scholarly journals Development of Solid Gas Generating Compositions to Ensure Non Explosiveness of Spent Orbital Stages of Liquid Rocket of Space Launch Vehicles

2017 ◽  
Vol 19 (1) ◽  
pp. 63
Author(s):  
V. Trushlyakov ◽  
K. Zharikov ◽  
D. Lempert
Keyword(s):  
Rocket Engine ◽  
Drainage System ◽  
Combustion Products ◽  
Launch Vehicle ◽  
Liquid Oxygen ◽  
Launch Vehicles ◽  
Gas Generator ◽  
Space Launch ◽  
Surrounding Space ◽  
Liquid Rocket

The choice is discussed of solid gas generating compositions for venting by hot combustion products a fuel tank of the spent orbital stage of a space launch vehicle with a main liquid rocket engine. Non explosiveness is achieved via eliminating the<br />possibility of freezing the drainage system when products of gasification (vapours of a propellant component + the remains of a gas boost + the hot products of combustion of solid gas generating compositions) are discharged from the tank into surrounding space. There are imposed requirements, constraints, and criteria for selecting solid gas generating compositions. When considering tank with the residues of liquid oxygen belonging to orbital spent stage of the launch vehicle «Zenith» the ways are shown how to ensure explosion safety, which on the basis of proposed approaches by selecting solid gas generating compositions (SGC) which generate oxygen and<br />nitrogen. As a criterion of choice of SGC the total mass of the gasification system is adopted, which includes the SGC mass for gasification of liquid propellant residues, the mass of the gas generator and the mass of system to supply the combustion products of SGC into the tank. It is proposed use of residual heat in the condensed phase of the SGC combustion products to heat up the drainage system, which will increase the probability of a trouble-free operation of the drainage system.

Fluid Mode Excitation in Launch Vehicle Feed Lines Induced by Pogo Accumulator Venting

2014 ◽  
Author(s):  
Kirk W. Dotson ◽  
Brian H. Sako ◽  
Trinh T. Nguyen
Keyword(s):  
Space Vehicle ◽  
Launch Vehicle ◽  
Liquid Oxygen ◽  
Rocket Engines ◽  
Launch Vehicles ◽  
Feed Line ◽  
Large Pressure ◽  
Structural Responses ◽  
Flow Oscillations ◽  
Liquid Rocket

Launch vehicles with liquid rocket engines have feed lines through which propellants flow to the engine. To prevent feedback between structural responses and propellant pressure and flow oscillations, a compliant device called a pogo accumulator is typically installed in the propellant feed line. Even if a catastrophic interaction is thus averted, the fluid-induced structural responses may exceed those for important flight events such as liftoff and atmospheric buffeting. In that case, the fluid-induced excitation must be predicted in order to ensure adequate structural margins for the launch vehicle and space vehicle hardware. Venting of compliant gas in the pogo accumulator prior to engine shutdown is known to exacerbate the fluid-induced excitation. In particular, for the Atlas V launch vehicle, a 5–7 Hz fluid mode with large pressure gains at the aft end of the liquid oxygen feed line often excites structural modes just prior to engine cutoff. A methodology for the prediction of these structural responses is presented.

System performance tests and start transient analysis of a liquid rocket engine turbopump

2012 ◽  
Vol 227 (3) ◽  
pp. 470-480
Author(s):  
Soon-Sam Hong ◽  
Dae-Jin Kim ◽  
Jin-Sun Kim ◽  
Jinhan Kim
Keyword(s):  
Rocket Engine ◽  
Hydrogen Gas ◽  
Liquid Oxygen ◽  
Test Results ◽  
Gas Generator ◽  
Fuel Pump ◽  
Performance Requirements ◽  
Component Test ◽  
Liquid Rocket ◽  
Model Fluids

This article describes a series of development tests of a turbopump, which can be applied to a gas generator cycle rocket engine with liquid oxygen and kerosene propellants. A turbine drives both an oxidizer pump and a fuel pump in the turbopump assembly. In the tests, liquid oxygen and kerosene are supplied to the oxidizer pump and the fuel pump, respectively, while either cold hydrogen gas or hot gas from the gas generator is supplied to the turbine. The turbopump is operated reliably at both on-design and off-design conditions, meeting all the performance requirements. The test results are compared with those of the turbopump component tests, where model fluids are used, that is, water for the oxidizer pump and the fuel pump, and cold air for the turbine. The turbopump tests results agree well with the turbopump component test results. The speed buildup of the turbopump at start period is calculated when pressurized gas is used to initially spin the turbine. A differential equation which represents the torque balance between the turbine and the pumps is solved. The calculation shows a good agreement with the test result. When the mechanical loss of the turbopump is considered, a better estimation is obtained.

Conceptual study of a dual-rocket-based-combined-cycle powered two-stage-to-orbit launch vehicle

2017 ◽  
Vol 232 (5) ◽  
pp. 944-957 ◽  
Author(s):  
Fan Zhang ◽  
Huiqiang Zhang ◽  
Bing Wang
Keyword(s):  
Rocket Engine ◽  
Launch Vehicle ◽  
Combined Cycle ◽  
Liquid Oxygen ◽  
Liquid Rocket Engine ◽  
Hybrid Mode ◽  
Two Stage ◽  
Payload Mass ◽  
Liquid Rocket ◽  
Load State

