• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.11a
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• pp.21-21
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• 1997

인공위성용 추진제 탱크를 개발하기 위해 여러 설계인자를 설정하여 각 인자가 탱크벽면에 미치는 응력분포 영향을 구하고, 또한 최적의 인자 값을 구하기 위해 각 인자의 변화에 따라서 구조해석을 수행하였다. 탱크 지지부 위치와 탱크 벽면 두께 변화에 따른 탱크 벽면에 미치는 응력분포 영향을 고찰하기 위해 1/4 모델을 설정하였고, 연료배출구의 위치변화(경사각돈)에 따른 응력분포는 1/2 모델을 설정하여 해석을 하였다. 탱크에 작용하는 하중은 연료압력에 의해 발생하는 정하중(350 psi)을 가하며 또한, 발사 시 발사체로부터 전달되는 최대동하중(llg)을 고려하였다. 그리고, 탱크가 인공위성에 장착될 때에 발생하는 다양한 장착조건에 대해서 구조해석을 수행하였고, 추진제 배출구 각도가 $0^{\circ}$ 에서 $25^{\circ}C$까지 변화할 때 탱크 벽면에 미치는 응력분포 영향을 구했다. 그래서 각 조건에서 구한 상당응력분포와 인자의 최적 값은 추진제 탱크를 설계하기 위한 기초적인 자료로 활용하고자 한다.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.5
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• pp.89-95
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• 2011

Korea Space Launch Vehicle II (KSLV-II) planned to launch in 2021 is 3 stage rocket which can inject 1.5 ton satellite in low earth orbit. KSLV-II will adapt the newly developed liquid rocket engines for its propulsion system of each stage. For the evaluation of development level for rocket engine, integrated system test performed in appropriate facility is needed. In this study, test article and major parameters for certifying the propulsion system of KSLV-II were reviewed and optimum test cycle and test duration for satisfying system reliability requirement were illustrated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.488-494
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• 2014

Rocket Plumes can cause serious damage to launch vehicles and adjacent structures. This paper describes the impact of an adjacent structure by a rocket plume. Each parameter related with dynamic behavior of a missile is modeled with probabilistic distributions of variables. Flyout analyses of initial behavior of a vertically launched missile are performed using Monte-Carlo simulation and flow-motion analyses were conducted by using CFD. In this way, when a missile is fired by a ship, the impact of an adjacent structure by a rocket plume was analyzed.

• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.65-73
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• 2011

After launch, in order to inject the geostationary satellite into its operational orbit, the perigee altitude are forced to be raised to geostationary altitude by firing onboard LAE(Liquid Apogee Engine) at apogee of the transfer orbit. In this process, the LAE burn is divided into three or four separated burns in order to control the orbit very precisely by giving feedback the determined orbit informations and to inject the satellite in predefined longitude. This paper proposes an algorithm to determine LAE firing time slots and ${\Delta}V$ vectors under assumption of impulsive LAE burning, and additionally, a method to compensate errors induced by continuous burning. And computer simulations have been performed to validate proposed algorithms.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.3
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• pp.71-80
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• 2020

Before we develop LVAFoam, a CFD software for launch vehicle analysis, we conducted a survey on other CFD softwares. We looked at in-house code and commercial CFD software of other countries that were used as a simulation of launch vehicle's combustor, turbopump and external flow. This research included in-house code solvers, developed by NASA, Mississippi State University, DLR, Bertin Technologies, CNES, CERFACS, and JAXA as well as commercial CFD software from FLUENT, CFX, Advance/FrontFlow/red, GASP, CRUNCH CFD, CFD-ACE+, FINE^TM/Turbo, STAR-CCM+. The simulation cases of launch vehicle analysis from each commercial softwares and introduction of the LVAFoam were presented.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.5
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• pp.39-49
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• 2017

A Space Launch Vehicle (SLV) for Launching Satellites Consists of Multi-stage Rockets for the Purpose of Efficient Flight and Accomplishes the Launch Mission through Flight Events such as Stage Separation, Engine Start and Stop. In this Process, the SLV is Supposed to Undergo the Processes of the Powered Flight Section in which the Engine Generates Thrust and the Ballistic Flight Section in which there is no Thrust Repeatedly. Because it is Difficult to Express these Flight Characteristics of the SLV as a Single Dynamics Model, much Research on Tracking Algorithms using Multiple Models has been Undertaken. In case of using the Multiple Model Tracking Algorithm, it is Expected to Improve the Tracking Performance of the SLV. However, it is Difficult to Select Proper Dynamics Models to be used and the Calculation Amount Increases due to the use of Multiple Models. In this Paper, we Propose a Method to Track the SLV with Diverse Flight Characteristics Efficiently by only Two Kalman Filters using Constant Acceleration Model and Adaptive Singer Model.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.91-97
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• 2017

The KSLV-II launch complex system consists of mechanical ground support equipment(MGSE), fuel ground support equipment(FGSE), electrical ground support equipment(EGSE) and infrastructures. Compressed gas supply system, as a part of FGSE, is responsible for launch operations such as gas intake, storage, supply to launch vehicle and ground support equipments. This system consists of three primary elements such as gas storage part, control panel and controller. Automatic panels, as a part of control panel, are manufactured to operate remotely by controller. This study presents compressed gas supply system which is designed for KSLV-II and ground support equipment characteristics.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.185-191
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• 2019

During the modern battlefields of multi-batches flight formation attack situation, it is an essential task for a commander to make a proper fire distribution of air defense missile launch platforms for threat targets with effectively and quickly. Pan et al. try to solve this problem using genetic algorithm, but they are fails. This paper gets the initial feasible solution using high threat target first destroying strategy only use 75% available fire of each missile launch platform. Then, the assigned missile is moving to another target in the case of decreasing total threat. As a result of experiment, while the proposed algorithm is polynomial-time complexity greedy algorithm but this can be improve the solution than genetic algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.11
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• pp.914-921
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• 2017

The experimental research on a high-altitude environment simulation of space launch vehicle is important for securing independent technologies with launching space vehicles and completing missions. This study selected an altitude of 65 km for the experiment environment where it exceeded Mach number of 6 after the launch of Korean Space Launch Vehicle(KSLV-II). Shock tunnel was used to replicate the flight condition. After flow establishment, in order to confirm aerodynamic characteristics and normal and oblique shockwaves, the flow verification was carried out by measuring stagnation pressure and heat flux of a forebody model, and shockwave stand-off distance of a hemispherical model. In addition, a shock-free technique to recover free-stream condition has been developed and verified. From the results of the three verification tests, it was confirmed that the flow was replicated with the error of about ${\pm}3%$. The error between the slope angle of inclined shockwave of the scaled down transition section model using the shock-free shape and the slope angle of the horizontal plate model, and between the theoretical and the experimental value of the static pressure of the model were confirmed to be 2% and 1%, respectively. As a result, the efficiency of the shockwave cancellation technique has been verified.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.98-99
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• 2003

2005년 국산 소형위성 발사체에 탑재되어 발사 될 예정으로, 과학기술위성2호의 개발이 2002년 10월부터 시작되었다. 과학기술위성2호는 약 100kg의 소형위성으로, 경사각 60～80$^{\circ}$의 300km x 1500km 타원궤도에 발사될 것으로 예상되고 있으며, 라만-a태양촬영망원경(LIST, Larman-a Imaging Solar Telescope)과 레이저정밀거리측정용 반사경이 각각 주 및 부 탑재체로 탑재될 예정이다. 위성레이저정밀거리측정(SLR, Satellite Laser Ranging)이란 위성간의 거리를 가장 정확하게 측정할수 있는 축지학적 기술이다. (중략)