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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 39, Issue 12 - Dec 2011
Volume 39, Issue 11 - Nov 2011
Volume 39, Issue 10 - Oct 2011
Volume 39, Issue 9 - Sep 2011
Volume 39, Issue 8 - Aug 2011
Volume 39, Issue 7 - Jul 2011
Volume 39, Issue 6 - Jun 2011
Volume 39, Issue 5 - May 2011
Volume 39, Issue 4 - Apr 2011
Volume 39, Issue 3 - Mar 2011
Volume 39, Issue 2 - Feb 2011
Volume 39, Issue 1 - Jan 2011
Selecting the target year
An Experimental Study on Magnus Characteristics of a Spinning Projectile at High Speed Region
Oh, Se-Yoon ; Lee, Do-Kwan ; Kim, Sung-Cheol ; Kim, Sang-Ho ; Ahn, Seung-Ki ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 385~390
DOI : 10.5139/JKSAS.2011.39.5.385
The purpose of this research is to determine the dynamic Magnus effect data of a spinning projectile in wind-tunnel testing. In the present work, the high-speed wind-tunnel tests for the Magnus effect measurements were conducted on a 155-mm spin-stabilized projectile model in the Agency for Defense Development`s Tri-Sonic Wind Tunnel at spin rates about 12,000 rpm. The test Mach numbers ranged from 0.7 to 2.0, and the angles of attack ranged from -4 to +10 deg. The validity of the wind-tunnel measurement techniques was evaluated by comparing them with the previous test results on the same configuration. The experimental results show that fair to good agreement is obtained with resonable accuracy.
Prediction to Shock Absorption Energy of an Aluminum Honeycomb
Kim, Hyun-Duk ; Lee, Hyuk-Hee ; Hwang, Do-Soon ; Park, Jung-Sun ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 391~399
DOI : 10.5139/JKSAS.2011.39.5.391
The purpose of this paper is to predict the shock absorbing characteristics of the aluminum honeycomb in a lunar lander. Aluminum honeycomb has been used for shock absorbers of lunar lander due to its characteristics such as light weight, high energy absorption efficiency and applicability under severe space environments. Crush strength of the honeycomb should have strength to endure during shock energy absorbing process. In this paper, the crush strength, which depends on the shape of honeycomb and impact velocity, is estimated using FEM. Ls-dyna is used for finite element analysis of the honeycomb shock absorber. The unit cells of the honeycomb shape are modeled and used for the finite element analysis. Energy absorption characteristics are decided considering several conditions such as impact velocity, foil thickness and branch angle of the honeycomb.
Study for the Deformation and Fatigue Life of a PEMFC
Yang, Jeong-Hwan ; Park, Jung-Sun ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 400~407
DOI : 10.5139/JKSAS.2011.39.5.400
The stress distribution and stress amplitude of a membrane are major factors to decide the mechanical fatigue life of PEMFC (Polymer Electrolyte Membrane Fuel Cell). In this paper, mechanical stresses under operating hygro-thermal condition of the membrane are numerically modelled. Contact analysis between gas diffusion layer (GDL) and the membrane is performed under various temperature-humidity conditions. The structural model has nonlinear material properties depending on temperature and relative humidity. Several geometric conditions are applied to the model. The numerical analysis results indicate that deformations of the membrane are strongly related with assembly conditions of the fuel cell. The fatigue life is predicted for practical operating condition through experimental data.
Control of powered descent phase for a Lunar lander using PID controller
Jo, Sung-Jin ; Min, Chan-Oh ; Lee, Dae-Woo ; Cho, Kyeum-Rae ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 408~415
DOI : 10.5139/JKSAS.2011.39.5.408
The moon landing is composed of the de-orbit descent phase, powered descent phase, and the powered descent phase is divide into 3-sub phase of the braking, approach, final landing phase. In this paper, the lunar lander perform landing control using 3-sub phase of optimal trajectory. First, generate the reference trajectory using gauss pseudo-spectral method. Thereafter generate PID controller using altitude and velocity error in each direction. Finally the lunar lander landing system constitute using the Simulink of Matlab, and perform simulation.
