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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 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
Wind Tunnel Test for WIG Aerodynamics
Ra, Seung-Ho ; Jeong, Jin-Deok ; Ok, Ho-Nam ; Gwon, Gi-Jeong ; Jo, Tae-Hwan ; Choe, In-Ho ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 1~1
The wind tunnel test for investigating the aerodynamic characteristics of an air cushion type WIG (Wing-In-Ground Effect) was performed. The effect of configuration change, which included the combination of three end plates, two skegs and the adaption font and rear plates, was tested. The effect of Reynolds number, flap deflection and horizontal tail incidence was also tested. Irodov's criterion for longitudinal static stability was calculated using a measured data set.
Unsteady Transonic Flow Analysis over an Oscillating Airfoil
Oh, Tae-Hoon ; Kim, Sang-Dug ; Song, Dong-Joo ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 10~10
The unsteady time accurate transonic viscous flow over an oscillating airfoil has been analyzed. The CSCM(Conservative Supra Characteristic Method) upwind flux difference splitting method with an iterative time marching scheme having first and second order accuracy in time and second order accuracy in space were applied on dynamic meshes. A steady inviscid flow over NACA 0012 airfoil has been calculated for the verification of new scheme. The first and second order time accurate unsteady calculations have been done for NACA 0012 airfoil oscillating around quarter chord on dynamic meshes. The results have been compared well with the AGARD Case 3 experimental data. The periodic characteristics have been compared with the experimental results.
Direct Simulation Monte-Carlo Analysis of Low-Enthalpy Rarefied Scramjet Inlet Flow
Chung, Chan-Hong ; Kim, Kyung-Hoe ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 18~18
A hypersonic rarefied flow around a scramjet inlet engine model has been analyzed using the Direct Simulation Monte-Carlo (DSMC) Method which is based on the Monte-Carlo statistical sampling technique. Calculations are made for a two-dimensional scramjet inlet model, corresponding to a flow condition referred to as low-enthalpy air with stagnation temperature of
at a freestream Mach numer
, due to the limitations in computational requirements. Results are compared with experimental data and those obtained by a continuum method found in the literatures. It has been shown that the DSMC method is very useful to analyze a hypersonic rarefied flow in which are present rarefied gas effects such as a slip at surface and thermal nonequilibrium due to low-density. Results obtained by the DSMC method showed better agreement with the experimental data than those obtained by the continuum method using the Navier-Stokes equations.
A Comparative Study of Different Upwind Schemes in Inviscid Transonic and Supersonic Flowfields
Kim, Moon-Sang ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 26~26
A comparative study of different upwind schemes's characteristics is accomplished using the two-dimensional inviscid flow solver in the different flow speed regions. This flow solver which solves compressible Euler equations is developed based on the finite volume method. SW's FVS, van Leer's FVS, and Roe's FDS are built in this solver to compare the differences among these three schemes. The MUSCL approach is used to increase the accuracy in space and an approximately factorized implicit scheme which was introduced by Beam & Warming is used to increase the time step margin. Three test cases are selected; one is the transonic flowfield around NACA 0012 at
. The other is the supersonic flowfield around a circular cylinder at
. The Roe's FDS is observed as the most efficient scheme from the viewpoint of solution accuracy and convergence rate in the transonic flowfield. On the other hand, the van Leer's FVS is observed as the most efficient scheme in the supersonic flowfield. The Roe's FDS gives a numerical instability in forming the shock in the supersonic flowfield. The SW's FVS is the most diffusive in both transonic and supersonic flowfields.
On Coupling the Navier-Stokes Equations with the Turbulent Model Equations
Lee, Seung-Soo ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 35~35
Two methods for coupling the Navier Stokes equations with the
turbulent model equations have been studied; namely they are a loosely coupled method and a strongly coupled method. The loosely coupled method first solves the Navier-Stokes equation with the turbulent viscosity fixed. In the subsequent step, the turbulent model equations are solved with all flow quantities fixed. On the other hand, the strongly coupled method solves the Navier-Stokes equations and the turbulent model equations simultaneously. In this paper, the stability analysis of both methods is performed. Also, the performance of two methods is compared through numerical tests. Furthermore, the influence on the convergence characteristics when using the high Reynolds form of the model is examined.
Damage Detection of Structures Based on Frequency Response Functions
Hwang, Ho-Yon ; Lee, Joong-Yup ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 46~46
In this paper, three kind of methods that find locations and amount of damage in the structures have developed using frequency response functions that can be easily obtained from the vibration measurement. Method 1 had the defect of increasing computation when a structure has damages in more than two locations and method 2 created a problem when stiffness matrices have repeated elements. In method 3, the most general method has been used which identifies damages of structure using the minimum number of frequency response functions and unknowns. To verify proposed methods, examples were presented for each method, and finally, method 3 was applied to the helicopter rotor blade which was modeled as a ,beam.
