Design Considerations for Ceramic Matrix Composite High Pressure Turbine Blades

2019 ◽  
Author(s):  
Robert J. Boyle ◽  
Ankur H. Parikh ◽  
Vinod K. Nagpal
Keyword(s):  
High Pressure ◽  
Matrix Composite ◽  
Turbine Blades ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix ◽  
Aircraft Engine ◽  
Time Frame ◽  
Rotor Blades ◽  
High Pressure Turbine ◽  
Directional Variation

Abstract Issues associated with using SiC/SiC Ceramic Matrix Composite (CMC) materials for High Pressure Turbine (HPT) rotor blades are explored. SiC/SiC materials have higher temperature capability than current HPT superalloys. The strength versus temperature characteristics of SiC/SiC CMCs differs from that of superalloys. Stress analyses were done for a NASA specified notional single aisle aircraft engine blade to be available in the N+3 time frame, (beyond 2030). Stacking, the relative position of hub and tip sections, depends on both pressure and centrifugal forces, and material density. The effect of blade stacking on blade stresses is examined. The change in stresses as the rotation rate varies is examined. The change in engine weight, and thus fuel consumption, due to changes in engine size as the rpm changes is discussed. SiC/SiC CMC materials are generally not isotropic. The effect on stresses and strains of a directional variation in Young’s modulus is examined. Shrouding metallic HPT rotor blades is not common. Shrouding SiC/SiC CMC rotor blades may be feasible due to the lower density, and thus lower centrifugal loads, of SiC/SiC blades. The increase in stresses due to shrouding a SiC/SiC blade is discussed.

scholarly journals Design Considerations for Ceramic Matrix Composite Vanes for High Pressure Turbine Applications

2013 ◽  
Author(s):  
Robert J. Boyle ◽  
Ankur H. Parikh ◽  
Michael C. Halbig ◽  
Vinod K. Nagpal
Keyword(s):  
High Pressure ◽  
Matrix Composite ◽  
Film Cooling ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix ◽  
Temperature Gradients ◽  
High Pressure Turbine ◽  
Trailing Edge ◽  
Temperature Capability ◽  
Higher Temperature

Issues associated with replacing conventional metallic vanes with Ceramic Matrix Composite(CMC) vanes in the first stage of the High Pressure Turbine(HPT) are explored. CMC materials have higher temperature capability than conventional HPT vanes, and less vane cooling is required. The benefits of less vane coolant are less NOx production and improved vane efficiency. Comparisons between CMC and metal vanes are made at current rotor inlet temperatures and at an vane inlet pressure of 50 atm.. CMC materials have directionally dependent strength characteristics, and vane designs must accommodate these characteristics. The benefits of reduced NOx and improved cycle efficiency obtainable from using CMC vanes. are quantified Results are given for vane shapes made of a two dimensional CMC weave. Stress components due to thermal and pressure loads are shown for all configurations. The effects on stresses of: (1) a rib connecting vane pressure and suction surfaces; (2) variation in wall thickness; and (3) trailing edge region cooling options are discussed. The approach used to obtain vane temperature distributions is discussed. Film cooling and trailing edge ejection were required to avoid excessive vane material temperature gradients. Stresses due to temperature gradients are sometimes compressive in regions where pressure loads result in high tensile stresses.

scholarly journals Shrouded CMC Rotor Blades for High Pressure Turbine Applications

2018 ◽  
Author(s):  
Robert J. Boyle ◽  
Lucas M. Agricola ◽  
Ankur H. Parikh ◽  
Ali A. Ameri ◽  
Vinod K. Nagpal
Keyword(s):  
High Pressure ◽  
Turbine Blades ◽  
Ceramic Matrix Composite ◽  
Rotor Blades ◽  
Navier Stokes ◽  
High Pressure Turbine ◽  
Aerodynamic Efficiency ◽  
Stress Maximum ◽  
Measured Efficiency ◽  
Maximum Stresses

