• Title/Summary/Keyword: trim

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An experimental study on the improvement of resistance performance by appendage for 50 knots class planing hull form (50노트급 활주형선의 저항성능 개선을 위한 부가물 부착에 관한 실험적 연구)

  • Lee, Kwi-Joo;Park, Na-Ra;Lee, Eun-Jung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.3
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    • pp.222-226
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    • 2005
  • A series of model tests carried out at the CWC of WJFEL for the purpose of prediction of resistance for the performance and improvement of resistance by attaching appendage for the ship of 50 knots class planing hull. The resistance performance evaluation has been carried out for the bare hull and for the appendage hull with two different depth of vertical type wedges. In the bare model test, trim and sinkage is calculated for the planing hull and the resistance is calculated. For minimizing the resistance, wedge appendage is attached and tested. Analysis and tests shows that for a 12.5mm wedge, resistance is minimum and overall power tallied to 5636ps.

A Study on an Effect of Seat Wing for Injury Reduction in Case of Side Crash (측면 충돌시 시트윙에 의한 상해치 저감 효과 연구)

  • Lee Hyun-Seop;Huh Yong-jeong
    • Proceedings of the KAIS Fall Conference
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    • 2005.05a
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    • pp.83-85
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    • 2005
  • 본 연구는 측면 충돌 시 발생하는 상해치를 분석하고 측면 충돌 시 시트윙(seat wing)이 운전자 상해에 미치는 영향을 비교 분석하는데 그 목적이 있으며, 이를 효율적으로 수행하기 위하여 모델(door trim)을 단순화하여 원활한 해석이 가능하도록 해석 모델을 구성하였다. 측면 충돌의 경우 운전석의 에어백과 안전 밸트 사이에서 운전자가 도어에 직접적인 충돌에너지를 받으므로 상해치가 정면충돌에 비해 상당히 높아질 수 있다. 측면 충돌 시 시트윙(seat wing)의 장착 유/무에 따른 차이를 더미 (TNO&JARI)모델을 이용한 Madymo 해석을 통하여 상해치 저감효과를 입증하고자 한다.

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Derivation and Verification of the Relative Dynamics Equations for Aerial Refueling (공중재급유를 위한 상대운동방정식 유도 및 검증)

  • Jang, Jieun;Lee, Sangjong;Ryu, Hyuk
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.21 no.4
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    • pp.1-10
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    • 2013
  • This paper addresses the derivation of 6-DOF equation of Tanker and Receiver's aircraft for aerial refueling. The new set of nonlinear equations are derived in terms of the relative translational and rotational motion of receiver aircraft respect to the tanker aircraft body frame. Further the wind effect terms due to the tanker's turbulence are included. The derivation of absolute dynamic equation for tanker aircraft written in the inertial frame is calculated from the relative dynamics equations of receiver. The derived relative and absolute equations are implemented the simulation in the same flight conditions to verify the relative motion and compare the trim results by using the MATLAB/SIMULINK program.

Predictions on the Internal Loads and Structural Deflection in a Full-scale Experimental Bearingless Rotor

  • Eun, WongJong;Ryu, HanYeol;Shin, SangJoon;Kee, YoungJung;Kim, Deog-Kwan
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.1
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    • pp.110-122
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    • 2015
  • In this paper, the unsteady aerodynamics and blade structural dynamics of an experimental bearingless rotor were analyzed. Due to the multiple load path and nonlinear behavior of a bearingless rotor, sophisticated structural modeling and structural-aerodynamic coupled analysis is required. To predict the internal load and deformation of an experimental bearingless rotor, trim analysis was implemented. The results showed good agreement when compared with those predicted by CAMRAD II the rotorcraft comprehensive analysis. It is possible to extend the present structural-aerodynamic combined analysis to further advanced configurations of the bearingless rotor in the future.