Accelerated Condensation Methods for Dynamic Analysis of A Large Structure
Kang, Myung-Ku ; Kim, Ki-Ook ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 58~58
The dynamic analysis of large structural systems takes much computing time. The optimal structural design may involve repeated analysis and hence require more cost. In general, lower modes dominate the dynamic behaviors of a structure. The application of reduction schemes for the calculation of lower modes has been an important subject in the dynamic analysis of a structure. In the present study, the higher-order terms in the series expansion of the transformation are included to accelerate the convergence of the method of improved reduced system and succession-level approximate reduction. Numerical examples show promising results for the convergence improvement.
A Modified Mixed Finite Element for Crack Problem
Kim, Won-Jung ; Kim, Yong-Hyup ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 64~64
A simple formulation is presented for efficient modeling of the 2-dimensional crack tip singularity by using mixed finite element. The mixed finite element formulation is constructed on the basis of the Hellinger-Reissner Variational Principle with two independent fields of assumed displacement and assumed strain. It is a mixed element with 3-node in each inplane direction and crack tip stress. singularity is represented by including singularity effect not only in the displacement-based strain fields but also in the independently assumed strain fields. In other words, the singularity is effectively included in the displacement-based strain fields by shifting the mid-side node to the 1/4 point, and in the independently assumed stram fields by multiplying the singularity terms
. The accuracy and efficiency of the present approach for modeling of stress singularities near the crack tip are demonstrated by means of numerical examples based on linear elastic fracture mechanics.
Impact Location Detection of Smart Composite Laminates Using Neural Networks
Sung, Dae-Un ; Oh, Jung-Hun ; Kim, Chun-Gon ; Hong, Chang-Sun ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 71~71
The impact monitoring techniques provide diagnostics of smart composite structures in which low-velocity impact can cause extensive delaminations. In this paper, we discuss the impart location detection process in which impact generated acoustic signals are detected by PZT. This non-linear inverse problem solved by MLP Neural networks. The better results could be made using the MLP with the Levenberg-Marquadt algorithm and the improving generalization methods. These methods applied to detect the location of impacts for a fully clamped aluminum rectangular plate and composite laminates subjected to transverse impacts.
Parametric Study on the Crippling Stress of Composite Stiffeners
Kweon, Jin-Hwe ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 80~80
This paper addresses the nonlinear finite element method for the crippling analysis of composite laminated stiffeners. Stiffener is idealized using nine-node laminated shell element based on the updated Lagrangian formulation. Stiffness degradation by local failure is simulated by the complete unloading model. A modified arc-length algorithm is incorporated into the nonlinear finite element method to trace the post-failure equilibrium path after local buckling. Finite element results are compared with those by experiments and show the excellent correlation. The parametric study is performed to assess the effect of the flange width, web height and stacking sequence on the crippling and buckling stress of stiffeners.
Thermo-Viscoelastic Analysis of Composite Cylinders
Chae, Dong ; Lee, Soo-Yong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 88~88
Thermo-viscoelastic analysis is performed to investigate the stress relaxation and viscoelastic behavior of thick composite cylinders. A linear viscoelastic governing equation for the composite cylinder is derived based oil the generalized plane strain theory and analytical solutions are obtained by using the Laplace transform. Viscoelastic stresses and displacements are calculated for the cross-ply and quasi-isotropic cylinders under thermal loading and compared with elasticity solutions. It is found that, as the time changes, the stresses in all the layers of the composite cylinder are not always relaxed but increased in some layers. Such a phenomenon is changed by fiber orientation.
A Study on the transmission technique of KOMPSAT TTC signal using PCM/PSK/PM multiple modulation method
Kim, Young-Wan ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 97~97
The theoretical analysis for transmission technique of TTC signal using PCM/PSK/PM multiple modulation is represented in this paper Also the method to determine the optimal subcarrier frequency and modulation index is represented based on the receiving capability for TTC signal. Furthermore, the optimal transmission technique for 1.5Mbps playback data is proposed in satellite motion environment. The available frequencies of subcarriers and modulation indexes by the proposed method show subcarrier frequencies of 16kHz, 262.144kHz for telecommand and telemetry, and 1.0, 0.8rad for telecommand and telemetry, respectively. The modulation indexes for range measurement signal are 1.0 and 0.4rad for major tone and minor tone signal, respectively. The transmission method for 1.5Mbps playback data is the PCM/BPSK/PM method, and shows 2.2rad and 1.5MHz for modulation index and subcarrier frequency, respectively. The proposed transmission techniques of KOMPSAT TTC signal represent enough gain margins of 23.43 to 36.75dB, and range accuracy characteristic within 3 meters.