A Study on Operation Characteristics of Co-flow Fluidic Thrust Vector Control under Over-expanded Jet Condition
Heo, Jun-Young ; Jeon, Dong-Hyun ; Lee, Yeol ; Sung, Hong-Gye ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 416~423
DOI : 10.5139/JKSAS.2011.39.5.416
The purpose of this research is to investigate the operation characteristics of fluidic thrust vector control using injection of the control flow parallel to the main jet direction; Co-flow injection. The technique bases on the Coanda effect of flow. Both numerical and experimental studies were conducted to investigate operation parameters; flow structure, the jet deflection angle, and shock effects near the nozzle exit. While the total pressure of main jet is the range of 300 to 790 kPa, the total pressure of control flow varies from 120 to 200 kPa. The jet deflection angle and thrust coefficient have linear relation with the pressure ratio(PR) of main jet to control flow in 0.15 < PR < 0.4 but show their limit above PR
Optimization of a Centrifugal Compressor Impeller(I): Shape Parameters and Design Variables
Choi, Hyoung-Jun ; Park, Young-Ha ; Ahn, Kook-Young ; Cho, Soo-Yong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 424~432
DOI : 10.5139/JKSAS.2011.39.5.424
Shape parameters and design variables for a centrifugal compressor impeller were investigated for optimizing a centrifugal compressor. In order to compare the performance of an optimized impeller with the performance of the original impeller, an already tested impeller was chosen and design variables for optimization were selected. The meridional shapes at the shroud and at the hub were re-designed using the Bezier curve. The camber-lines of the impeller blade at the hub and at the tip were also expressed by the Bezier curve. The shape curves for impeller could be expressed using 6-8 control points. Among them, eight control points which have strong effect to the shape can be selected as design variables for optimization. Therefore, any impeller which is expressed by data points for its shape can be optimized using few design variables.
Optimization of a Centrifugal Compressor Impeller(II): Artificial Neural Network and Genetic Algorithm
Choi, Hyoung-Jun ; Park, Young-Ha ; Kim, Chae-Sil ; Cho, Soo-Yong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 433~441
DOI : 10.5139/JKSAS.2011.39.5.433
The optimization of a centrifugal compressor was conducted. The ANN (Artificial Neural Network) was adopted as an optimization algorithm, and it was learned and trained with the DOE (Design of Experiment). In the DOE, it was predicted the main effect and the interaction effect of design variables to the objective function. The ANN was improved in the optimization process using the GA (Genetic Algorithm). When any output at each generation was reached a standard level, it was re-calculated by the CFD (Computational Fluid Dynamics) and it was applied to develop a new ANN. After 6th generation, the prediction difference between ANN and CFD was less than 1%. A pareto of the efficiency versus the pressure ratio was obtained through the 21th generation. Using this method, the computational time for the optimization was equivalent to the time consumed by the gradient method, and the optimized results of multi-objective function were obtained.
Measurement of Rotor Blade Deformation and Motions using Stereo Pattern Recognition Method
Park, Jae-Won ; Kim, Hong-Il ; Han, Jae-Hung ; Kim, Do-Hyung ; Song, Keun-Woong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 442~450
DOI : 10.5139/JKSAS.2011.39.5.442
A measurement system using stereo pattern recognition (SPR) method was configured to measure the rotor blade deformations and motions. An SPR-based measurement system was prepared using six stereo cameras. Through a series of experiments to evaluate the system measurement uncertainty, it was verified that the SPR system had less than 0.2mm standard uncertainty. The combined standard uncertainties for the lead-lag, flapping, and pitching motions were estimated as 0.296mm, 0.209mm, and
, respectively. The SPR system was installed at a general small-scaled rotor test system at Korea Aerospace Research Institute. The blade motions and elastic deformation were successfully measured under the conditions with rotating speeds of 360rpm or 589rpm, and collective pitch angles of
. The advantages of the SPR system was analyzed in comparison with the measurement system used in Higher Harmonic Control Aeroacoustic Rotor Test -II.
