scholarly journals Effect of the MoSi2 coating on operational reliability of bipropellant rocket engine

2021 ◽  
Vol 260 ◽  
pp. 03003
Author(s):  
Kun Cai ◽  
Zhen Zhang ◽  
Na Wang ◽  
Yu Hu ◽  
Fengshan Wang
Keyword(s):  
High Temperature ◽  
Liquid Film ◽  
Film Cooling ◽  
Thermal Cycle ◽  
High Speed ◽  
Rocket Engine ◽  
Operational Reliability ◽  
Rocket Engines ◽  
Self Healing ◽  
Mosi2 Coating

This present study investigated the MoSi2 coating and its effect on reliability of bipropellant rocket engine. This coating is developed to protect the chamber substrate material form oxidization under hightemperature oxidative circumstance as bipropellant engine works. The multilayer structure of the MoSi2 coating shows excellent high-temperature and thermal-cycle resistance. Its characteristic of self-healing leads to the good performance under the long-time steady working condition for rocket engines. A 25000-seconds firing test was conducted to testify the performance of MoSi2 coating under high temperature above 1400℃. In addition, the influence of coating surface morphology on liquid film cooling was fully discussed in experiment and simulation. High-speed microscopy camera was used to study the effects of Weber number on the spreading and lasting of cooling liquid-film. the simulative comparison was conducted by OpenFOAM to present different transfer-heat modes, when a droplet impinges on the high-temperature surface of MoSi2 coating. All results show that higher smoothness of the coating is suitable for liquid-film cooling, strengthening liquid film spread and heat transfer. Moreover, scanning electron microscope (SEM) was used to study the effect of Mo layer residue on the coating thermal-cycle profermance. The test results indicates that Mo layer residue significantly cause penetrating cracks of the coating and then weaken the self-healing of the coating at downstream of throat. Therefore, it is important to strictly control the thickness of Mo layer by means of matching Mo target in ion plating. Thus after properly prolonging the infiltration time, Mo layer can be silicified completely without residue.

scholarly journals Numerical Simulation of Reactive Flows in Overexpanded Supersonic Nozzle with Film Cooling

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Mohamed Sellam ◽  
Amer Chpoun
Keyword(s):  
Film Cooling ◽  
Structural Integrity ◽  
Safety Issue ◽  
Rocket Engine ◽  
Supersonic Nozzle ◽  
Nozzle Geometry ◽  
Nozzle Flow ◽  
Rocket Engines ◽  
Flow Conditions ◽  
Reactive Flows

Reignition phenomena occurring in a supersonic nozzle flow may present a crucial safety issue for rocket propulsion systems. These phenomena concern mainly rocket engines which use H2gas (GH2) in the film cooling device, particularly when the nozzle operates under over expanded flow conditions at sea level or at low altitudes. Consequently, the induced wall thermal loads can lead to the nozzle geometry alteration, which in turn, leads to the appearance of strong side loads that may be detrimental to the rocket engine structural integrity. It is therefore necessary to understand both aerodynamic and chemical mechanisms that are at the origin of these processes. This paper is a numerical contribution which reports results from CFD analysis carried out for supersonic reactive flows in a planar nozzle cooled with GH2film. Like the experimental observations, CFD simulations showed their ability to highlight these phenomena for the same nozzle flow conditions. Induced thermal load are also analyzed in terms of cooling efficiency and the results already give an idea on their magnitude. It was also shown that slightly increasing the film injection pressure can avoid the reignition phenomena by moving the separation shock towards the nozzle exit section.

