• 시스템엔지니어링워크숍
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• s.4
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• pp.155-158
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• 2004

In executing the large scale national project, such as development of space launch vehicle, it is most important to guarantee the technological reliability. However the reliability analysis of launch vehicle is different from other mass product goods because of the limitation of budget and number of tests. In this study, the reliability analysis technique of the propulsion system, which is one of the major sub-systems of launch vehicle is illustrated applied to the liquid rocket engine of KSR-Ⅲ.Ȁ

• Advances in aircraft and spacecraft science
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• v.4 no.4
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• pp.437-448
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• 2017

The problem of flow through the vent is formulated as an unsteady, nonlinear, ordinary differential equation and solved using Runge-Kutta method to obtain pressure inside payload faring. An inverse problem for prediction of the discharge coefficient is presented employing measured internal pressure of the payload fairing during the ascent phase of a satellite launch vehicle. A controlled random search method is used to estimate the discharge coefficient from the measured transient pressure history during the ascent period of the launch vehicle. The algorithm predicts the discharge coefficient stepwise with function of Mach number. The estimated values of the discharge coefficients are in good agreement with differential pressure measured during the flight of typical satellite launch vehicle.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1403-1405
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• 2008

In this paper, the preliminary EMC analysis process between the Communication, Ocean and Meteorological Satellite (COMS) and Geostationary Earth Orbit (GEO) launch vehicles in the frequency range [1MHz-47MHz] is described. The considered launch vehicle is the Arian V. The launch vehicle Radiated Emission (RE) specifications have been compared to COMS satellite Radiated Susceptibility (RS) limits. The COMS RS limits are the RS qualification levels of COMS units during launch. As a result, The radiated emission levels of the Arian V is compliant with COMS RS limits.

• Journal of the Korean Society of Systems Engineering
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• v.1 no.1
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• pp.61-66
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• 2005

In executing the large scale national project, such as development of space launch vehicle, it is most important to guarantee the technological reliability. However the reliability analysis of launch vehicle is different from other mass product goods because of the limitation of budget and number of tests. In this study, the reliability analysis technique of the propulsion system, which is one of the major sub-systems of launch vehicle is illustrated and applied to the liquid rocket engine of KSR-III.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.341-343
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• 2004

In executing the large scale national project, such as development of space launch vehicle, it is most important to guarantee the technological reliability. However the reliability analysis of launch vehicle is different from other mass product goods because of the limitation of budget and number of tests. In this study, the reliability analysis technique of the propulsion system, which is one of the major sub-systems of launch vehicle is illustrated and applied to the liquid rocket engine of KSR-III.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.375-378
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• 2010

Hot and high speed plume exhausted during KSLV-I flight test is cooled down by an amount of water ejected from 'gas deflector cooling system' of launch complex to reduce the effects on the launch vehicle and launch complex. In this study, simplified axisymmetric computational calculation with 2-phase is carried out to analysis the water injection effects on flow field.

• Advances in aircraft and spacecraft science
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• v.9 no.3
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• pp.263-278
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• 2022

The time-varying structural reliability of an aeroelastic launch vehicle subjected to stochastic parameters is investigated. The launch vehicle structure is under the combined action of several stochastic loads that include aerodynamics, thrust as well as internal combustion pressure. The launch vehicle's main body structural flexibility is modeled via the normal mode shapes of a free-free Euler beam, where the aerodynamic loadings on the vehicle are due to force on each incremental section of the vehicle. The rigid and elastic coupled nonlinear equations of motion are derived following the Lagrangian approach that results in a complete aeroelastic simulation for the prediction of the instantaneous launch vehicle rigid-body motion as well as the body elastic deformations. Reliability analysis has been performed based on two distinct limit state functions, defined as the maximum launch vehicle tip elastic deformation and also the maximum allowable stress occurring along the launch vehicle total length. In this fashion, the time-dependent reliability problem can be converted into an equivalent time-invariant reliability problem. Subsequently, the first-order reliability method, as well as the Monte Carlo simulation schemes, are employed to determine and verify the aeroelastic launch vehicle dynamic failure probability for a given flight time.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.6
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• pp.75-81
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• 2014

The flame deflector should be constructed to minimize the induced environmental effects on the launch vehicle and to minimize the exhaust impingement effects on the launch complex structures during the lift-off operation. Therefore, it should be designed to avoid recirculation and reverse flow of rocket exhaust plumes. The circumstance around launch complex and characteristics of launch vehicle should be taken into consideration for the flame deflector design. In this paper, we designed the flame deflector reflecting KSLV-II 1st engine characteristics and analyzed the effect of exhaust plumes related to change geometry by means of computational flow analysis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.5-13
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• 2017

To lunch the Korea Space Launch Vehicle-II(KSLV-II), the second launch complex will be constructed on the Naro Space Center and Kerosene Filling System (KFS) will be also installed newly. KFS of KSLV-II launch complex system is being designed based on Naro Launch Complex. But this must supply fuel to fuel tanks of the vehicle with only a supply pump because KSLV-II is a 3-stage launch vehicle unlike Naro Launch Vehicle or Test Launch Vehicle (TLV). A sudden rise of pump output pressure is recognized during fuel filling scenario selection process. This occurs because return flow can not actively deal with a lot of flow change using flow control method of orifice type. To solve this problem, it is verified that fuel can be stably supplied by installation of accumulator and an appropriate adjustment of filling mode change sequence through flow analysis of various cases.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.132-140
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• 2018

To lunch the Korea Space Launch Vehicle-II(KSLV-II), a second launch complex will be built at the Naro Space Center, and a Kerosene Filling System (KFS) will be installed. KFS of KSLV-II launch complex system is being designed based on Naro Launch Complex. But this must supply fuel to fuel tanks of the vehicle with only a supply pump because KSLV-II is a 3-stage launch vehicle unlike Naro Launch Vehicle or Test Launch Vehicle (TLV). A sudden rise of pump output pressure is recognized during fuel filling scenario selection process. This occurs because return flow can not actively deal with much flow change using the orifice-type flow-control method. To solve this problem, it is verified that fuel can be stably supplied by installing an accumulator, designed for appropriate adjustment of filling-mode change sequence via flow analysis of various cases.