Finite Amplitude Nonlinear Waves in Liquid Rocket Combustion Chambers

2008 ◽  
Author(s):  
Gary Flandro ◽  
Eric Jacob
Keyword(s):  
Nonlinear Waves ◽  
Finite Amplitude ◽  
Combustion Chambers ◽  
Liquid Rocket

Advanced Composite Materials for Current and Future Propulsion and Industrial Applications

2006 ◽  
Vol 50 ◽  
pp. 174-181 ◽  
Author(s):  
Steffen Beyer ◽  
Stephan Schmidt ◽  
Franz Maidl ◽  
Rolf Meistring ◽  
Marc Bouchez ◽  
...  
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Chemical Vapour ◽  
Liquid Silicon ◽  
Large Temperature ◽  
Rocket Engines ◽  
Combustion Chambers ◽  
Standard Material ◽  
Liquid Rocket ◽  
Engine Components

Various technology programmes in Europe are concerned with preparing for future propulsion technologies to reduce the costs and increase the life time of components for liquid rocket engine components. One of the key roles to fulfil the future requirements and for realizing reusable and robust engine components is the use of modern and innovative materials. One of the key technologies which concern various engine manufacturers worldwide is the development of fibrereinforced ceramics – CMC's (Ceramic Matrix Composites). The advantages for the developers are obvious – the low specific weight, the high specific strength over a large temperature range, and their good damage tolerance compared to monolithic ceramics make this material class extremely interesting as a construction material. Different kind of composite materials are available and produced by EADS ST, the standard material SICARBON® (C/SiC made by Liquid Polymer Infiltration) and the new developed and qualified composite materials SICTEX® (C/SiC made by Liquid Silicon Infiltration) and CARBOTEX® (C/C made by Rapid Chemical Vapour Infiltration). The composites are based on textile techniques like weaving, braiding, stiching and sewing to produce multiaxial preforms, the SICTEX® material is densificated by the cost effective Liquid Silicon Infiltration (LSI). Over the past years, EADS Space Transportation (formerly DASA) has, together with various partners, worked intensively on developing components for airbreathing and liquid rocket engines. Since this, various prototype developments and hot firing-tests with nozzle extensions for upper and core stage engines and combustion chambers of satellite engines were conducted. MBDA France and EADS-ST have been working on the development of fuel-cooled composite structures like combustion chambers and nozzle extensions for future propulsion applications.

Long nonlinear waves in stratified shear flows

1980 ◽  
Vol 101 (2) ◽  
pp. 321-348 ◽  
Author(s):  
S. A. Maslowe ◽  
L. G. Redekopp
Keyword(s):  
Evolution Equation ◽  
Shear Layer ◽  
Nonlinear Waves ◽  
Richardson Number ◽  
Phase Speed ◽  
Radiation Condition ◽  
Finite Amplitude ◽  
Amplitude Equation ◽  
Layer Model ◽  
Damping Term

The propagation of finite-amplitude internal waves in a shear flow is considered for wavelengths that are long compared to the shear-layer thickness. Both singular and regular modes are investigated, and the equation governing the amplitude evolution is derived. The theory is generalized to allow for a radiation condition when the region outside the stratified shear layer is unbounded and weakly stratified. In this case, the evolution equation contains a damping term describing energy loss by radiation which can be used to estimate the persistence of solitary waves or nonlinear wave packets in realistic environments. A continuous three-layer model is studied in detail and closed-form expressions are obtained for the phase speed and the coefficients of the nonlinear and dispersive terms in the amplitude equation as a function of Richardson number.

Study of Hydraulic Characteristics of the Cooling Path of a Model Liquid Rocket Engine Manufactured using Additive Technology of Selective Laser Melting

2019 ◽  
pp. 41-52
Author(s):  
D.A. Yagodnikov ◽  
V.P. Aleksandrenkov ◽  
K.E. Kovalev ◽  
A.G. Grigoryants ◽  
A.A. Drenin
Keyword(s):  
Selective Laser Melting ◽  
Rocket Engine ◽  
Rocket Engines ◽  
Hydraulic Characteristics ◽  
Combustion Chambers ◽  
Laser Melting ◽  
Melting Technology ◽  
Model Liquid ◽  
Cooling Path ◽  
Liquid Rocket

The article discusses hydraulic tests of a model combustion chamber of a liquid-propellant rocket engine with a cooling path made using additive selective laser melting technology. The values of the coefficient of hydraulic resistance in the range of Re = 10--2500 are obtained and the influence of the design features of the cooling tract and its manufacturing technology on the hydraulic characteristics is determined. The results of the performed hydraulic tests confirm the possibility of using additive technologies based on selective laser melting technology for the manufacture of fire and power walls of combustion chambers of liquid rocket engines.

