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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 42, Issue 12 - Dec 2014
Volume 42, Issue 11 - Nov 2014
Volume 42, Issue 10 - Oct 2014
Volume 42, Issue 9 - Sep 2014
Volume 42, Issue 8 - Aug 2014
Volume 42, Issue 7 - Jul 2014
Volume 42, Issue 6 - Jun 2014
Volume 42, Issue 5 - May 2014
Volume 42, Issue 4 - Apr 2014
Volume 42, Issue 3 - Mar 2014
Volume 42, Issue 2 - Feb 2014
Volume 42, Issue 1 - Jan 2014
Selecting the target year
Design optimization of the staking line for an electric fan blade using CFD
Park, Seunghwan ; Ryu, Minhyoung ; Cho, Leesang ; Cho, Jinsoo ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 903~910
DOI : 10.5139/JKSAS.2014.42.11.903
Electric fans, which consist of axial blades, are operated by the induction motor. In this paper, the objective of this study is the performance improvement of the base model fan using the design optimization. In order to aerodynamic analysis, computational simulations are performed using commercial tool ANSYS-CFX ver. 14.5. And k-
SST turbulence model is used for the CFD analysis. The design variables are set up as sweep and lean angles. Volumetric flow rate and torque of the fan blades are fixed to objective function. The optimized model is shown the increment of the volumetric flow rate and the reduction of the torque compared with the base model. The experimental procedure is followed KS C 9301. CFD results and experimental results are fairly well matched.
Selective Activation of Cohesive Elements using MPC
Woo, Kyeongsik ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 911~918
DOI : 10.5139/JKSAS.2014.42.11.911
In this paper, a selective activation strategy of cohesive elements using user subroutine UMPC was studied as an efficient solution for the added compliance problem in cohesive zone model crack propagation analyses. The cohesive elements were inserted between every bulk elements in region where cracks were expected to initiate and propagate, but initially not activated by tying the cohesive nodes using multi-point constraints. During analyses, the cohesive elements for which specified criterion was met were selectively activated by releasing the constraints. The effect of initial cohesive stiffness and the release criterion on the crack propagation behavior was carefully investigated.
Effect on Material Property on the Frature Propagation Behavior
Jeong, Jaeyeon ; Woo, Kyeongsik ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 919~926
DOI : 10.5139/JKSAS.2014.42.11.919
In this paper, the effect of material properties on fracture behavior was studied using cohesive zone model and extended finite element method. The rectangular tensile specimen with a central inclined initial crack was modeled by plane stress elements. In the CZM modeling, cohesive elements were inserted between every bulk elements in the predicted crack propagation region before analysis, while in the XFEM the enrichment to the elements was added as needed during analysis. The crack propagation behavior was examined for brittle and ductile materials. For thin specimen configuration, wrinkle deformation was accounted for by geometrically nonlinear post-buckling analysis and the effect of wrinkling on the crack propagation was investigated.
Strength Prediction on Composite Laminates Including Material Nonlinearity and Continuum Damage Mechanics
Park, Kook-Jin ; Kang, Hee-Jin ; Shin, Sangjoon ; Choi, Ik-Hyun ; Kim, Minki ; Kim, Seung-Jo ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 927~936
DOI : 10.5139/JKSAS.2014.42.11.927
This paper presents development and verification of the progressive failure analysis upon the composite laminates. Strength and stiffness of the fiber-reinforced composite are analyzed by property degradation approach with emphasis on the material nonlinearity and continuum damage mechanics (CDM). Longitudinal and transverse tensile modes derived from Hashin`s failure criterion are used to predict the thresholds for damage initiation and growth. The modified Newton-Raphson iterative procedure is implemented for determining nonlinear elastic and viscoelastic constitutive relations. Laminar properties of the composite are obtained by experiments. Prediction on the un-notched tensile (UNT) specimen is performed under the laminate level. Stress-strain curves and strength results are compared with the experimental measurement. It is concluded that the present nonlinear CDM approach is capable of predicting the strength and stiffness more accurately than the corresponding linear CDM one does.
A Study on vertical mode system identification for a single tilt wing UAV
Seo, Ilwon ; Kim, Seungkeun ; Suk, Jinyoung ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 937~946
DOI : 10.5139/JKSAS.2014.42.11.937
This paper presents system identification of a single tilt wing UAV. A Modified Equation Error Method(MEEM) and Extended Kalman Filter(EKF) are used for the identification of a single tilt wing UAV system in frequency-domain and time-domain, respectively. Simulated flight data is obtained from CNUX-3`s vertical mode linear simulation with realistic sensor noise. System identification performance is analyzed with respect to a variety of design parameters of the MEEM. Also, High accuracy Fourier Transform(HFT) is applied to enhance the performance of MEEM. The results of the MEEM is compared with those of the EKF. Design parameters of the MEEM and initial conditions of the EKF are decided from optimization.