Source Term Based Modeling of Rotating Cavitation in Turbopumps

2018 ◽  
Author(s):  
A. G. Vermes ◽  
C. Lettieri
Keyword(s):  
Price Competition ◽  
High Speed ◽  
Large Scale ◽  
Source Term ◽  
Experimental Testing ◽  
Rocket Engine ◽  
Computational Cost ◽  
Flow Coefficient ◽  
Rocket Engines ◽  
Launch Vehicles

The recent growth of private options in launch vehicles has substantially raised price competition in the space launch market. This has increased the need to deliver reliable launch vehicles at reduced engine development cost, and has led to increased industrial interest in reduced order models. Large-scale liquid rocket engines require high-speed turbopumps to inject cryogenic propellants into the combustion chamber. These pumps can experience cavitation instabilities even when operating near design conditions. Of particular concern is rotating cavitation, which is characterized by an asymmetric cavity rotating at the pump inlet, which can cause severe vibration, breaking of the pump and loss of the mission. Despite much work in the field, there are limited guidelines to avoid rotating cavitation during design and its occurrence is often assessed through costly experimental testing. This paper presents a source term based model for stability assessment of rocket engine turbopumps. The approach utilizes mass and momentum source terms to model cavities and hydrodynamic blockage in inviscid, single-phase numerical calculations, reducing the computational cost of the calculations by an order of magnitude compared to traditional numerical methods. Comparison of the results from the model with experiments and high-fidelity calculations indicates agreement of the head coefficient and cavity blockage within 0.26% and 5% respectively. The computations capture rotating cavitation in a 2D inducer at the expected flow coefficient and cavitation number. The mechanism of formation and propagation of the instability is correctly reproduced.

Properties and Application of Alumina Reinforced Aluminum Composite

2013 ◽  
Vol 853 ◽  
pp. 68-72 ◽  
Author(s):  
Ya Nan Li ◽  
Wei Zheng Zhang ◽  
Yuan Fu Cao ◽  
Ti En Zhang
Keyword(s):  
High Temperature ◽  
High Intensity ◽  
High Speed ◽  
Operational Reliability ◽  
High Temperature Strength ◽  
Alumina Fiber ◽  
Fiber Reinforced ◽  
Cast Aluminum ◽  
Aluminum Composite ◽  
Core Technology

Improving high-temperature strength of aluminum piston material is a core technology for diesel engines to high speed and high intensity. To figure out the influence of alumina reinforced aluminum composites to the thermal load of high intensity piston, this paper study the properties of the alumina fiber reinforced aluminum composite and its protection for piston. The research shows that, compared with the cast aluminum, the high tensile strength and fatigue limit of the composite were increased by about 25% and 26% respectively. Therefore, the alumina fiber reinforced composite could not improve the temperature distribution of the piston, but it can improve high temperature strength and the operational reliability of the piston.

High Temperature Turbine Researches at National Aerospace Laboratory in Japan

1974 ◽  
Author(s):  
K. Takahara ◽  
M. Sasaki ◽  
M. Minoda ◽  
A. Yamamoto ◽  
H. Nouse ◽  
...  
Keyword(s):  
High Temperature ◽  
Turbine Blade ◽  
Film Cooling ◽  
High Speed ◽  
Turbine Blades ◽  
Axial Flow ◽  
Leading Edge ◽  
Performance Estimation ◽  
New Construction ◽  
Full Scale Tests

This paper reviews the basic researches of high temperature turbines. These researches include: the performance estimation of a turbo-fan engine with an air-cooled turbine; the relation between the spanwise distribution of cooling effectiveness and the life of the air-cooled turbine blade; experiments of film cooling on the leading edge and on the reduction of unsteady thermal stress in the air-cooled turbine blade; and a new construction of the air-cooled turbine blade. Also discussed are the two-dimensional cascade tests of air-cooled turbine blades by the low-speed and high-speed wind tunnels. Full-scale tests for the high temperature turbine including aerodynamic and thermodynamic investigations of air-cooled axial flow turbines are shown.

scholarly journals Numerical study of operational processes in a GOx-kerosene rocket engine with liquid film cooling