Dopant-Activation and Damage-Recovery of Ion-Shower-Doped Poly-Si through $PH_3/H_2$ after Furnace Annealing

  • Kim, Dong-Min;Kim, Dae-Sup;Ro, Jae-Sang;Choi, Kyu-Hwan;Lee, Ki-Yong
    • Journal of Information Display
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    • v.5 no.1
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    • pp.1-6
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    • 2004
  • Ion shower doping with a main ion source of $P_2H_x$ using a source gas mixture of $PH_3/H_2$ was conducted on excimer-laser- annealed (ELA) poly-Si. The crystallinity of the as-implanted samples was measured using a UV-transmittance. The measured value of as-implanted damage was found to correlate well with the one calculated through/obtained from TRIM-code simulation. The sheet resistance was found to decrease as the acceleration voltage increased from 1 kV to 15 kV at a doping time of 1 min. However, it increases as the acceleration voltage increases under severe doping conditions. Uncured damage after furnace annealing is responsible for the rise in sheet resistance.

Synthesis and Characterization of Co-Surfactant Templated Mesoporous Materials with Enhanced Hydrothermal Stability

  • Kim Geon-Joong;Kim Hyun-Seok;Ko Yoon Soo;Kwon Yong Ku
    • Macromolecular Research
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    • v.13 no.6
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    • pp.499-505
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    • 2005
  • Ordered mesoporous materials with a hydrothermally-stable, protozeolitic framework were prepared by exploring the direct conversion of inorganic species based on co-surfactant templating systems. To confer hydrothermal stability on the mesoporous aterials, the organic-inorganic hybrids were heat-treated in strongly basic media. Co-surfactant templating systems of cetyltrimethylammonium bromide [$C_{16}H_{13}(CH_{3})_{3}$NBr, CTAB] with 1,3,5-trim­ethylbenzene (TMB) or a nonionic block copolymer of poly(ethylene oxide )-b-poly(propylene oxide )-b-poly(ethyl­ene oxide) ($EO_{20}PO_{70}EO_{20}$) were employed to improve the hydrothermal stability of the organic-inorganic self-assembly during the solid rearrangement process of the inorganic species. The mesoscopic ordering of the pore structure and geometry was identified by X-ray diffraction, small angle neutron scattering and electron microscopy.

- Development of the multi axis whetstone system in the stone polishing process for the work environment improvement - (작업환경개선을 위한 석재연마공정에 있어서의 다축마석연마장치 개발)

  • Kang Ji Ho;Hong Dong Pyo
    • Journal of the Korea Safety Management & Science
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    • v.6 no.4
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    • pp.171-181
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    • 2004
  • A multi axis whetstone polishing system, which uses the flow system of the stone polishing machine head, has been developed. The test results show that the defect by line contact polishing does not occur in both ends of the stone and that it came to trim smoothly. In terms of the surface roughness, the corresponding index was decreased by 3.6 times, improving the polishing effect greatly. It decreased significantly the dust and noise with the wet polishing. The factors of the duty evasion at production site can thus be solved with the work environment improvement against the polishing process of the stone industry and work intensive reduction.

Panel cutting method: new approach to generate panels on a hull in Rankine source potential approximation

  • Choi, Hee-Jong;Chun, Ho-Hwan;Park, Il-Ryong;Kim, Jin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.3 no.4
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    • pp.225-232
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    • 2011
  • In the present study, a new hull panel generation algorithm, namely panel cutting method, was developed to predict flow phenomena around a ship using the Rankine source potential based panel method, where the iterative method was used to satisfy the nonlinear free surface condition and the trim and sinkage of the ship was taken into account. Numerical computations were performed to investigate the validity of the proposed hull panel generation algorithm for Series 60 ($C_B$=0.60) hull and KRISO container ship (KCS), a container ship designed by Maritime and Ocean Engineering Research Institute (MOERI). The computational results were validated by comparing with the existing experimental data.

Flight Test of Pitch Control Force for an Airplane (항공기 피치 조종력 비행시험)

  • Lee, Jung-hoon
    • Journal of Aerospace System Engineering
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    • v.8 no.3
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    • pp.20-26
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    • 2014
  • This paper presents the procedures and the results of the pitch control force via flight test for a light airplane in order to make out the stability of the aircraft and the compliance with concerned regulation. The flight test procedures were determined in order to obtain the aircraft type certification. The instrumentation equipments including airspeed indicator, accelerometer, and pitch control force measurement tools are used to perform the flight test. For the flight test, the airspeed and the pitch control force with related normal acceleration are measured sustaining turn flight with bank angle derived from trim speed. The flight test results showed that the handling qualities of the airplane are complied with the KAS-23, the regulation of the Korean government for the light airplane type certification.