The liquid oxygen/methane staged cycle liquid-rocket engine is one of the most potential rocket engines in the future for its higher performance, higher fuel density and reusable capacity. Two working states of this liquid-rocket engine named as full-load state and half-load state are defined in this paper. Based on this liquid-rocket engine, a dual-rocket-based-combined-cycle propulsion system with liquid oxygen /air/methane as propellants is therefore proposed. The dual-rocket-based-combined-cycle system has then five working modes: the hybrid mode, pure ejector mode, ramjet mode, scramjet mode and pure rocket mode. In hybrid mode, the booster and ejector rockets driven by the full-load liquid-rocket engine work together with the purpose of reducing thrust demand on ejector rocket. In scramjet mode, the fuel-rich burned hot gas generated by the half-load liquid-rocket engine is used as fuel, which is helpful to reduce the technical difficulty of scramjet in hypersonic speed. The five working modes of dual-rocket-based-combined-cycle are highly integrated based on the full- or half-load state of the liquid oxygen/methane staged cycle liquid-rocket engine, and the unified single type fuel of liquid methane is adopted for the whole modes. Then a preliminary design of a horizontal takeoff two-stage-to-orbit launch vehicle is conducted based on the dual-rocket-based-combined-cycle propulsion system. Under an averaged baseline thrust and specific impulse, the launch trajectory to reach a low Earth orbit at 100 km is optimized via the pseudo-spectral method subject to maximizing the payload mass. It is shown that the two-stage-to-orbit vehicle based on the dual-rocket-based-combined-cycle can achieve the payload mass fraction of 0.0469 and 0.0576 for polar mission and equatorial mission, respectively. Conclusively, insights gained in this paper can be usefully applied to a more detailed design of the dual-rocket-based-combined-cycle powered two-stage-to-orbit launch vehicle.

Interaction of Liquid Propellant and Coupled System Structure for Atlas V Launch Vehicle

2010 ◽  
Author(s):  
Kirk W. Dotson ◽  
Brian H. Sako ◽  
Daniel R. Morgenthaler
Keyword(s):  
Hydraulic System ◽  
Coupled System ◽  
Launch Vehicle ◽  
System Structure ◽  
Liquid Oxygen ◽  
Launch Vehicles ◽  
Liquid Propellant ◽  
Pressure Oscillations ◽  
Maximum Acceleration ◽  
Structure Interaction

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.

scholarly journals Calculation of Toxic Substance Burning with Formation of Combustion Products’ Vertical Supersonic Stream

2016 ◽  
Vol 5 (6) ◽  
pp. 30-37
Author(s):  
Дорофеев ◽  
A. Dorofeev ◽  
Бурцев ◽  
I. Burtsev
Keyword(s):  
Mathematical Modeling ◽  
Supersonic Flow ◽  
Rocket Engine ◽  
Toxic Substance ◽  
Combustion Products ◽  
Liquid Rocket Engine ◽  
Supersonic Stream ◽  
Gas Dynamic ◽  
Liquid Rocket ◽  
The One

A system for burning of a destroyed highly toxic substance with formation of a vertical supersonic stream of combustion products moved away to the atmosphere on considerable heights has been considered. A technique and an algorithm for conjugated gas-dynamic and thermodynamic calculation of working processes in two-zonal unit with primary burning using air in a camera similar to the one of a liquid rocket engine, and after-burning in a supersonic flow have been proposed. The technique has been approved on the examples of after-burning mathematical modeling and a parametrical research on combustion completeness influence on composition and properties of products resulting from heptyl combustion in air with after-burning in case of methane supply in the second zone.

scholarly journals Energetic Compositions Application for the Reduction of the Environmental Pollution Because of Space Vehicle Launches

2017 ◽  
Vol 19 (3) ◽  
pp. 239 ◽  
Author(s):  
V. Trushlyakov ◽  
D. Lempert ◽  
Yuan-Jie Shu
Keyword(s):  
Rocket Engine ◽  
Space Vehicle ◽  
Combustion Products ◽  
Near Earth Space ◽  
The Earth ◽  
Space Launch ◽  
Energetic Compositions ◽  
Heating Up ◽  
Space Activities ◽  
Total Velocity

Technogeneous impact of rocket and space activities on the environment is one of the most actual problems of practical cosmonautics. This technogeneous impact is not only the pollution of near Earth space with space debris (worked-off stages of space launch vehicle (SLV)), but also the pollution of significant areas on the Earth surface with worked-off lower stages of SLV, which fall down after having accomplished their mission. In OmSTU and IPCP RAS it was suggested to apply different self-burning compositions, generating hot gases for the evaporation of the unused residues of liquid propellant in tanks of SLV. Then the mixture of the evaporated compounds together with the gaseous combustion products from gas-generating compositions is used as propellant mixture for the autonomous gas rocket engine. Such a solution would decrease considerably the level of the environment pollution and additionally it increases the energetic characteristics of SLV. For example, in the case of the second stage of SLV «Soyuz-2.1.v» it increases the total velocity by 5%. Also it is proposed to use firing the pyrotechnic compositions like (thermites) for the fairings heating up to the temperature when the fairing material can be ignited in air. It would reduce considerably the amount and the mass of the separating parts of SLV that fall to the Earth.

scholarly journals Critical Design Result of Liquid Oxygen Filling System for Korea Space Launch Vehicle-II Launch Complex

2017 ◽  
Vol 21 (2) ◽  
pp. 102-110
Author(s):  
Mansu Seo ◽  
Min-Ho Ko ◽  
Jeong-Woon Sun ◽  
Hyun-Min Suh ◽  
Jae Jun Lee ◽  
...  
Keyword(s):  
Launch Vehicle ◽  
Liquid Oxygen ◽  
Critical Design ◽  
Filling System ◽  
Space Launch ◽  
Design Result
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