권호 표지

International Journal of Aeronautical and Space Sciences

한국항공우주학회 (The Korean Society for Aeronautical and Space Sciences)

  • 계간
  • /
  • 2093-274X(pISSN)
  • /
  • 2093-2480(eISSN)

과학기술표준분류

  • 기계 ＞ 항공시스템
  • 기계 ＞ 우주발사체

Aim & Scope

Founded in 2010, the International Journal of Aeronautical and Space Sciences (IJASS) has represented KSAS in introducing the academic excellence of Korean aerospace scientists and engineers to the world. Under the title of KSAS International Journal, it had been published twice a year before the publication frequency was increased to four times a year in 2010. To encourage the participation of international colleagues, its name was also changed to IJASS in 2009. Thanks to the strong support of the Korean Federation of Science and Technology Societies, the production quality has been significantly improved since 2011. Furthermore, to modernize the review system and production process, KSAS entered into a contract with Springer to co-publish IJASS, starting from Vol. 19 (1), 2018. IJASS has been listed on Science Citation Index Expanded (SCIE) since Vol .13 (1), 2012. IJASS invites high quality papers from international colleagues in all technical areas of aerospace engineering. Colleagues who are willing to serve as a member of the IJASS Editorial Board are encouraged to write to the Editor-in-Chief or the Technical Editor responsible for the field of interest. All papers published on the back issues from 2010 to 2017 can be freely accessed and downloaded at - http://ijass.org/ IJASS is published on the 30th of March, June, September and December. In 2021, IJASS is published on the last day of February, April, June, August, October and December.