A Study on Navigation Performance Analysis Technique of Pseudolite Navigation Systems
Park, Jun-Pyo ; Suk, Jinyoung ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 947~957
DOI : 10.5139/JKSAS.2014.42.11.947
In this paper, the navigation performance analysis techniques of a pseudolite navigation system are proposed. To validate the techniques, operation and navigation test results using real test data are addressed. The conventional navigation performance analysis methods used for satellite navigation system, such as Galileo and GPS, are analyzed to identify the error factor and to check the criterion of UERE defined in the standard document. And then the method to calculate the UERE through the ranging measurements are studied. By identifying the error factor in pseudolite navigation system based on these methods, the available UERE observation and calculation method applicable to pseudolite navigation are proposed. Simulation results considering various circumstances and the actual flight test results are presented to verify the proposed method.
A Hybrid RCS Analysis Code Based on Physical Optics and Geometrical Optics
Jang, Min-Uk ; Myong, Rho-Shin ; Jang, In-Mo ; Lee, Dong-Ho ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 958~967
DOI : 10.5139/JKSAS.2014.42.11.958
A hybrid method based on high-frequency asymptotic optics was developed in order to predict the RCS of flying vehicles for RCS reduction studies. In cavity return, the rays are assumed to bounce from the inlet cavity based on the laws of geometrical optics and to exit the cavity via the aperture. In other parts of a flying vehicle, the physical optics method is applied to compute the back-scattered field from the solid surface. The hybrid method was validated by considering simple models of sphere and sphere with cavity. In addition, RCS analysis of a flying vehicle was conducted using the new hybrid electromagnetic scattering method based on physical optics and geometrical optics theories.
Automatic Flight Control System Development for Optionally Piloted Vehicle
Lee, Sangjong ; Choi, Hyoung Sik ; Seong, Kie-Jeong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 968~973
DOI : 10.5139/JKSAS.2014.42.11.968
Optionally Piloted Vehicle is one of the UAV development technology and method, which can provide the economic and efficient unmanned system. Existing manned aircraft is evaluated through much flight operations and it can supply the reliable aircraft platform, engine and subsystems for operation. In addition, OPV can be operated both manned and unmanned vehicle to satisfy the mission requirement. under the certain flight conditions. This paper describes main development procedures for automatic flight control system of OPV and summarizes the technical issues and results.
Cathode Power Development of Hall Thruster for Small Satellite using Microwave cathode
Kang, Seokhyun ; Choo, Wongyo ; Choi, Junku ; Jeong, Yunhwang ; Kim, Younho ; Kang, Seongmin ; Kuninaka, Hitoshi ; Cha, Hanju ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 974~980
DOI : 10.5139/JKSAS.2014.42.11.974
A power supply of cathode has been developed for hall-effect thruster for small satellite. A microwave cathode has been applied to the electric propulsion system and cathode power is necessary in oder to work securely. Anode current is varied by a flow rate controlled by anode tank pressure. Then cathode current has to be controled in proportion by anode current. So cathode power supply has been designed to offer a current proportional to anode current. Also cathode power has been tuned to work securely for cathode to emit more electron than anode within 0.03A. The function test of cathode power was performed by constructing an equivalent load for anode and cathode. It has been tested in a vacuum chamber in order to ensure a stable operation of the thruster. And it was confirmed that thruster normally has been operated in the space environment after the launch.
TID and SEGR Testing on MOSFET of DC/DC Power Buck Converter
Lho, Young Hwan ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 981~987
DOI : 10.5139/JKSAS.2014.42.11.981
DC/DC switching power converters are commonly used to generate a regulated DC output voltage with high efficiency. The DC/DC converter is composed of a MOSFET (metal-oxide semiconductor field effect transistor), a PWM-IC (pulse width modulation-integrated circuit) controller, inductor, capacitor, etc. It is shown that the variation of threshold voltage and the breakdown voltage in the electrical characteristics of MOSFET occurs by radiation effects in TID (Total Ionizing Dose) testing at the low energy
, and 5 heavy ions make the gate of MOSFET broken in SEGR (Single Event Gate Rupture) testing. TID testing on MOSFET is accomplished up to the total dose of 40 krad, and the cross section(
) versus LET(MeV/mg/
) in the MOSFET operation is studied at SEGR testing after implementation of the controller board.
Investigation of Micro-vibration Isolation Performance of SMA Mesh Washer Isolator for Vibration Isolation of X-band Antenna
Jeon, Su-Hyeon ; Kwon, Sung-Choel ; Kim, Dae-Kwan ; Oh, Hyun-Ung ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 42, issue 11, 2014, Pages 988~995
DOI : 10.5139/JKSAS.2014.42.11.988
Two axis gimbal type X-band antenna system has been widely used to effectively transmit the real time image data from the observation satellite to the ground station. The micro-vibration generated by stepping motor actuation and imperfect intermeshed gear configuration of the antenna is one of the sources to degrade the image quality. To guarantee a high quality image of high resolution observation satellite, micro-vibration isolation of X-band antenna is required. In this paper, the X-band antenna vibration isolation system using pseudoelastic SMA(Shape Memory Alloy) mesh washer has been newly suggested. The basic characteristics of the SMA mesh washer isolator proposed in this study has been measured through static load tests and its effectiveness has been demonstrated by the micro-vibration isolation test of the X-band antenna.