• Title/Summary/Keyword: 낙하산

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An experimental study on reefing effect on aerodynamics characteristics of cruciform parachute (십자형 낙하산의 Reefing 효과에 따른 공력특성에 관한 실험연구)

  • Lee, Chang-Gu;Kim, Beom-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.7
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    • pp.628-633
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    • 2008
  • Cruciform parachute has advantage in manufacture and expanse compare with circular parachute. But it has disadvantage in stability. Wind tunnel test were conducted to investigate the effects of reefing-line on the cruciform parachutes with the purpose of finding aerodynamics characteristics of the parachute such as drag coefficient, normal force coefficient. Aerodynamics characteristics are measured accurately with 6-components pyramidal balance and load cells which were installed in the fixed-body. Four different models were tested and the test results were compared with each other. The aerodynamics characteristics were changed with reefing-line length. Separation edge was developed due to reefing-line also it made increasing of the stability. The cruciform parachute which improve stability is supposed to be used in variety purpose.

A Wind Tunnel Test for Directional Control of Cruciform Parachutes (십자형 낙하산의 방향 제어에 관한 풍동시험 연구)

  • 임주창;김범수
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.9
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    • pp.20-24
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    • 2006
  • Wind tunnel tests were conducted to compare gliding and turning performance of normal cruciform parachutes with newly modified cruciform parachutes. Modified cruciform parachute has better gliding performance than original cruciform parachutes but, modified cruciform parachute has worse turning performance than original cruciform parachute.

9-DOF Modeling and Turning Flight Simulation Evaluation for Parachute (9-DOF 낙하산 모델링 및 선회비행 시뮬레이션 검증)

  • Lee, Sang-Jong;Min, Byoung-Mun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.688-693
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    • 2016
  • This paper describes the parachute dynamics modeling and simulation results for the development of training simulator of a HALO (High Altitude Low Opening) parachute, which is currently in use for military purposes. The target parachute is a rectangular shaped parafoil and its dynamic model is derived based on the real geometry data as the 9-DOF nonlinear equations of dynamics. The simulation was conducted through the moment of inertia and its aerodynamic derivatives to reflect the real characteristics based on the MATLAB/Simulink. In particular, its modeling includes the typical characteristics of the added mass and moment of inertia, which is shown in the strong effects in Lighter-Than-Air(LTA) flight vehicle. The proposed dynamic modeling was evaluated through the simulation under the spiral turning flight conditions of the asymmetric control inputs and compared with the performance index in the target parachute manual.

An Experimental Study on the Inflation Characteristics of Parachute Canopies (낙하산 캐노피 전개특성에 관한 실험적 연구)

  • Oh, Se-Yoon;Kim, Chan-Ki;Lee, Jong-Geon;Ahn, Seung-Ki
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.30 no.7
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    • pp.11-19
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    • 2002
  • Inflating characteristics of the parachute canopies have been experimentally investigated with the objective of measuring the parachute opening parameters such as canopy filling time and the peak opening force using scaled parachute models. A device has been made and tested to eject a model parachute into a wind tunnel flow and to measure the drag force acting on it. The force-time histories and the peak opening force are obtained, and these comparative aerodynamic characteristics were analyzed and discussed, including the effect of forebody wake. The opening of the ringslot parachute model appeared to be faster than that of the available similar data by about 10~40%, and fair to good agreement was obtained for the reefed ribbon parachute.

Deploy Position Determination for Accurate Parachute Landing of a UAV (무인기의 정밀 낙하산 착륙을 위한 전개지점 결정)

  • Kim, Inhan;Park, Sanghyuk;Park, Woosung;Ryoo, Chang-Kyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.6
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    • pp.465-472
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    • 2013
  • In this paper, we suggest how to determine the parachute deploy position for accurate landing of a UAV at a desired position. The 9-DOF dynamic modeling of UAV-parachute system is required to construct the proposed algorithm based on neural network nonlinear function approximation technique. The input and output data sets to train the neural network are obtained from simulation results using UAV-parachute 9-DOF model. The input data consist of the deploy position, UAV's velocity, and wind velocity. The output data consist of the cross range and down range of landing positions. So we predict the relative landing position from the current UAV position. The deploy position is then determined through distance compensations for the relative landing positions from the desired landing position. The deploy position is consistently calculated and updated.