Guidance and Control of Longitudinal/Lateral Trajectory for Atmosphere Re-entry Space Vehicle Using Feedback Linearization Control Law
Lee, Dae-Woo ; Cho, Kyeum-Rae ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 108~108
Several advanced countries have researched on guidance and control of atmosphere reentry. However, the scheme to obtain control law of bank angle from linearized differential equation as in space shuttle is complicated to calculate a gain and needed to adjust a control law when reference trajectory is changed. From these point of view, this scheme has shortcoming of much effort and time. In this paper, we apply the feedback linearization law, one of nonlinear control methods, to guidance and control for the model Hope-X. This paper proposes initial condition constraint considering a dynamic performance of space vehicle compared with other researchers for more accurate flight permissible boundary and shows the performance of the proposed trajectory control and verifies the importance of lateral trajectory control. The lateral error means azimuth error.
Sliding Mode Tracking Control Law of Underactuated Axisymmetric Spacecraft
Kim, Sung-Pil ; Kim, You-Dan ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 118~118
A sliding mode tracking control law for an axisymmetric rigid spacecraft which has only two control torques is proposed. The uncontrolled principal axis is assumed to be the axis of symmetry and the spin rate along the axis is zero initially. The proposed method addresses the complete system, i.e., dynamics and kinematics. The structure of the system in cascade form is used to provide a tracking control law systematically. This method has an advantage such that various reaching conditions can be used. Numerical examples demonstrate the feasibility of the method.
Acoustic Test of a Large Communication Satellite
Park, Jeong-Seok ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 130~130
The objectives of acoustic test are to determine the random vibration level of the satellite components and to demonstrate the structural integrity of the satellite components under the acoustic environment of a launch vehicle. This paper presents experimental results of acoustic test of a large communication satellite. Acceleration responses measured during the acoustic test are compared with the random vibration inputs for components level test. Those responses higher than the inputs for random vibration protoflight tests are discussed to check that the related components are overloaded during the acoustic test. The direct loads on those components are conservatively calculated and compared to the allowable loads. The experimental results shows that there was no damage or degradation to the satellite structure during the acoustic test and the test was successful.
A study on the engine inlet shape by using optimal Design
Jeon, Wan-Ho ; Lee, Duck-Joo ; Sung, Chun-Ho ; Kwon, Jang-Hyuk ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 137~137
A computer program to design an optimal shape of engine inlet is developed. It is based on a computationally efficient thin-shell BEM with a numerical optimization algorithm. The design goal in the present study is to obtain the engine inlet shape which radiates the minimum far field acoustic pressure. To do this, the far field acoustic pressure is used as objective function and the design sensitivity is obtained by finite-difference method. Finally, engine inlet design are performed with various constraint and the results are compared with scarf inlet shape.
A Study on Acceleration of Thermal Vacuum Test and its Numerical Simulation
Kim, Ji-Young ; Lee, Dong-Ho ; Choi, Joon-Min ; Choi, Seok-Weon ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 145~145
The techniques to accelerate thermal vacuum tests were investigated. This study is based on the results of thermal vacuum test for CSSA(Coarse Sun Sensor Assembly) which was performed at KARI. CSSA is a spacecraft component which was developed in Korea as a part of KOMPSAT(Korea Multi-Purpose Satellite) program. The test results were compared with the predictions from numerical analysis. The acceleration techniques and test-requisites, such as over-heating/cooling, heat transfer by direct contact, selection of low thermal mass material, etc., were introduced and discussed. Under conditions considered in this study, the test duration has been shortened up to one fifth of normal testing time depending on the test requisites and techniques.
A Preliminary Design Study of the Koparapoint System
Kang, Wi-Hun ; Park, Jong-Sou ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 28, issue 2, 2000, Pages 154~154
After reviewing the potential application of parafoil, Koparapoint, which can be considered as an effective autonomous payload delivery system, Koparapoint is studied and designed for the tethered flight test. The requirement of Koparapoint X-1 is to carry the payload of
which can penetrate the head wind of 30Knots. Koparapoint consists of parafoil system, guidance and control package, and packing apparatus. Penetration capability has been shown through the parametric analysis, and the partial ground validation test of guidance and control package has been carried out.