Design and Implementation of Actively Cooled Panels for Scramjets

2007 ◽  
Author(s):  
Natasha Vermaak ◽  
Lorenzo Valdevit ◽  
Frank W. Zok ◽  
Anthony G. Evans
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Design Tool ◽  
Heat Fluxes ◽  
Operating Conditions ◽  
Advanced Materials ◽  
Matrix Composites ◽  
High Temperature Alloys ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses

The operating conditions of scramjet engines demand designs that include active cooling by the fuel and the use of lightweight materials that withstand extreme heat fluxes and structural loads. An optimization tool has previously been introduced to direct the development of advanced materials that outperform existing high temperature alloys and compete with ceramic matrix composites. This analysis presents verification and accretion of the analytical design tool through a combination of numerical and experimental techniques. Selected computational fluid dynamics (CFD) analyses have been performed to verify critical thermal assumptions. A high-power CO2 laser provides heat fluxes representative of hypersonic flight conditions.

scholarly journals Exposure of Ceramics and Ceramic Matrix Composites in Simulated and Actual Combustor Environments

2000 ◽  
Vol 122 (2) ◽  
pp. 212-218 ◽  
Author(s):  
Karren L. More ◽  
Peter F. Tortorelli ◽  
Mattison K. Ferber ◽  
Larry R. Walker ◽  
James R. Keiser ◽  
...  
Keyword(s):  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Surface Damage ◽  
Operating Conditions ◽  
Matrix Composites ◽  
Long Term Stability ◽  
Recession Rates ◽  
Combustor Liner

A high-temperature, high-pressure, tube furnace has been used to evaluate the long term stability of different monolithic ceramic and ceramic matrix composite materials in a simulated combustor environment. All of the tests have been run at 150 psia, 1204°C, and 15 percent steam in incremental 500 h runs. The major advantage of this system is the high sample throughput; >20 samples can be exposed in each tube at the same time under similar exposure conditions. Microstructural evaluations of the samples were conducted after each 500 h exposure to characterize the extent of surface damage, to calculate surface recession rates, and to determine degradation mechanisms for the different materials. The validity of this exposure rig for simulating real combustor environments was established by comparing materials exposed in the test rig and combustor liner materials exposed for similar times in an actual gas turbine combustor under commercial operating conditions. [S0742-4795(00)02402-9]

scholarly journals Exposure of Ceramics and Ceramic Matrix Composites in Simulated and Actual Combustor Environments

1999 ◽  
Author(s):  
Karren L. More ◽  
Peter F. Tortorelli ◽  
Mattison K. Ferber ◽  
Larry R. Walker ◽  
James R. Keiser ◽  
...  
Keyword(s):  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Surface Damage ◽  
Operating Conditions ◽  
Matrix Composites ◽  
Long Term Stability ◽  
Recession Rates ◽  
Combustor Liner

A high-temperature, high-pressure, tube furnace has been used to evaluate the long term stability of different monolithic ceramic and ceramic matrix composite materials in a simulated combustor environment. All of the tests have been run at 150 psia, 1204°C, and 15% steam in incremental 500 h runs. The major advantage of this system is the high sample throughput; >20 samples can be exposed in each tube at the same time under similar exposure conditions. Microstructural evaluations of the samples were conducted after each 500 h exposure to characterize the extent of surface damage, to calculate surface recession rates, and to determine degradation mechanisms for the different materials. The validity of this exposure rig for simulating real combustor environments was established by comparing materials exposed in the test rig and combustor liner materials exposed for similar times in an actual gas turbine combustor under commercial operating conditions.

Strength Degradation of Oxide/Oxide and SiC/SiC Ceramic Matrix Composites in CMAS and CMAS/Salt Exposures

2011 ◽  
Author(s):  
David C. Faucett ◽  
Sung R. Choi
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Strength Degradation ◽  
Operating Conditions ◽  
Thermal Barrier ◽  
Matrix Composites ◽  
Thermal Cycling Condition ◽  
Sic Ceramic ◽  
Calcium Magnesium ◽  
Cycling Condition

CMAS (Calcium-Magnesium-Aluminosilicate) has shown to induce some deleterious effects on yittria-stabilized-zirconia (YSZ) based thermal barrier coatings (TBCs) of hot section components of aeroengines. The effects were shown to be dependent on the types and operating conditions of engines/components. The work presented here explored how CMAS would affect ceramic matrix composites (CMCs) in terms of strength degradation. Four different, gas-turbine grade CMCs were utilized including two types of MI SiC/SiCs and other two types of oxides/oxides (N720/aluminisilicate and N720/alumina). Test specimens in a simple flexure configuration were CMAS-treated at 1200 °C in air under either isothermal or thermal cycling condition. The effects of CMAS were quantified via residual strengths of treated test specimens. Strength degradation with respect to as-received strengths ranged from 10 to 20% depending on the types of CMCs. It was further observed that significant degradation of strength up to 90% occurred in an oxide/oxide CMC when sodium sulfate was added to CMAS.

PERFORMANCE DIAGRAMS FOR CERAMIC MATRIX COMPOSITE COMPONENTS SUBJECTED TO CYCLIC THERMO-MECHANICAL LOADING

2009 ◽  
Vol 01 (03n04) ◽  
pp. 433-450
Author(s):  
A. C. F. COCKS ◽  
F. A. LECKIE
Keyword(s):  
Thermal Loading ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Operating Conditions ◽  
Matrix Composites ◽  
Cyclic Thermal Loading ◽  
Failure Conditions ◽  
Extent Of Damage ◽  
Safe Operating

Ceramic matrix composites (CMCs) are candidates for pressurized tubes which operate under conditions of severe cyclic thermal loading. Simple models describing the properties of CMCs are used to estimate the behaviour of a pressurized tube subjected to cyclic thermal loading and to establish shakedown and failure conditions. Analytical procedures are described which evaluate the component response in the cyclic state. The approach is illustrated by analysing the classical Bree problem assuming material properties which are representative of a SiC/SiC composite. Performance diagrams are presented which identify safe operating conditions and the extent of damage in the component.

A Study of Bridged Delaminations in High Temperature Laminates Under Heat Flux Loading

Materials ◽  
2003 ◽  
Author(s):  
Thomas Siegmund ◽  
Ashwin Hattiangadi
Keyword(s):  
Heat Flux ◽  
High Temperature ◽  
Thermal Loading ◽  
Significant Contribution ◽  
Thermal Protection ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
High Heat ◽  
Heat Fluxes ◽  
Matrix Composites

High temperature ceramic matrix composites (CMCs) are material considered in many applications where high heat fluxes constitute a significant contribution to loading. The laminates can fulfill their function as thermal protection layers only if they stay intact, i.e. without internal delaminations or spalling, such that the heat flux remains undisturbed by such events. Crack bridging is an important effect in CMCs, and its implication to CMC laminates under thermal loading is investigated.

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