http://ijass.org KSCI KCI SCOPUS

제8권2호

  1. Song, Chi-Su;Park, Seung-O 1
    https://doi.org/10.5139/IJASS.2007.8.2.001 PDF KSCI
    A two-dimensional backward facing step flow was comptuted using a Detached Eddy simulation(DES) based on the SST turbulence model. The expansion ratio(ER) was 1.125 and the Reynolds number based on the step height and the mean velocity in the upstream channel was 37,500. The flow condition was the same as with the experimental research[1]. The reattachment length, oscillatory characteristics of the flow and the coherent structures of the present simulation were compared to demonstrate the improtance of spanwise grid spacing.
  2. Hwang, In-Seong;Lee, Yun-Han;Kim, Seung-Jo 11
    https://doi.org/10.5139/IJASS.2007.8.2.011 PDF KSCI
    This paper describes the cycloidal wind turbine, which is a straight blade vertical axis wind turbine using the cycloidal blade system. Cycloidal blade system consists of several blades rotating about an axis in parallel direction. Each blade changes its pitch angle periodically. Cycloidal wind turbine is different from the previous turbines. The wind turbine operates with optimum rotating forces through active control of the blade to change pitch angle and phase angle according to the changes of wind direction and wind speed. Various numerical experiments were conducted to develop a small vertical axis wind turbine of 1 kW class. For this numerical analysis, the rotor system equips four blades consisting of a symmetric airfoil NACA0018 of 1.0m in span, 0.22m in chord and 1.0m in radius. A general purpose commercial CFD program, STAR-CD, was used for numerical analysis. PCL of MSC/PATRAN was used for efficient parametric auto mesh generation. Variables of wind speed, pitch angle, phase angle and rotating speed were set in the numerical experiments. The generated power was obtained according to the various combinations of these variables. Optimal pitch angle and phase angle of cycloidal blade system were obtained according to the change of the wind direction and the wind speed. Based on data obtained from the above analysis, control device was designed. The wind direction and the wind speed were sensed by a wind indicator and an anemometer. Each blades were actuated to optimal performance values by servo motors.
  3. Roh, Kyoung-Min;Park, Sang-Young;Choi, Kyu-Hong;Lee, Sang-Uk 17
    https://doi.org/10.5139/IJASS.2007.8.2.017 PDF KSCI
    Minimum-time attitude maneuvers of three-axis stabilized spacecraft are presented to study the feasibility of using three magnetic torquers perform large angle maneuvers. Previous applications of magnetic torquers have been limited to spin-stabilized satellites or supplemental actuators of three axis stabilized satellites because of the capability of magnetic torquers to produce torques about a specific axes. The minimum-time attitude maneuver problem is solved by applying a parameter optimization method for orbital cases to verify that the magnetic torque system can perform as required. Direct collocation and a nonlinear programming method with a constraining method by Simpson's rule are used to convert the minimum-time maneuver problems into parameter optimization problems. An appropriate number of nodes is presented to find a bang-bang type solution to the minimum-time problem. Some modifications in the boundary conditions of final attitude are made to solve the problem more robustly and efficiently. The numerical studies illustrate that the presented method can provide a capable and robust attitude reorientation by using only magnetic torquers. However, the required maneuver times are relatively longer than when thrusters or wheels are used. Performance of the system in the presence of errors in the magnetometer as well as the geomagnetic field model still good.
  4. Kanazaki, Masahiro;Yamamoto, Kazuomi;Tanaka, Kentaro;Jeong, Shin-Kyu 28
    https://doi.org/10.5139/IJASS.2007.8.2.028 PDF KSCI
    A multi-objective design exploration for a three-element airfoil consisted of a slat, a main wing, and a flap was carried out. The lift curve improvement is important to design high-lift system, thus design has to be performed with considered multi-angle. The objective functions considered here are to maximize the lift coefficient at landing and near stall conditions simultaneously. Kriging surrogate model which was constructed based on several sample designs is introduced. The solution space was explored based on the maximization of Expected Improvement (EI) value corresponding to objective functions on the Krigingmodels. The improvement of the model and the exploration of the optimum can be advanced at the same time by maximizing EI value. In this study, a total of 90 sample points are evaluated using the Reynolds averaged Navier-Stokes simulation(RANS) for the construction of the Kriging model. In order to obtain the information of the design space, two data mining techniques are applied to design result. One is functional Analysis of Variance(ANOVA) which can show quantitative information and the other is Self-Organizing Map(SOM) which can show qualitative information.
  5. Kim, Hee-Seob;Kim, Gyu-Sun;Chung, Dae-Won;Kim, Eung-Hyun 37
    https://doi.org/10.5139/IJASS.2007.8.2.037 PDF KSCI
