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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 43, Issue 12 - Dec 2015
Volume 43, Issue 11 - Nov 2015
Volume 43, Issue 10 - Oct 2015
Volume 43, Issue 9 - Sep 2015
Volume 43, Issue 8 - Aug 2015
Volume 43, Issue 7 - Jul 2015
Volume 43, Issue 6 - Jun 2015
Volume 43, Issue 5 - May 2015
Volume 43, Issue 4 - Apr 2015
Volume 43, Issue 3 - Mar 2015
Volume 43, Issue 2 - Feb 2015
Volume 43, Issue 1 - Jan 2015
Selecting the target year
Performance Evaluation of Propeller for High Altitude by using Experiment and Computational Analysis
Park, Donghun ; Cho, Taehwan ; Kim, Cheolwan ; Kim, Yangwon ; Lee, Yunggyo ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1035~1047
DOI : 10.5139/JKSAS.2015.43.12.1035
Wind tunnel experiment and computational analysis have been carried out to evaluate the performance of propeller for scale electric-powered HALE UAV, named EAV-2H+. Performance curves are measured for three propellers and their adequacy for EAV-2H+ installation is examined through consideration of operating conditions. Decline in performance coefficients is observed in low rpm region. Also, the effect of transition tape on propeller performance is measured and analyzed. The computational performance analyses are carried out by using commercial CFD program. The thrust and power coefficient from computations show good agreement with experimental results. Performance coefficients are compared and the influence of measurement device which contributes to discrepancy of the results is examined. Transition SST model is confirmed to yield the tendency of performance decline in low rpm range, similar to experimental observation. The decrease in aerodynamic performance of blade element due to low Reynolds number is identified to cause the decline in propeller performance. Analyses for high altitude conditions confirms degradation in propeller performance.
A Study on Surface Properties of Ablative Materials from 0.4MW Arc-Heated Wind Tunnel Test
Kim, Nam Jo ; Oh, Philyong ; Shin, Eui Sup ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1048~1053
DOI : 10.5139/JKSAS.2015.43.12.1048
Ablative materials in a thermal protection system for atmospheric re-entry suffers from the most severe heat fluxes and temperatures, which induces surface recession in the thickness direction. In this paper, a 0.4MW arc-heated wind tunnel is operated to test for ablative materials, and a non-contact three-dimensional surface measuring system is used to evaluate the different surface characteristics of them. In particular, by postprocessing the three-dimensional image data, the surface roughness and recession of ablative materials can be calculated before and after the wind tunnel test. Moreover, the surface properties are analyzed quantitatively by comparing volume and mass losses of the test specimens.
Flight Technical Error Modeling for UAV supported by Local Area Differential GNSS
Kim, Kiwan ; Kim, Minchan ; Lee, Dong-Kyeong ; Lee, Jiyun ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1054~1061
DOI : 10.5139/JKSAS.2015.43.12.1054
Navigation accuracy, integrity, and safety of commercial Unmanned Aerial Vehicle (UAV) is becoming crucial as utilization of UAV in commercial applications is expected to increase. Recently, the concept of Local-Area Differential GNSS (LADGNSS) which can provide navigation accuracy and integrity of UAV was proposed. LADGNSS can provide differential corrections and separation distances for precise and safe operation of the UAV. In order to derive separation distances between UAVs, modeling of Flight Technical Error (FTE) is required. In most cases, FTE for civil aircraft has been assumed to be zero-mean normal distribution. However, this assumption can cause overconservatism especially for UAV, because UAV may use control and navigation equipments in wider performance range and follow more diverse path than standard airway for civil aircraft. In this research, flight experiments were carried out to understand the characteristics of FTE distribution. Also, this paper proposes to use Johnson distribution which can better describe heavy-tailed and skewed FTE data. Futhermore, Kolmogorov-Smirnov and Anderson-Darling tests were conducted to evaluate the goodness of fit of Johnson model.
Estimation of Moving Target Trajectory using Optimal Smoothing Filter based on Beamforming Data
Jeong, Junho ; Kim, Gyeonghun ; Go, Yeong-Ju ; Lee, Jaehyung ; Kim, Seungkeun ; Choi, Jong-Soo ; Ha, Jae-Hyoun ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1062~1070
DOI : 10.5139/JKSAS.2015.43.12.1062
This paper presents an application of an optimal smoothing filter for moving target tracking problem based on measured noise source. In order to measure distance and velocity for the moving target, a beamforming method is applied to use the noise source by using microphone array. Also a Kalman filter and an optimal smoothing algorithm are adopted to improve accuracy of trajectory estimation by using a Singer target model. The simulation is conducted with a missile dynamics to verify performance of the optimal smoothing filter, and a model rocket is used for experiment environment to compare the trajectory estimation results between the beamforming, the Kalman filter, and the smoother. The Kalman filter results show better tracking performance than the beamforming technique, and the estimation results of the optimal smoother outperform the Kalman filter in terms of trajectory accuracy in the experiment results.
Numerical Study on Thrust Characteristics of an External Pintle Thruster
Choi, Junsub ; Kim, Dongyeon ; Huh, Hwanil ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1071~1078
DOI : 10.5139/JKSAS.2015.43.12.1071
Numerical computations were performed to investigate the effects of pintle stroke, altitude, and bore on the performance of an external pintle thruster. Results show that under-expansion flow occurs always, independent of pintle stroke. An external pintle thruster shows good performance in that it is capable of good amount of thrust control, while aerodynamic loads are increased due to shock waves on the pintle support. When altitude is increased to 20 km, the nozzle exit velocity, Mach number, thrust as well as aerodynamic loads are increased. Bore increases aerodynamic load 5.9%, and therefore pintle shape without bore is preferred for lower aerodynamic load of a pintle in order to actuate the pintle.
