• Title/Summary/Keyword: Launch Vibration

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Shock Separation Test of KOMPSAT-II (다목적 실용위성 2호 충격 분리 시험)

  • 우성현;김홍배;문상무;김영기;김규선
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.1000-1005
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    • 2003
  • The shock separation test simulates the environmental effects of the spacecraft separation from launch vehicle. The shock separation test for a structural model of KOMPSAT-Ⅱ(Korea Multi-Purpose SATellite Ⅱ) was performed in SITC(Satellite Integration & Test Center) launch environmental test hall at KARI(Korea Aerospace Research Institute) to verify the shock test requirement of the spacecraft, to predict the induced acceleration responses on the primary structures and payloads by the explosion of pyre-lock and to perform mechanical fit check. The spacecraft with S/A was mated vertically to LV(Launch Vehicle) adapter simulator via a clamp band, then hoisted and suspended above a foam test bed by four isolation springs secured to the spacecraft hoist fittings to isolate the payload platform shock wave from the sling elements. For separation process, real pyre-devices were used and the time response signals from 60 accelerometers installed on the interested points was acquired and recorded. The SRS responses for each response channels were calculated and the achieved SRS's on the separation plane was reviewed and evaluated in comparison to the ICD(Interface Control Document) value.

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LAUNCH ENVIRONMENTAL TEST FOR KITSAT-3 FM (우리별 3호 비행모델에 대한 발사환경시험)

  • 이상현;장영순;배정석;이동우;정연황;성단근
    • Journal of Astronomy and Space Sciences
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    • v.16 no.1
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    • pp.79-88
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    • 1999
  • The satellite experiences the severe launch environment such as vibration, acceleration, shock, and acoustics induced by rocket. Therefore, the satellite should be designed and manufactured to endure such severe launch environments. In this paper, we describe the structure of the KITSAT-3 FM(Flight Model) and the processes and results of the launch environmental test to ensure the reliability during launch period.

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Acoustic Loads Test of the Upper Stage of KSLV-I (소형위성발사체 상단부의 음향하중시험)

  • Chun, Young-Doo;Park, Jong-Chan;Chung, Eui-Seung;Park, Jung-Joo;Cho, Kwang-Rae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.224-227
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    • 2007
  • This paper introduces the results of acoustic loads test conducted on the upper stage assembly of KSLV-I, which is the first Korea space launch vehicle. A launch vehicle and its payloads are subjected to severe acoustic pressure loading when they lift off and ascent during the transonic periods. Acoustic loadings are spreaded out broad frequncy-spectrum up to 10,000Hz. Acoustic loads are a primary source of structural random vibration of the upper stage and payloads. Therefore, in order to verify the structural integrity of the upper stage assembly of KSLV-I and the survivability of its components under severe random vibration environment, acoustic loads test is conducted in the high intensity acoustic chamber with 142dB (overall SPL). The results show the structural design and component random vibration specifications well meet with the environmental requirements.

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A Bootstrap Method for Analysis of Noise & Vibration Spectrum (부트스트랩 기법을 이용한 소음진동 스펙트럼 분석법 소개)

  • Chun, Young-Doo;Park, Jong-Chan;Chung, Eui-Seung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.185-188
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    • 2008
  • This paper introduces the Bootstrap method for statistical analysis of noise and vibration spectrum in aeronautic and space fields. Generally, all components of a launch vehicle and its payloads are subjected to high intensive noise and vibration environment during the lift-off phase and the ascent phase through Mach =1 and Max Q. In order to verify their survivabilities against these severe vibroacoustic environments during qualification tests and acceptance tests, it is most important to estimate the proper upper limits of the environmental condition. Although NASA has typically utilized the Normal Tolerance Limit method in deriving these levels, the reference[1] says that the Bootstrap can be also an alternative method to estimate the maximum expected environments. In this paper, a general procedure of the Bootstrap method is summarized, and it is applied to analyze acceleration power spectral density functions, which were measured during acoustic test on the upper stage of KSLV-I.