The density of Ceramic Matrix Composite (CMC) materials is approximately 1/3 the density of metals currently used for High Pressure Turbine (HPT) blades. A lower density, and consequently lower centrifugal stresses, increases the feasibility of shrouding HPT blades. Shrouding HPT blades improves aerodynamic efficiency, especially for low aspect ratio turbine blades. This paper explores aerodynamic and structural issues associated with shrouding HPT rotor blades. Detailed Navier-Stokes analysis of a rotor blade showed that shrouding improved blade row aerodynamic efficiency by 1.3%, when the clearance was 2% of the blade span. Recessed casings were used. Without a shroud the depth of the recess equaled the clearance. With a shroud the recess depth increased by the shroud thickness, which included a knife seal. There was good agreement between the predicted stage efficiency for the unshrouded blades and the experimentally measured efficiency. Structural analysis showed a strong interaction between stresses in the shroud and peak stresses at the hub of the blade. A thin shroud of uniform thickness only moderately increased maximum blade stress, but there were very high stresses in the shroud itself. Increasing shroud thickness reduced stresses in the shroud, but increased blade stresses near the hub. A single knife seal added to the thin shroud noticeably decreased maximum shroud stress, without increasing maximum blade stress. Maximum stresses due to pressure loads and combined pressure and centrifugal loads were nearly the same as the maximum stresses for individual pressure or centrifugal loads. Stresses due to a 100K temperature difference across the blade walls were much lower than centrifugal or pressure load stresses.

scholarly journals Ceramic Matrix Composite Vane Subelement Burst Testing

2006 ◽  
Author(s):  
David N. Brewer ◽  
Michael Verrilli ◽  
Anthony Calomino
Keyword(s):  
High Pressure ◽  
Matrix Composite ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix ◽  
Environmental Barrier ◽  
Environmental Barrier Coating ◽  
Barrier Coating

Burst tests were performed on Ceramic Matrix Composite (CMC) vane specimens, manufactured by two vendors, under the Ultra Efficient Engine Technology (UEET) project. Burst specimens were machined from the ends of 76mm long vane sub-elements blanks and from High Pressure Burner Rig (HPBR) tested specimens. The results of burst tests will be used to compare virgin specimens with specimens that have had an Environmental Barrier Coating (EBC) applied, both HPBR tested and untested, as well as a comparison between vendors.

scholarly journals Preparation of a Ceramic Matrix Composite Made of Hydroxyapatite Nanoparticles and Polylactic Acid by Consolidation of Composite Granules

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1060
Author(s):  
Elzbieta Pietrzykowska ◽  
Barbara Romelczyk-Baishya ◽  
Jacek Wojnarowicz ◽  
Marina Sokolova ◽  
Karol Szlazak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Polylactic Acid ◽  
Matrix Composite ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix ◽  
Hybrid Nanocomposites ◽  
Hydroxyapatite Nanoparticles ◽  
Pressure Infiltration ◽  
Composite Granules

Composites made of a biodegradable polymer, e.g., polylactic acid (PLA) and hydroxyapatite nanoparticles (HAP NPs) are promising orthopedic materials. There is a particular need for biodegradable hybrid nanocomposites with strong mechanical properties. However, obtaining such composites is challenging, since nanoparticles tend to agglomerate, and it is difficult to achieve good bonding between the hydrophilic ceramic and the hydrophobic polymer. This paper describes a two-step technology for obtaining a ceramic matrix composite. The first step is the preparation of composite granules. The granules are obtained by infiltration of porous granules of HAP NPs with PLA through high-pressure infiltration. The homogeneous ceramic-polymer granules are 80 μm in diameter, and the composite granules are 80 wt% HAP NPs. The second step is consolidation of the granules using high pressure. This is performed in three variants: Uniaxial pressing with the pressure of up to 1000 MPa at room temperature, warm isostatic compaction (75 MPa at 155 °C), and a combination of the two methods. The combined methods result in the highest densification (99%) and strongest mechanical properties; the compressive strength is 374 MPa. The structure of the ceramic matrix composite is homogeneous. Good adhesion between the inorganic and the organic component is observable using scanning electron microscopy.

