Design and simulation of hydraulic system for launch vehicle holding device

In structural modeling of launch vehicles, liquid propellant is sometimes rigidly attached to feedline walls. This assumption precludes the interaction of structural modes with propellant pressure and flow. An analysis of fluid-structure interaction (FSI) for the Atlas V launch vehicle revealed that structural models with rigidly-attached propellant yield unconservative response predictions under some conditions. In particular, during the maximum acceleration time of flight, pressure oscillations acting at bends in the Atlas V liquid oxygen (LO2) feedline excite 15–20 Hz structural modes that have considerable gain on the feedline and at the spacecraft interface. The investigation also revealed that the venting of gas from the pogo accumulator is an excitation source and changes the dynamic characteristics of the hydraulic system. The FSI simulation produced during the investigation can be adapted to mission-specific conditions, such that responses and loads are conservatively predicted for any Atlas V flight.

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Extended NGM (1,1,K) Model and its Application to Spectral Prediction of Military Launch Vehicle Hydraulic System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.454.90 ◽

2013 ◽

Vol 454 ◽

pp. 90-93 ◽

Cited By ~ 2

Author(s):

Hai Tao Wang ◽

Lie Hang Gong ◽

Wei Zhao ◽

Hong Fei Zhao

Keyword(s):

Hydraulic System ◽

Launch Vehicle ◽

Forecasting Model ◽

Prediction Formula ◽

Spectrum Prediction ◽

Forecasting Accuracy ◽

Grey Forecasting ◽

Result Show ◽

White Type ◽

Working Status

The extended NGM (1,1,K) grey forecasting model had the defined type and white type mismatching problem. It proposed the extended NGM (1,1,K) model to eliminate the inherent bias caused by mismatch, the model also had given the prediction formula. Compared to the GM (1,1) model, the extended NGM (1,1,K) model had higher fitting and forecasting accuracy. The model was applied to spectrum prediction of Fe concentration of the oil in a certain type of military launch vehicle hydraulic system, it could determine the working status of the hydraulic system effectively combined with Fe concentration thresholds, the result show that the model is effective.

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Analytical Study on Dynamic Characteristics of Hydraulic Cylinder Applied to the Vehicle Holding Device for Launch Vehicle

Journal of the Korean Society of Propulsion Engineers ◽

10.6108/kspe.2017.21.1.044 ◽

2017 ◽

Vol 21 (1) ◽

pp. 44-50

Author(s):

Jaejun Lee ◽

Sangmin Park ◽

Seongpil Yang ◽

Daerae Kim

Keyword(s):

Dynamic Characteristics ◽

Analytical Study ◽

Hydraulic Cylinder ◽

Launch Vehicle ◽

Holding Device

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Study on Improving the Sealing Reliability of Fluid Connector

Journal of Physics Conference Series ◽

10.1088/1742-6596/2125/1/012070 ◽

2021 ◽

Vol 2125 (1) ◽

pp. 012070

Author(s):

Jing Qiao ◽

Guangzai Jin ◽

Guanghui Li ◽

Yu Wang ◽

Xiangling Wang

Keyword(s):

Hydraulic System ◽

Launch Vehicle ◽

The State ◽

Factors Affecting ◽

Oil Leakage ◽

Spring Force ◽

Sealing Ring ◽

Air Intake

Abstract Aiming at the problem of sealing reliability of fluid connector products commonly used in hydraulic system, this paper studies the static seal and the sliding seal. The factors affecting the sealing such as spring force, sealing ring and life of spring are considered one by one and the sealing effect is teseted. The results showed that improved fluid connector can ensure that the hydraulic system is in the state of not even air intake or oil leakage while connecting and disconnecting at any time. The connector has been successfully applied to a certain model of launch vehicle.

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