Ceramic Centerbody for Gas Turbine Engine Weight Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft gas turbine engines face challenges in reducing weight while maintaining mechanical properties, corrosion resistance, oxidation resistance, and erosion resistance in the hot section components, particularly in the centerbody region, where metallic materials are heavy and prone to degradation from high temperatures and exhaust gases.
Innovation Solution
A ceramic matrix composite (CMC) centerbody with an interlaced ceramic fiber structure and a ceramic matrix, sintered to withstand high temperatures and erosion, is used, featuring a conical shape with mechanical attachment to the engine frame via Y-brackets to accommodate thermal expansion mismatches and provide additional strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If metallic materials are used for hot section components, then mechanical properties and corrosion resistance are maintained, but weight is excessive
Solution Approach 1:
The patent applies composite materials by using ceramic matrix composite (CMC) consisting of interlaced ceramic fibers embedded in a ceramic matrix. This composite structure provides both the necessary mechanical strength at high temperatures and significant weight reduction compared to traditional metallic materials. The interlaced fiber architecture ensures structural integrity while the ceramic composition resists oxidation and erosion in the harsh hot section environment.
2Weight of moving object
If lighter weight non-metallic materials are used, then weight is reduced, but corrosion and oxidation resistance deteriorate
Solution Approach 1:
The ceramic matrix composite combines lightweight ceramic fibers with a ceramic matrix material that inherently resists corrosion and oxidation. The interlaced fiber structure provides mechanical strength while the ceramic composition maintains reliability in corrosive environments. This composite approach achieves both weight reduction and maintained reliability simultaneously.
Solution Approach 2:
The patent utilizes a porous ceramic matrix structure that provides oxidation resistance. The controlled porosity allows the material to withstand oxidative environments while maintaining structural integrity and lightweight properties. The porous structure is designed to prevent degradation from hot exhaust gases.
3Weight of moving object
If ceramic matrix composite is used, then weight is reduced and oxidation resistance is improved, but erosion resistance must be maintained
Solution Approach 1:
The interlaced ceramic fiber structure within the ceramic matrix provides enhanced erosion resistance. The fiber reinforcement prevents crack propagation and material degradation from hot exhaust gas erosion while maintaining the lightweight advantage of ceramic materials. This composite architecture ensures the centerbody can withstand the harsh erosive environment.
Solution Approach 2:
The patent applies different orientations of ceramic fiber plies in different regions of the centerbody to provide localized erosion resistance where most needed. The fiber orientation is optimized for specific stress and erosion conditions in different areas, ensuring adequate protection while minimizing weight.
4Strength
If ceramic matrix composite with interlaced fiber structure is used, then mechanical integrity at high temperature is maintained, but manufacturing complexity increases
Solution Approach 1:
The patent employs preliminary action by pre-forming the ceramic fiber reinforcement structure before impregnating with matrix material. The fiber preform is carefully constructed with interlaced plies in predetermined orientations to ensure mechanical integrity, then the matrix is added to complete the composite. This sequential approach simplifies the manufacturing of complex composite structures.
Solution Approach 2:
The manufacturing process is divided into separate stages: fiber preform fabrication, matrix impregnation, and sintering. Each stage can be optimized independently, allowing for better control of the complex manufacturing process while ensuring the final product achieves the required mechanical properties at high temperature.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The CMC centerbody achieves a weight reduction of 4-5 pounds compared to metallic components, offers improved corrosion resistance, and maintains mechanical integrity at elevated temperatures, withstanding exhaust temperatures up to 2200°F without oxidation or significant erosion.
Implementation Method 1
The ceramic fiber and matrix are sintered to form a sintered CMC centerbody
Implementation Method 2
Because the centerbody is a ceramic matrix composite material that is sintered, it is not subject to further oxidation
Implementation Method 3
The CMC composite has sufficient thickness so that the hot exhaust gases passing over its exterior surface do not erode the CMC centerbody significantly over the life of the engine
Data Source
AI summary
A ceramic centerbody (120) for an aircraft gas turbine engine. The ceramic centerbody (120) comprises an interlaced fiber structure having fibers oriented in a substantially transverse directions and a ceramic matrix surrounding the ceramic fiber structure. The ceramic fiber and matrix are formed into a conical shape having a fore end (128) and an aft end (126). The centerbody includes a means for mechanical attachment (130) circumferentially oriented around the fore end of the centerbody. The fore end further includes additional plies oriented in a third preselected direction, thereby providing additional strength to for mechanical attachment.