Dynamic Response of a Metal and a CMC Turbine Blade During a Controlled Rub Event Using a Segmented Shroud

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Nisrene Langenbrunner ◽  
Matt Weaver ◽  
Michael G. Dunn ◽  
Corso Padova ◽  
Jeffery Barton
Keyword(s):  
Dynamic Response ◽  
Turbine Blade ◽  
Engine Performance ◽  
Ceramic Matrix Composites ◽  
Matrix Composites ◽  
Cooperative Research ◽  
Temperature Capability ◽  
Blade Tip ◽  
The Ohio State University ◽  
Design Speed

Ceramic matrix composites (CMCs) provide several benefits over metal blades including weight and increased temperature capability, and have the potential for increased engine performance by reduction of the cooling flow bled from the compressor and by allowing engines to run at higher turbine inlet temperatures. These CMC blades must be capable of surviving fatigue (high cycle and low cycle), creep, impact, and any tip rub events due to the engine missions or maneuvers that temporarily close blade tip/shroud clearances. As part of a cooperative research program between GE Aviation and the Ohio State University Gas Turbine Laboratory, OSU GTL, the response of a CMC stage 1 low-pressure turbine blade has been compared with the response of an equivalent metal turbine blade using the OSU GTL large spin-pit facility (LSPF) as the test vehicle. Load cells mounted on the casing wall, strain gages mounted on the airfoils, and other instrumentation are used to assess blade tip rub interactions with a 120-deg sector of a representative turbine stationary casing. The intent of this paper is to present the dynamic response of both the CMC and the metal blades with the turbine disk operating at design speed and with representative incursion rates and depths. Casing wear and blade tip wear are both characterized for several types of rub conditions including a light, medium, and heavy rub at room temperature. For each condition, the rub primary dynamic modes have been evaluated, and the corresponding blade tip loads have been calculated. The preliminary results suggest that a CMC blade has similar abilities to a metal blade during a rub event.

Dynamic Response of a Metal and a CMC Turbine Blade During a Controlled Rub Event Using a Segmented Shroud

2014 ◽  
Author(s):  
Nisrene Langenbrunner ◽  
Matt Weaver ◽  
Michael G. Dunn ◽  
Corso Padova ◽  
Jeffery Barton
Keyword(s):  
Dynamic Response ◽  
Turbine Blade ◽  
Engine Performance ◽  
Ceramic Matrix Composites ◽  
Matrix Composites ◽  
Temperature Capability ◽  
Blade Tip ◽  
The Ohio State University ◽  
Design Speed ◽  
Stage 1

Ceramic Matrix Composites, CMCs, provide several benefits over metal blades including weight and increased temperature capability, and have the potential for increased engine performance by reduction of the cooling flow bled from the compressor and by allowing engines to run at higher turbine inlet temperatures. These CMC blades must be capable of surviving fatigue (high cycle and low cycle), creep, impact, and any tip rub events due to the engine missions or maneuvers that temporarily close blade tip/shroud clearances. As part of a co-operative research program between GE Aviation and the Ohio State University Gas Turbine Laboratory, OSU GTL, the response of a CMC stage 1 low-pressure turbine blade has been compared with the response of an equivalent metal turbine blade using the OSU GTL large spin-pit facility (LSPF) as the test vehicle. Load cells mounted on the casing wall, strain gages mounted on the airfoils, and other instrumentation are used to assess blade tip rub interactions with a 120-degree sector of a representative turbine stationary casing. The intent of this paper is to present the dynamic response of both the CMC and the metal blades with the turbine disk operating at design speed and with representative incursion rates and depths. Casing wear and blade tip wear are both characterized for several types of rub conditions including a light, medium, and heavy rub at room temperature. For each condition, the rub primary dynamic modes have been evaluated, and the corresponding blade tip loads have been calculated. The preliminary results suggest that a CMC blade has similar abilities to a metal blade during a rub event.

scholarly journals Applications of Continuous Fiber Reinforced Ceramic Composites in Military Turbojet Engines

1996 ◽  
Author(s):  
Patrick Spriet ◽  
Georges Habarou
Keyword(s):  
Weight Ratio ◽  
Ceramic Matrix Composites ◽  
Thermodynamic Cycle ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Continuous Fiber ◽  
Operating Life ◽  
Performance Improvements ◽  
Temperature Capability