Effects of Time-Varying Mass on the Dynamic Behavior of a Descending Parachute System (질량 감소가 낙하산 시스템의 하강 고도 변화에 미치는 효과)

  • Jang, Woo-Young;Baek, Sang-Tae;Myong, Rho-Shin;Jin, Yeon-Tae
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.4
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    • pp.281-289
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    • 2016
  • Accurate prediction of the trajectory and time of a time-varying mass parachute system remains essential in the mission requiring a precision airdrop to the ground. In this study, we investigate the altitude-varying behavior of a cross-type parachute system designed to deliver a time-varying mass object like flare. The dynamics of the descending parachute system was analyzed based on the Runge-Kutta method of the ordinary differential system. The drag coefficients of the cross-type parachute and flare were calculated by a CFD code based on the incompressible Navier-Stokes equation. Finally, by using a simplified gust wind model in troposphere, the combined effects of gust wind and time-varying mass were examined in detail.

The Changes of Social Distance, Disability Awareness, and Activity Satisfaction of Occupational Therapy Students through the Parachute Play (낙하산 놀이에 따른 작업치료과 학생들의 성인 지적장애인에 대한 사회적 거리감, 장애인식, 활동 만족도의 변화)

  • Kim, Su-Hyeon;Son, Sung-Min
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.3
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    • pp.393-402
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    • 2020
  • The purpose is to provide the basic information about the changes of the social distance, disability awareness, and activity satisfaction of the occupational therapy students through the parachute play. The subjects were 10 students in the third grade of the occupational therapy. They participated in the parachute play for 4 weeks. Their social distance, disability awareness and activity satisfaction were evaluated. The results showed the changes that the social distance was decreased, disability awareness and the activity satisfaction was increased after the play. Thus, to form the positive social distance and disability awareness and increase the activity satisfaction, the parachute play should be provided for the occupational therapy students.

An Experimental Study of Reefing Effect on Decelerating Parachutes (감속 낙하산 Reefing 효과에 관한 실험적 연구)

  • O, Se-Yun;Kim, Chan-Gi;Park, Geum-Ryong;Hyeon, Jae-Su
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.30 no.2
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    • pp.39-45
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    • 2002
  • The effect of reefing-line length and reefing methods on drag and inflated shape of the conical ribbon parachute were experimentally investigated. Tests were performed to determine reefing-line length of the parachute models, demonstrate aerodynamic adequacy of the reefing method, and confirmed that performance met the design requirement. The reefing ratio, drag-area ratio, was decreased in relation to the decrease in the length of the reefing-line and the stability of the parachute models was increased with reefing. The test results were compared with the avilable similar data. Fair to good agreement was obtained.

A study on the developmental method of parachute and air stabilizer for light weight torpedo (경어뢰용 낙하산 조립체 개발 방법에 관한 연구)

  • 신용재
    • Journal of the Korea Institute of Military Science and Technology
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    • v.4 no.1
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    • pp.137-146
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    • 2001
  • According to the advanced development of Light Weight Torpedo, the overall items related with the parachute type and gore layout and air stabilizer of the parachute for fixed and rotary wing aircraft are described in this paper. Also, the drag-area which should satisfy the firing envelope, parachute inflation characteristics, stability of parachute and torpedo in airdropping, water entry impact on torpedo and parachute constituted the principle design factors. The important trial and errors occurred in the step of performance of the parachute for fixed and rotary wing aircraft are investigated and analyzed.

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Design for Spin/Stall Recovery Parachute System of Turbo-prop Airplane (터보프롭 항공기의 스핀/실속 회복장치 설계)

  • Lee, Dong-Hun;Nho, Byung-Chan;Kang, Myung-Kag;Kang, Gyeong-Woo;Lee, Ju-Ha
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.8
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    • pp.726-736
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    • 2012
  • This paper deals with Spin/Stall Recovery Parachute System from design to ground taxiing stage which would be deployed on the high speed taxi of turbo-prop airplane. In detail design phase, design parameters- riser length, parachute type, size, porosity, parachute canopy filling time, and deployment method- were considered based on the analytical disciplines such as aerodynamics, structures, and stability & control. Before the installation of Spin/Stall Recovery System of turbo-prop airplane, all control functions of this system were validated by the SBTB(System Breakout Test Box) in the laboratory. SBTB was used to confirm if it can detect faults, and simulate the firing of pyrotechnic devices that control the deployment and jettison of it. Once confirmed normal operation, deployment of parachute on the high speed taxiing were performed.