    Coordination of multiple UAVs is an essential technology for various applications in robotics, automation, and artificial intelligence. In general, it includes 1) waypoints assignment and 2) trajectory generation. In this paper, we propose a new method for this problem. First, we modify the concept of the standard visibility graph to greatly improve the optimality of the generated trajectories and reduce the computational complexity. Second, we propose an efficient stochastic approach using simulated annealing that assigns waypoints to each UAV from the constructed visibility graph. Third, we describe a method to detect collision between two UAVs. FinallY, we suggest an efficient method of controlling the velocity of UAVs using A* algorithm in order to avoid inter-UAV collision. We present simulation results from various environments that verify the effectiveness of our approach.
  6. Jung, Mun-Seung;Kwon, Oh-Joon;Kang, Hee-Jung 44
    https://doi.org/10.5139/IJASS.2007.8.2.044 PDF KSCI
    A three-dimensional viscous flow solver has been developed for the prediction of the aerodynamic performance of hovering helicopter rotor blades using unstructured hybrid meshes. The flow solver utilized a vertex-centered finite-volume scheme that is based on the Roe's flux-difference splitting with an implicit Jacobi/Gauss-Seidel time integration. The eddy viscosity are estimated by the Spalart- Allmaras one-equation turbulence model. Calculations were performed at three operating conditions with varying tip Mach number and collective pitch setting for the Caradonna-Tung rotor in hover. Additional computations are made for the UH-60A rotor in hover. Reasonable agreements were obtained between the present results and the experiment in both blade loading and overall rotor performance. It was demonstrated that the present vertex-centered flow solver is an efficient and accurate tool for the assessment of rotor performance in hover.
  7. Ro, Kap-Seong;Oh, Jun-Seok 54
    https://doi.org/10.5139/IJASS.2007.8.2.054 PDF KSCI
    Traffic and emergency monitoring systems are essential constituents of Intelligent Transportation System (ITS) technologies, but the lack of traffic monitoring has become a primary weakness in providing prompt emergency services. Demonstrated in numerous military applications, unmanned aerial vehicles (UAVs) have great potentials as a part of ITS infrastructure for providing quick and real-time aerial video images of large surface area to the ground. Despite of obvious advantages of UAVs for traffic monitoring and many other civil applications, it is rare to encounter success stories of UAVs in civil application including transportation. The objective of this paper is to report the outcomes of research supported by the state agency in US to investigate the feasibility of integrating UAVs into urban highway traffic monitoring as a part of ITS infrastructure. These include current technical and regulatory issues, and possible suggestions for a future UAV system in civil applications.
  8. Cho, Sang-Bum;McClamroch, N. Harris 67
    https://doi.org/10.5139/IJASS.2007.8.2.067 PDF KSCI
    An attitude control problem for a tethered spacecraft is studied. The tethered spacecraft is viewed as a multi-body spacecraft consisting of a base body, a massless tether that connects the base body and an end mass, and tether actuator dynamics. Moments about the pitch and roll axes of the base spacecraft arise by control of the point of attachment of the tether to the base spacecraft. The control objective is to stabilize the attitude of the base spacecraft while keeping the perturbations of the tether small. Analysis shows that linear equations of motion for the tethered spacecraft are not completely controllable. We study two different control design approaches: (1) we decouple the attitude dynamics from the tether dynamics and we design a linear feedback to achieve stabilization of the attitude dynamics, and (2) we decouple the controllable modes from the uncontrollable mode using Kalman decomposition and we design a linear feedback to achieve stabilization of the controllable modes. Simulation results show that, although it is difficult to control the tether, the tether motion can be maintained within an acceptable range while stabilizing the attitude dynamics of the base spacecraft.
  9. Kim, Eun-Ho;Roh, Jin-Ho;Lee, In 76
    https://doi.org/10.5139/IJASS.2007.8.2.076 PDF KSCI
    The fiber reinforced laminated composite structures are very susceptible to be damaged when they are impacted by foreign objects. To increase the impact resistance of the laminated composite structures, shape memory alloy(SMA) thin film is embedded in the structure. For the numerical impact analysis of SMA hybrid composite structures, SMA modeling tool is developed to consider pseudoelastic effect of SMAs. Moreover, the damage analysis is considered using failure criteria and a simple damage model for reasonable impact analysis. The numerical results are verified with the experimental ones. Impact analyses for composite plate with pre-strained SMAs are numerically performed and the damage areas are investigated.
  10. Woo, Ji-Hye;Rho, Jin-Ho;Lee, In 82
    https://doi.org/10.5139/IJASS.2007.8.2.082 PDF KSCI
    Thermal Buckling and free vibration analyses of multi-layered composite conical shells based on a layerwise displacement theory are performed. The Donnell's displacement-strain relationships of conical shell structure are applied. The natural frequencies are compared with the ones existing in the previous literature for laminated conical shells with several cone semi-vertex angles. Moreover, the thermal buckling behaviors of the laminated conical shell are investigated to consider the effect of the semi-vertex angle, subtended angle, and radius to thickness ratio on the structural stability.
  11. No, Tae-Soo;Lee, Sang-Uk;Kim, Sung-Ju 89
    https://doi.org/10.5139/IJASS.2007.8.2.089 PDF KSCI