The choice of the composition of the metal transition for the combustion chamber of low-thrust liquid thruster

2018 ◽  
pp. 149-155
Author(s):  
A. S. Razina ◽  
N. P. Astasheva
Keyword(s):  
Composite Material ◽  
Ceramic Composite ◽  
Linear Expansion ◽  
Rocket Engine ◽  
Liquid Rocket Engine ◽  
Low Thrust ◽  
Combustion Chambers ◽  
Metal Combustion ◽  
Liquid Rocket ◽  
Carbon Ceramic

When replacing the metal combustion chambers of a low-thrust liquid rocket engine to combustion chambers made of carbon-ceramic composite material, a problem arises between the connection of metal and carbon-ceramic. To solve this problem, in this work presents the results of strength calculations of the connection of various materials in the form of a transition ring. Replacement of the material will avoid the effect of thermal coefficients of linear expansion on the operation of a low-trust liquid rocket engine to maintain the tightness of the joint node when exposed to operating temperatures.  

Technology for fi nishing combined processing of mineral-ceramic coatings

2020 ◽  
pp. 318-323
Author(s):  
E.V. Panichev ◽  
V.P. Smolentsev ◽  
V.V. Ivanov
Keyword(s):  
Surface Layer ◽  
Protective Coatings ◽  
Combustion Products ◽  
Ceramic Coatings ◽  
Fuel Combustion ◽  
Rocket Engines ◽  
Combustion Chambers ◽  
Temperature Combustion ◽  
Liquid Rocket ◽  
Processing Zone

Technological methods for manufacturing of cooling elements of modern rocket engines are considered, they are developed taking into account the possibility of reusable use. Significant increase in the thermal load on the walls of combustion chambers of liquid rocket engines required the creation of new ways to protect the surface layer of the hot zone from the effects of the flame in the fuel combustion zone. The possibilities for using of plasma application of metal-ceramic heat-protective coatings for these purposes, which have good erosion resistance and high thermal resistance in conditions of intense exposure to high-temperature combustion products, are revealed. The analysis of the effect of the quality of the coatings surface layer on the performance characteristics of the product is presented. The need for local finishing of the applied coatings is justified, including in the transition areas of the combustion chambers and the jet nozzle, which have limited tool access to the processing zone. The most effective method is the combined alignment of the microprofile with the imposition of electric field. But for its implementation, set of studies is needed to study the mechanism of allowance removing, and to adjust the technological modes. The task of minimizing allowances for finishing combined processing is solved, which allowed to align the thickness of the heat-protective coating along the length of the fuel combustion path, including the cleaning sections, to increase the number of trouble-free engine starts by 1.5...2.0 times and ensure reusable use of product.

scholarly journals The stability of capillary waves on fluid sheets

2016 ◽  
Vol 806 ◽  
pp. 5-34 ◽  
Author(s):  
M. G. Blyth ◽  
E. I. Părău
Keyword(s):  
Nonlinear Waves ◽  
Time Integration ◽  
Lower Surface ◽  
Finite Amplitude ◽  
Capillary Waves ◽  
Mapping Technique ◽  
Surprising Result ◽  
Periodic Waves ◽  
The Stability ◽  
The Waves

The linear stability of finite-amplitude capillary waves on inviscid sheets of fluid is investigated. A method similar to that recently used by Tiron & Choi (J. Fluid Mech., vol. 696, 2012, pp. 402–422) to determine the stability of Crapper waves on fluid of infinite depth is developed by extending the conformal mapping technique of Dyachenko et al. (Phys. Lett. A, vol. 221 (1), 1996a, pp. 73–79) to a form capable of capturing general periodic waves on both the upper and the lower surface of the sheet, including the symmetric and antisymmetric waves studied by Kinnersley (J. Fluid Mech., vol. 77 (02), 1976, pp. 229–241). The primary, surprising result is that both symmetric and antisymmetric Kinnersley waves are unstable to small superharmonic disturbances. The waves are also unstable to subharmonic perturbations. Growth rates are computed for a range of steady waves in the Kinnersley family, and also waves found along the bifurcation branches identified by Blyth & Vanden-Broeck (J. Fluid Mech., vol. 507, 2004, pp. 255–264). The instability results are corroborated by time integration of the fully nonlinear unsteady equations. Evidence is presented for superharmonic instability of nonlinear waves via a collision of eigenvalues on the imaginary axis which appear to have the same Krein signature.

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