Studies of Parallelism and Performance Enhancements of Computing View Factor for Satellite Thermal Analysis
Kim, Min-Ki ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1079~1088
DOI : 10.5139/JKSAS.2015.43.12.1079
Parallelism and performance enhancement of calculating view factors in KSDS developed by KARI is introduced in this paper. View factor is an essential parameters of radiation thermal analysis for a spacecraft, and the amount of computation of them is not negligible. Especially, independent integration of view factors at each position of the orbit because the relative displace between solar panel and main body of a satellite varies with the position on the orbit. This paper introduces a range of parallelism of computing view factor and their performance, detection of obstructions by spatial search algorithm based on KD-Tree, and the reduction of the calculation of view factors of a satellite with relative motion between solar panel and main body, called updating fractional view factor matrix, for satellite thermal analysis.
Stability Test Using Froude Scaling Method of Emergency Flotation System for Helicopter
Chang, In-Ki ; Ryu, Bo-Seong ; Kim, Joung-Hun ; Kim, Young-Jin ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1089~1096
DOI : 10.5139/JKSAS.2015.43.12.1089
A marine helicopter should remain sufficiently upright to permit safe evacuation of all personnel with a flotation system. And the rule requires that after ditching in water, the adequate flotation time will allow the occupants to leave the rotorcraft. To this end, stability test of the emergency flotation system for Korean marine helicopter was performed by using "Froude scaling method" in water tank. Test configuration and conditions were determined in consideration of the helicopter loading condition and related specifications. Test results meet the stability requirements at sea state code 4 and sea state code 2 with puncture conditions.
Feasibility Study of a Series Hybrid-Electric Propulsion System for a Fixed Wing VTOL Unmanned Aerial Vehicle
Kim, Boseong ; Bak, Jeonggyu ; Yun, Senghyun ; Cho, Sooyoung ; Ha, Juhyung ; Park, Gyusung ; Lee, Geunho ; Won, Sunghong ; Moon, Changmo ; Cho, Jinsoo ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1097~1107
DOI : 10.5139/JKSAS.2015.43.12.1097
General VTOL aircraft uses gas turbine engine which has high power to weight ratio. However, in the VTOL UAV in small sector, the gas turbine as a prime mover is not adequate because of the limitation of the high fuel consumption ratio of the gas turbine. In this research, The Series Hybrid-Electric Propulsion System(SHEPS) has been proposed and technology survey & comparison analysis has conducted to constitute propulsion system for engine, electric motor and battery. To achieve this object a 65kg-class P-UAV from "Company I" was used. And to estimate the validity of power control algorithm and developed power management control, Matlab/simulink
has been used for the simulation. As a result, the developed algorithm worked comparatively well and the research has predicted that SHEPS was satisfied enough for 7 hour of endurance for mission profile.
Study on Leakage Measurements of Oxygen and Helium Using Standard Gas Flow Rates in a Orifice Flow
Lee, Joongyoup ; Han, Sangyeop ; Huh, Hwanil ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1108~1115
DOI : 10.5139/JKSAS.2015.43.12.1108
In this study, correlation equations were arranged about mass flow rates of oxygen and volume flow rates of helium using a mouthpiece method. The mouthpiece method can reduce examination cost by using similar empirical formula. Instead of liquid oxygen, in the mouthpiece method, gas helium can be measured in order to determine the leakage amount of liquid oxygen conveniently. Experiment was conducted and compared to understand leakage amount relation between the helium and the oxygen for prototype item under a room and a cryogenic temperature conditions. The leakage volume flow rate [
] of the helium was 174 times higher than mass flow rate [g/s] of the oxygen leakage at liquid state. The derived correlation equations were verified using data from the National Institute of Standards and Technology (NIST).
Statistical Uncertainty Analysis of Thermal Mass Method for Residual Propellant Estimation
Park, Eungsik ; Park, BongKyu ; Huh, Hwanil ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1116~1123
DOI : 10.5139/JKSAS.2015.43.12.1116
The lifetime of a geostationary satellite depends on the residual propellant amount and therefore the precise residual propellant gauging is very important for the mitigation of economic loss arised from premature removal of satellite from its orbit, satellites replacement planning, slot management and so on. In this paper, the thermal mass method and its uncertainty are described. The residual propellant analysis of a geostationary satellite is simulated based on the KOREASAT data and the uncertainty of thermal mass method is calculated by using the Monte Carlo method. The results of this study show the importance parameter of estimation residual propellant using the thermal mass method.
A 5-DOF Ground Testbed for Developing Rendezvous/Docking Algorithm of a Nano-satellite
Choi, Won-Sub ; Cho, Dong-Hyun ; Song, Ha-Ryong ; Kim, Jong-Hak ; Ko, Su-Jeong ; Kim, Hae-Dong ;
Journal of the Korean Society for Aeronautical & Space Sciences, volume 43, issue 12, 2015, Pages 1124~1131
DOI : 10.5139/JKSAS.2015.43.12.1124
This paper describes a 5-dof ground testbed which emulates micro-gravity environment for developing Rendezvous/docking algorithm of a nano-satellite. The testbed consists of two parts, the low part which eliminates friction force with ground and the upper part which has 3-dof rotational motion with respect to the low part. For Vison-based autonomous navigation algorithm, we use camera, LIDAR and AHRS as sensors and eight cold gas thrusters and three axis directional reaction wheels as actuators. All system software are implemented with C++ based on on-board computer and Linux OS.