Precision exploration of space resources using laser-induced breakdown spectroscopy
Choi, Soo-Jin ; Yoh, Jai-Ick ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 451~457
DOI : 10.5139/JKSAS.2011.39.5.451
A short laser pulse irradiates a sample to create the highly energetic plasma that emits light of a specific wavelength peak according to the material. By identifying different peaks for the analyzed samples, its chemical composition can be rapidly determined. The LIBS (Laser-Induced Breakdown Spectroscopy) has great advantages as an elemental analyzer on board a space rover, namely real-time rapid analysis and stand-off detection. The LIBS signal intensity is remarkably increased by using double-pulse LIBS system for component analysis of lunar environments where the surrounding pressure is low. Also the angle of target is adjusted for replicating arbitrary shapes of the specimen.
Conceptual Study on Coaxial Rotorcraft UAV for teaming operation with UGV
Byun, Young-Seop ; Song, Jun-Beom ; Song, Woo-Jin ; Kim, Jeong ; Kang, Beom-Soo ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 458~465
DOI : 10.5139/JKSAS.2011.39.5.458
UAV-UGV teaming concept has been proposed that can compensate for weak points of each platform by providing carrying, launching, recovery and recharging capability for the VTOL-UAV through the host UGV. The teaming concept can expand the observation envelop of the UGV and extend the operational capability of the UAV through mechanical combination of each system. The spherical-shaped coaxial rotorcraft UAV is suggested to provide flexible and precise interface between two systems. Hybrid navigation solution that included vision-based target tracking method for precision landing is investigated and its experimental study is performed. Feasibility study on length-variable rotor to provide the compact configuration of the loaded rotorcraft platform is also described.
Preliminary Thermal Analysis for LEO Satellite Optical Payload`s Thermal Vacuum Test
Lee, Jongl-Yul ; Huh, Hwan-Il ; Kim, Sang-Ho ; Chang, Su-Young ; Lee, Deog-Gyu ; Lee, Seung-Hoon ; Choi, Hae-Jin ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 466~473
DOI : 10.5139/JKSAS.2011.39.5.466
The purpose of satellite thermal control design is to maintain all the elements of a spacecraft system within their temperature limits for all mission phases. The thermal analysis model for Low Earth Orbit satellite payload level simulation is established by considering thermal vacuum test environment condition, thermal vacuum chamber configuration, and satellite`s payload inner thermal environment. The established thermal analysis model is used to determine thermal vacuum test conditions and test case requirements.
Thermal Design and Analysis for Space Imaging Sensor on LEO
Shin, So-Min ; Oh, Hyun-Ung ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 39, issue 5, 2011, Pages 474~480
DOI : 10.5139/JKSAS.2011.39.4.474
Space Imaging Sensor operated on LEO is affected from the Earth IR and Albedo as well as the Sun Radiation. The Imaging Sensor exposed to extreme environment needs thermal control subsystem to be maintained in operating/non-operating allowable temperature. Generally, units are periodically dissipated on spacecraft panel, which is designed as radiator. Because thermal design of the imaging sensor inside a spacecraft is isolated, heat pipes connected to radiators on the panel efficiently transfer dissipation of the units. First of all, preliminary thermal design of radiating area and heater power is performed through steady energy balance equation. Based on preliminary thermal design, on-orbit thermal analysis is calculated by SINDA, so calculation for thermal design could be easy and rapid. Radiators are designed to rib-type in order to maintain radiating performance and reduce mass. After on-orbit thermal analysis, thermal requirements for Space Imaging Sensor are verified.