Over the last twenty years, significant performance improvements of turbojet engines have been achieved by optimizing engine thermodynamic cycle along with the introduction of new materials providing higher temperature capability and weight reduction. Metal Matrix Composites (MMC) and Ceramic Matrix Composites (CMC) are candidate material systems to meet the required thrust-to-weight ratio of 15 or higher. Continuous fiber reinforced ceramic composites, which have been developed by SEP for more than 15 years for thermostructural applications in oxidative environment, aim at increased operating temperature over superalloys and intermetallic alloys. This paper is a review of the main CMC component demonstrations performed by SEP over the last 10 years for turbojet engines along with an analysis of consequences on materials development and design methodology. The development status of a new thermostructural material specifically developed for turbojet environment with the prospect of higher design stress allowables and longer operating life at high temperature is presented.

Development and Evaluation of Environmental Barrier Coatings for Silicon Nitride

2002 ◽  
Author(s):  
Ellen Y. Sun ◽  
Harry E. Eaton ◽  
John E. Holowczak ◽  
Gary D. Linsey
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Ceramic Matrix Composites ◽  
Turbine Engines ◽  
Matrix Composites ◽  
Gas Turbine Engines ◽  
Barrier Coatings ◽  
Environmental Barrier Coatings ◽  
Environmental Barrier ◽  
Temperature Capability

Environmental barrier coatings (EBCs) are required for applications of silicon nitride (Si3N4) and silicon carbide (SiC) based materials in gas turbine engines because of the accelerated oxidation of Si3N4 and SiC and subsequent volatilization of silica in the high temperature high-pressure steam environment. EBC systems for silicon carbide fiber reinforced silicon carbide ceramic matrix composites (SiC/SiC CMC’s) were first developed and have been demonstrated via long-term engine tests. Recently, studies have been carried out at United Technologies Research Center (UTRC) to understand the temperature capability of the current celsian-based EBC systems and its suitability for silicon nitride ceramics concerning thermal expansion mismatch between the EBC coating and silicon nitride substrates. This paper will present recent progress in improving the temperature capability of the celsian –based EBC systems and discuss their effectiveness for silicon nitride.

Cooling the Tip of a Turbine Blade Using Pressure Side Holes—Part I: Adiabatic Effectiveness Measurements

2005 ◽  
Vol 127 (2) ◽  
pp. 270-277 ◽  
Author(s):  
J. R. Christophel ◽  
K. A. Thole ◽  
F. J. Cunha
Keyword(s):  
Turbine Blade ◽  
Film Cooling ◽  
Large Scale ◽  
Engine Performance ◽  
Pressure Side ◽  
Transfer Coefficients ◽  
Turbine Engine ◽  
Flow Phenomena ◽  
Blade Tip ◽  
Adiabatic Effectiveness

Durability of turbine blade tips has been and continues to be challenging, particularly since increasing turbine inlet temperatures is the driver for improving turbine engine performance. As a result, cooling methods along the blade tip are crucial. Film-cooling is one typically used cooling method whereby coolant is supplied through holes placed along the pressure side of a blade. The subject of this paper is to evaluate the adiabatic effectiveness levels that occur on the blade tip through blowing coolant from holes placed near the tip of a blade along the pressure side. A range of blowing ratios was studied whereby coolant was injected from holes placed along the pressure side tip of a large-scale blade model. Also present were dirt purge holes on the blade tip, which is part of a commonly used blade design to expel any large particles present in the coolant stream. Experiments were conducted in a linear cascade with a scaled-up turbine blade whereby the Reynolds number of the engine was matched. This paper, which is Part 1 of a two part series, compares adiabatic effectiveness levels measured along a blade tip, while Part 2 combines measured heat transfer coefficients with the adiabatic effectiveness levels to assess the overall cooling benefit of pressure side blowing near a blade tip. The results show much better cooling can be achieved for a small tip gap compared with a large tip gap with different flow phenomena occurring for each tip gap setting.

scholarly journals Continuous Fiber Ceramic Matrix Composites for Gas Turbine Applications

1999 ◽  
Author(s):  
A. Szweda ◽  
T. E. Easler ◽  
D. R. Petrak ◽  
V. A. Black
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Gas Turbine ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Continuous Fiber ◽  
Temperature Capability ◽  
Polymer Impregnation

Continuous fiber ceramic composites (CFCCs) are being considered as high temperature structural materials for gas turbine applications due to their high temperature capability, toughness, and durability. Polymer impregnation and pyrolysis (PIP) derived CFCCs are one class of these materials that can be fabricated using widely available polymer composite processing methods. This paper will discuss the general PIP fabrication process and thermo-mechanical properties of these materials, and show examples of complex prototype gas turbine components that have been fabricated and evaluated.