2020 ◽  
Vol 9 (2) ◽  
pp. 132-141
Author(s):  
Evgenij A. Strokach ◽  
Igor N. Borovik ◽  
Vladimir G. Bazarov ◽  
Oscar J. Haidn
Keyword(s):  
Liquid Film ◽  
Film Cooling ◽  
Numerical Study ◽  
Rocket Engine ◽  
Operational Processes

scholarly journals A Film-Cooling CFD Bibliography: 1971–1996

1998 ◽  
Vol 4 (1) ◽  
pp. 61-72 ◽  
Author(s):  
D. M. Kercher
Keyword(s):  
High Temperature ◽  
Film Cooling ◽  
Gas Turbines ◽  
Turbulence Modeling ◽  
Three Dimensional ◽  
Design Tool ◽  
Navier Stokes ◽  
Experimental Investigations ◽  
Rocket Engines ◽  
Development Environment

After more than 25 years of three-dimensional film cooling experimental investigations, analytical correlations and modeling, film cooling utilizing computational fluid dynamics has emerged from a similar development-applications growth process into a near-attainable heat transfer engineering tool. Analytical applications include high temperature subsonic to hypersonic flow with complex wall-geometry coolant injection film performance analysis techniques spanning usage from gas turbines to rocket engines to scramjets. In recent years there has been significant development in increased computer power and modeling capacity, increasingly more complex and successful Navier-Stokes turbulence modeling techniques, innovative labor-saving meshing techniques, and more successful validation of experimental results. These combined innovations have continued to transition computational film cooling technology from the academic, government and commercial research and development environment to the industrial design-analysis environment. This bibliography is an openliterature reference resource whose papers collectively describe the continual emerging of numerical film cooling as a viable design tool for high temperature components.

Source Term Based Modeling of Rotating Cavitation in Turbopumps

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
A. G. Vermes ◽  
C. Lettieri
Keyword(s):  
Price Competition ◽  
High Speed ◽  
Large Scale ◽  
Source Term ◽  
Experimental Testing ◽  
Rocket Engine ◽  
Computational Cost ◽  
Flow Coefficient ◽  
Rocket Engines ◽  
Launch Vehicles

The recent growth of private options in launch vehicles has substantially raised price competition in the space launch market. This has increased the need to deliver reliable launch vehicles at reduced engine development cost and has led to increased industrial interest in reduced order models. Large-scale liquid rocket engines require high-speed turbopumps to inject cryogenic propellants into the combustion chamber. These pumps can experience cavitation instabilities even when operating near design conditions. Of particular concern is rotating cavitation (RC), which is characterized by an asymmetric cavity rotating at the pump inlet, which can cause severe vibration, breaking of the pump, and loss of the mission. Despite much work in the field, there are limited guidelines to avoid RC during design and its occurrence is often assessed through costly experimental testing. This paper presents a source term based model for stability assessment of rocket engine turbopumps. The approach utilizes mass and momentum source terms to model cavities and hydrodynamic blockage in inviscid, single-phase numerical calculations, reducing the computational cost of the calculations by an order of magnitude compared to traditional numerical methods. Comparison of the results from the model with experiments and high-fidelity calculations indicates agreement of the head coefficient and cavity blockage within 0.26% and 5%, respectively. The computations capture RC in a two-dimensional (2D) inducer at the expected flow coefficient and cavitation number. The mechanism of formation and propagation of the instability is correctly reproduced.

ROCKET ENGINE WITH CONTINUOUSLY ROTATING LIQUID-FILM DETONATION

2019 ◽  
Author(s):  
S.M. FROLOV ◽  
◽  
I.O. SHAMSHIN ◽  
V.S. AKSENOV ◽  
I.A. SADYKOV ◽  
...  
Keyword(s):  
Liquid Film ◽  
Rocket Engine ◽  
Rotating Liquid

ALX ALLOY

Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Speed ◽  
Heat Treating ◽  
Temperature Performance ◽  
Cobalt Base

Abstract ALX is a composition of nonferrous materials with a cobalt base containing chromium, tungsten and carbon. This alloy is commonly supplied in the cast-to-shape form, having an as-cast hardness of Rockwell C60-62 and requiring no further heat treatment. ALX is also supplied as cast tool bit material and is useful where conventional high-speed steels or carbides do not function effectively. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, forming, heat treating, and machining. Filing Code: Co-35. Producer or source: Allegheny Ludlum Corporation.

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