Cascade Thrust Reverser Radial Expansion Nacelle Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current thrust reverser systems in turbofan engines are bulky, increasing engine size and weight, and face challenges in reducing drag and improving efficiency, particularly as fan sizes increase, necessitating a more compact and lightweight solution.
Innovation Solution
A cascade thrust reverser assembly that expands radially when deployed, allowing for a more compact nacelle design by incorporating a cascade assembly with movable cascade members that increase their radial extent, enabling effective thrust reversal while reducing overall engine dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional thrust reverser systems are used, then thrust reversal function is achieved, but engine size and weight increase
Solution Approach 1:
The cascade members are nested within the nacelle structure when in the retracted position, with each cascade member positioned inside the volume defined by the previous member. This nesting arrangement allows the thrust reverser system to be contained within the existing nacelle envelope, achieving thrust reversal functionality without increasing overall engine weight.
Solution Approach 2:
The cascade members are designed to be movable between a retracted position (normal operation) and a deployed position (thrust reversal). This dynamic configuration allows the system to transition from a compact state that minimizes weight and drag during flight to an extended state that provides effective thrust reversal when needed.
2Reliability
If traditional thrust reverser systems are used, then thrust reversal function is achieved, but nacelle length increases
Solution Approach 1:
Instead of extending the nacelle axially to accommodate thrust reverser components, the cascade members are arranged to expand radially outward from the engine core. This dimensional change allows the thrust reversal functionality to be achieved without increasing the axial length of the nacelle, maintaining a compact overall engine configuration.
3Productivity
If fan size is increased to improve propulsive efficiency, then propulsive efficiency is improved, but nacelle thickness must be reduced to reduce drag
Solution Approach 1:
The cascade members are designed with varying geometries and positions along their length, with each section having optimized local characteristics for its specific function. This allows the thrust reverser system to be integrated into the nacelle without requiring uniform reduction of nacelle thickness, enabling large fan sizes for improved propulsive efficiency while maintaining acceptable drag characteristics.
Data Source
AI summary
A cascade thrust reverser assembly is provided for a turbofan engine. The turbofan engine includes a nacelle assembly defining a bypass passage, and the cascade thrust reverser assembly includes at least one cascade assembly configured to be at least partially enclosed by the nacelle assembly. The cascade assembly may further include a plurality of cascade segments and an actuation assembly operably connected to the plurality of cascade segments, wherein the actuation assembly is configured to increase an axial extent of the cascade assembly and rotate the plurality of cascade segments.