Cooling the Tip of a Turbine Blade Using Pressure Side Holes: Part 1 — Adiabatic Effectiveness Measurements

2004 ◽  
Author(s):  
J. R. Christophel ◽  
K. A. Thole ◽  
F. J. Cunha
Keyword(s):  
Turbine Blade ◽  
Film Cooling ◽  
Engine Performance ◽  
Turbine Engines ◽  
Pressure Side ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Flow Phenomena ◽  
Blade Tip ◽  
Adiabatic Effectiveness

Sealing and durability for turbine blade tips have been challenging problems since the development of gas turbine engines. Blade tip designs are extremely important in terms of sealing and engine performance. In general, overall engine performance can be improved by increasing turbine inlet temperatures. As a result, cooling methods along the blade tip need to be devised and applied effectively. Film-cooling is typically used as a blade tip cooling method, whereby coolant is supplied through holes placed along the pressure side of a blade. Experiments were conducted in a linear cascade with a scaled-up turbine blade whereby the Reynolds number of the engine was matched. A range of blowing ratios was studied whereby coolant was injected from holes placed along the pressure side tip of the blade as well as from dirt purge holes placed on the blade tip. This paper, which is Part 1 of a two part series, compares adiabatic effectiveness levels measured along a blade tip, while Part 2 combines measured heat transfer coefficients with the adiabatic effectiveness levels to assess the overall cooling benefit of pressure side blowing near a blade tip. The results show better cooling can be achieved for a small tip gap compared with a large tip gap with different flow phenomena occurring for each tip gap setting.

Turbine Blade Tip Clearance Improvement

1991 ◽  
Author(s):  
B. Glezer
Keyword(s):  
Turbine Blade ◽  
Operating Experience ◽  
Engine Performance ◽  
Tip Clearance ◽  
Analytical Prediction ◽  
Term Operation ◽  
Extensive Field ◽  
Blade Tip ◽  
Blade Tip Clearance

A recently developed non-traditional design concept addressing turbine blade tip clearance reduction to provide long-term engine performance improvement and stability is presented. The concept is based on the direct attachment of the diaphragm, which supports Stage 1 integral nozzle and tips shroud segments, to the bearing housing, thus providing a close thermal link between the rotor and the stator. Transient thermal matching between the rotating and stationary structures was based on analytical prediction. Results of the complex turbine hot section study including cooling flow, thermal, stress, and deflection analyses are presented. An advanced tip clearance measurement technique was used in the full scale engine test to verify the analytical predictions. The potential to reduce tip clearance to less than 1% of blade height without blade tip rubs has been demonstrated. Extensive field operating experience with more than 100 Centaur Type ‘H’ engines showed very light or no blade tip rub and corresponding engine performance stability during long-term operation.

The Effects of Cooling Holes on SiC/SiC CMC Tensile Strength

2020 ◽  
Author(s):  
Craig Smith ◽  
Michael Presby ◽  
Ramakrishna Bhatt ◽  
Sreeramesh Kalluri
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Film Cooling ◽  
Mechanical Test ◽  
Engine Performance ◽  
Ceramic Matrix Composites ◽  
Image Correlation ◽  
Matrix Composites ◽  
High Temperature Components ◽  
Multiple Holes

Abstract Silicon Carbide fiber-reinforced Silicon Carbide (SiC/SiC) Ceramic Matrix Composites (CMCs) are currently operating in select high temperature components of turbine engines. Primary benefits of CMCs compared to metals are improved temperature capability, reduced cooling requirements and reduced component weight. High temperature materials require less cooling air to be diverted from the compressor, resulting in improved engine performance. However, some amount of film cooling may be necessary when CMCs are implemented in higher temperature applications. Film cooling requires holes to be fabricated at appropriate locations and orientations within these components. It is important to understand how such holes will affect the material properties. While previous studies have shown that CMCs are notch insensitive, the effect of multiple holes and different hole orientations on SiC/SiC CMCs is not well documented. This study examines the effect of cooling holes on SiC/SiC tensile properties. Several hole geometries fabricated in SiC/SiC samples are explored. Mechanical test data on specimens with multiple holes is reported for tensile loading at room temperature. Tools such as Digital Image Correlation (DIC) and Acoustic Emission (AE) are used to monitor strain and cracking in the CMC upon loading.

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