    COMS(Communication, Oceanography, and Meteorology Satellite) is the first Korean multi-purpose satellite which is planned to be deployed at the altitude of geosynchronous orbit above the Korean peninsular. Noting that COMS is composed of the main BUS structure, two deployable solar panels, one yoke, five reactions wheels, COMS is treated as a collection of 9 bodies and its nonlinear equations of motion are obtained using the multi-body dynamics approach. Also, a computer program is developed to analyze the COMS motion during the various mission phase. Quite often, the equations of motion have to be derived repeatedly to reflect the fact that the spacecraft dynamics change as its configuration, and therefore its degree of freedom varies. However, the equations of motion and simulation software presented in this paper are general enough to represent the COMS dynamics of various configurations with a minimum change in input files. There is no need to derive the equations of motion repeatedly. To show the capability of the simulation program, the spacecraft motion during the solar array partial and full deployment has been simulated and the results are summarized in this paper.
  12. Sohn, Myong-Hwan;Chung, Hyoung-Seog 98
    https://doi.org/10.5139/IJASS.2007.8.2.098 PDF KSCI
    The vortex flow characteristics of a double-delta wing, which can change the incidence angle of its apex strake was investigated through the wing-surface pressure measurement and the particle image velocimetry(PIV) measurement of the wing-leeward flow region. The apex strake has sharp edges and can change its incidence angle with a hinge line at the 23% chord position measured from the apex of the main wing. The present study revealed that the incidence-angle change of the apex strake could greatly alter the vortex flow pattern around the double-delta wing and the wing-surface pressure distribution, which suggested that the apex strake could be used as an effective device for the active control of delta-wing vortex flow.
  13. Lee, Jin-Wook;Kim, H.-Jin 107
    https://doi.org/10.5139/IJASS.2007.8.2.107 PDF KSCI
    Coordination of multiple UAVs is an essential technology for various applications in robotics, automation, and artificial intelligence. In general, it includes 1) waypoints assignment and 2) trajectory generation. In this paper, we propose a new method for this problem. First, we modify the concept of the standard visibility graph to greatly improve the optimality of the generated trajectories and reduce the computational complexity. Second, we propose an efficient stochastic approach using simulated annealing that assigns waypoints to each UAV from the constructed visibility graph. Third, we describe a method to detect collision between two UAVs. FinallY, we suggest an efficient method of controlling the velocity of UAVs using A* algorithm in order to avoid inter-UAV collision. We present simulation results from various environments that verify the effectiveness of our approach.
  14. Lee, Kyung-Jae;Lee, Bo-Hwa;Kang, Sang-Hun;Jung, Jae-Hong;Yang, Soo-Seok;Lee, Dae-Sung;Kwak, Jae-Su 121
    https://doi.org/10.5139/IJASS.2007.8.2.121 PDF KSCI
    In late 1960's, engineers of the engine manufacturer experienced that the distortion of inlet flow of turbofan and turbojet engine could cause the surge in compressor and affect overall engine operational performance, which result in the deterioration of stability of the engine. In this study, block type of inlet distortion simulating device has been developed in order to investigate the effect of inlet distortion on the deterioration of overall engine operational performance. The inlet distortion simulating device was installed in front of engine inlet in order to simulate distortion of inlet flow. The degree of inlet distortion was measured by rakes installed upstream the inlet distortion simulating device and between the engine inlet and inlet distortion simulating device. Before applying the inlet distortion simulating device to real engine, preliminary tests were performed with a simulated engine in order to verify the degree of inlet distortion by the device. Preliminary inlet distortion tests were performed in Altitude Engine Test Facility(AETF) of Korea Aerospace Research Institute(KARI) and results showed that the inlet distortion simulating device could be used in simulating various inlet distortion cases.
  15. Lee, Bo-Hwa;Lee, Kyung-Jae;Yang, In-Young;Yang, Soo-Seok;Lee, Dae-Sung 126
    https://doi.org/10.5139/IJASS.2007.8.2.126 PDF KSCI
    In this paper, Monte Carlo Simulation (MCS) method was used as an uncertainty assessment tool for air flow, net thrust measurement. Uuncertainty sources of the net thrust measurement were analyzed, and the probability distribution characteristics of each source were discussed. Detailed MCS methodology was described including the effect of the number of simulation. Compared to the conventional sensitivity coefficient method, the MCS method has advantage in the uncertainty assessment. The MCS is comparatively simple, convenient and accurate, especially for complex or nonlinear measurement modeling equations. The uncertainty assessment result by MCS was compared with that of the conventional sensitivity coefficient method, and each method gave different result. The uncertainties in the net thrust measurement by the MCS and the conventional sensitivity coefficient method were 0.906% and 1.209%, respectively. It was concluded that the first order Taylor expansion in the conventional sensitivity coefficient method and the nonlinearity of model equation caused the difference. It was noted that the uncertainty assessment method should be selected carefully according to the mathematical characteristics of the model equation of the measurement.