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The Cooling Characteristics of a Gas Deflector Using Water Spray Cooling System in Launch Pad (물 분사 냉각시스템을 이용한 발사대 화염유도로의 냉각특성)

  • Lee, Kwang-Jin;Chung, Yong-Gahp;Cho, Nam-Kyung;Nam, Jung-Won;Jung, Il-Hyung;Ra, Seung-Ho
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.756-762
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    • 2011
  • A gas deflector cooling system plays an important role in the suppression of shock wave generated during the ignition of a launch vehicle engine. Also, this system decrease a large vibration of damaging the payload and structure of the launch vehicle. The gas deflector cooling system in the launch pad of NARO space center was constructed to directly inject water into the plume of the launch vehicle engine. The flight test result of NARO space launch vehicle showed that this method had a good performance on the viewpoint of cooling the gas deflector.

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Acoustic Load Reduction in the Payload of Small Launch Vehicle by using Resonators (공명기를 이용한 소형위성발사체 탑재부의 음향하중 저감)

  • Seo, Sang-Hyeon;Jeong, Ho-Kyeong;Park, Soon-Hong;Jang, Young-Soon;Yi, Yeong-Moo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.234-237
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    • 2007
  • To protect a satellite and electronic equipment from the acoustic load generated by rocket propulsion system, many launch vehicle use acoustic blanket. Acoustic load is main source of random vibration working on the payload. Most high frequency region of the acoustic loads is reduced by payload fairing skins and acoustic blanket, but low frequency region is not. In order to reduce acoustic load of low frequency region, we designed array resonator panel which was made of composite materials. Insertion loss capacity of the payload fairing with acoustic blanket was verified from PLF acoustic test in the acoustic chamber.

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Launch Environment Specification for KOMPSAT-2 (다목적위성 아리랑 2호 발사환경 규격설정)

  • Kim, Hong-Bae;Rhee, Joo-Hun;Kim, Sung-Hoon;Lee, Sang-Seol
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.165-169
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    • 2000
  • High level vibrationional environments induced while launching of spacecraft can damage sensitive equipment or payloads, unless the equipment is properly designed. This is a critical issue for KOMPSAT-2 which will carry a high resolution electro-optic camera and a sophisticated attitude and orbit control system. Thus careful consideration on the launch environment is required in the design stage of spacecraft. This requires generation of vibration specification for each component. This paper describes the generation process of vibrational specification for KOMPAT-2, which is designed and tested by Korean engineers.

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Design Consideration and Verification on Random Vibration of Satellite Electronic Equipment while Launching (발사시 야기되는 랜덤진동을 고려한 위성체 전장품 설계 및 검증에 대한 연구)

  • 김홍배;서현석
    • Journal of KSNVE
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    • v.10 no.6
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    • pp.971-976
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    • 2000
  • High level random vibration environments induced while launching of spacecraft can damage sensitive electronic equipment, unless the equipment is properly packaged. Thus careful consideration on the launch environment, especially for high level random vibration, is required in the design stage of electronic equipment of spacecraft. This paper describes the development process of Solar Array Regulator for KOMPAT-2, which is designed and tested by Korean engineers. Both analytical and experimental techniques are introduced in this paper.

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Proposal of Pipe Pressure Mode Analysis Method in Propulsion System for Predicting the Pogo of Space Launch Vehicle (우주 발사체의 포고현상 예측을 위한 공급/추진계의 파이프 압력모드 해석 기법 제안)

  • Lee, SangGu;Lee, SiHun;Shin, SangJoon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.714-717
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    • 2017
  • Among the factors considered in the design stage of a space launch vehicle using liquid propellant, research has been focused out on the pogo phenomenon, longitudinal dynamic instability. The pogo phenomenon refers to the instability that the longitudinal vibration of the launch vehicle structure causes a change in the pressure and flow rate of the fluids in propulsion system, and this change re-excites the fuselage structure. This mechanism constitutes a closed system to gradually increase the vibration of the launch vehicle. This paper specifically focuses on the dynamic analysis of pressure and flow changes in the propulsion system. Based on the example study of the space shuttle, the acoustic modal analysis of the propulsion system is performed to predict the modes of the supply line causing instability of the fuselage.

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