Design of Stress Constrained SiC/SiC Ceramic Matrix Composite Turbine Blades

2020 ◽  
Author(s):  
Robert J. Boyle ◽  
Pritheesh Gnanaselvam ◽  
Ankur H. Parikh ◽  
Ali A. Ameri ◽  
Jeffrey P. Bons ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Turbine Blades ◽  
Ceramic Matrix Composite ◽  
Aircraft Engine ◽  
Stress Constraints ◽  
Time Frame ◽  
Von Mises Stress ◽  
Efficiency Improvement ◽  
Low Aspect Ratio ◽  
Von Mises

Abstract The structural and aerodynamic performance of a a low aspect ratio SiC/SiC CMC High Pressure Turbine blade was determined. The application was a NASA notional single aisle aircraft engine to be available in the N+3, beyond 2030, time frame. The notional rpm was maintained, and to satisfy stress constraints the annulus area was constrained. This led to a low span blade. For a given clearance low span blade are likely to have improved efficiency when shrouded. The efficiency improvement due to shrouding was found to strongly depend on the axial gap between the shroud and casing. Axial gap, unlike clearance or reaction, is not a common parameter used to correlate the efficiency improvement due to shrouding. The zero clearance stage efficiency of the low aspect ratio turbine was 0.920. Structural analyses showed that the rotor blade could be shrouded without excessive stresses. The goal was to have blade stresses less than 100 MPa (14.5 ksi) for the unshrouded blade. Under some not very restrictive circumstances, such as blade stacking, a one-dimensional radial stress equation accurately predicted area averaged Von Mises stress at the blade hub. With appropriate stacking radial and Von Mises stresses were similar.

Design of Stress Constrained SiC/Sic Ceramic Matrix Composite Turbine Blades

2021 ◽  
Author(s):  
Robert Boyle ◽  
Pritheesh Gnanaselvam ◽  
Ankur H. Parikh ◽  
Ali Ameri ◽  
Jeffrey Bons ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Turbine Blades ◽  
Ceramic Matrix Composite ◽  
Aircraft Engine ◽  
Stress Constraints ◽  
Time Frame ◽  
Von Mises Stress ◽  
Efficiency Improvement ◽  
Low Aspect Ratio ◽  
Von Mises

Abstract The structural and aerodynamic performance of a a low aspect ratio SiC/SiC CMC High Pressure Turbine blade was determined. The application was a NASA notional single aisle aircraft engine to be available in the N+3, beyond 2030, time frame. The notional rpm was maintained, and to satisfy stress constraints the annulus area was constrained. This led to a low span blade. For a given clearance low span blade are likely to have improved efficiency when shrouded. The efficiency improvement due to shrouding was found to strongly depend on the axial gap between the shroud and casing. Axial gap, unlike clearance or reaction, is not a common parameter used to correlate the efficiency improvement due to shrouding. The zero clearance stage efficiency of the low aspect ratio turbine was 0.920. Structural analyses showed that the rotor blade could be shrouded without excessive stresses. The goal was to have blade stresses less than 100 MPa(14.5 ksi) for the unshrouded blade. Under some not very restrictive circumstances, such as blade stacking, a one-dimensional radial stress equation accurately predicted area averaged Von Mises stress at the blade hub. With appropriate stacking radial and Von Mises stresses were similar.

Ceramic Matrix Composites for High Pressure Turbine Vanes

2014 ◽  
Author(s):  
Robert J. Boyle ◽  
Ankur H. Parikh ◽  
Vinod K. Nagpal ◽  
Michael C. Halbig ◽  
James A. DiCarlo
Keyword(s):  
High Pressure ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Thermal Loads ◽  
Matrix Composites ◽  
Gas Temperature ◽  
High Pressure Turbine ◽  
Trailing Edge ◽  
Barrier Coating

Through thickness, hoop, and spanwise component stresses were calculated for two Ceramic Matrix Composite (CMC) vane configurations. The analyses are for the first stage vane of a High Pressure Turbine. One configuration is for a vane with trailing edge ejection, and the other has no trailing edge ejection. The effects of analyzing separate pressure and thermal loads, as well as combining these loads, are examined. For the case without trailing edge ejection the effects of variations in the stiffness modulus are given. Results are discussed for the midspan region as well as for the entire span. Pressure loads were determined assuming a mainstream gas and coolant pressure of 50 atm. Thermal loads were determined assuming a gas temperature of 2141°K(3394°F), and a maximum Environmental Barrier Coating temperature of 1756°K(2700°F). The desired maximum CMC temperature was 1589°C(2400°F).

Design of Stress Constrained SiC/SiC Ceramic Matrix Composite Turbine Blades

2021 ◽  
Author(s):  
Robert Boyle ◽  
Pritheesh Gnanaselvam ◽  
Ankur H. Parikh ◽  
Ali Ameri ◽  
Jeffrey Bons ◽  
...  
Keyword(s):  
Matrix Composite ◽  
Turbine Blades ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix ◽  
Sic Ceramic
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