minimum impact-point error. An approach to a sub-optimal solution is also suggested. Application to the KSR-III shows that a proper spinning frequency and a steady-spin duration to give the smallest impact-point error can be effectively determined.
A study on the parallel processing of the avionic system computer using multi RISC processors
Lee, Jae-Uk ; Lee, Sung-Soo ; Kim, Young-Taek ; Yang, Seung-Yul ; Kim, Bong-Gyu ; Hwang, Sang-Hyun ; Park, Deok-Bae ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 144~149
DOI : 10.5139/JKSAS.2002.30.7.144
This paper presents a technique for real time multiprocessor parallel processing to develop an avionic system computer(ASC) which integrates the avionics control, navigation and fire control, cursive and raster graphic symbol generation into one line replaceable unit. The proposed method has optimal performance by adopting a logically asymmetric structure between four 32bit RISC processors based on the master-slave multiprocessing, a tightly coupled interaction level with the time shared common bus and global memory, and an efficient bus arbitration algorithm. The ASC has been verified through a series of flight tests. The relevant tests also have been rigorously conducted on the prototype ASC such as electrical test, environmental test, and electromagnetic interference test.
Airplane R&D Simulator
Yoon, Sug-Joon ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 30, issue 7, 2002, Pages 150~162
DOI : 10.5139/JKSAS.2002.30.7.150