Aircraft Thrust Reverser Cascade Integration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing aircraft gas turbine thrust reverser systems are characterized by high weight, complex control requirements, and inefficiency due to separate drives for the rear panel and cascade elements, leading to increased noise and longer engine cowling lengths.

Innovation Solution

Integration of cascade elements directly with the rear panel, where the rear panel's displacement simultaneously moves the cascade elements, eliminating the need for additional drives and incorporating flow guide vanes with specific curvatures to optimize airflow, reducing weight and complexity while maintaining functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate drives are used for the rear panel and cascade elements, then the thrust reverser can be controlled in stages, but the device complexity and weight increase significantly

Engineering Contradiction:
Improvestaged control capabilityVSAvoiddrive system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The cascade elements are integrated directly with the rear panel, forming a unified structure where the rear panel serves as both the blocking element and the mounting structure for cascade elements. This eliminates the need for separate drives, reducing device complexity while maintaining staged control capability through the single drive's ability to position the integrated structure at different stages.

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If fixed cascade elements are fully accommodated in the engine cowl in cruising configuration, then the structure is simplified, but the overall length of the engine cowl increases

Engineering Contradiction:
Improvestructural simplicityVSAvoidengine cowl length
Core Design Contradiction:
Device complexityVSLength of stationary object

Solution Approach 1:

The cascade elements are nested within the engine cowl structure during cruising configuration, positioned within the annular space between the core engine casing and the outer fairing. When thrust reversal is required, the integrated rear panel with cascade elements displaces axially to deploy the cascade elements into the thrust reverser opening, effectively hiding the extended length within the cowl's internal volume during normal operation.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If the rear panel is partially displaced to adjust outlet nozzle cross-section, then fan vibrations are reduced, but the thrust reverser efficiency decreases due to sharp edge flow deflection

Engineering Contradiction:
Improvefan operation stabilityVSAvoidthrust reverser efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The rear panel is designed with a rounded outer front edge instead of a sharp edge. The cascade elements mounted on this rounded surface feature flow guide vanes with curvatures adapted to the rounded edge geometry. This curved configuration enables smooth flow deflection that maintains thrust reverser efficiency while allowing the rear panel to be partially displaced for fan vibration control.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

This solution simplifies the construction, reduces weight, and enhances efficiency by using a single drive system, improving airflow deflection and reducing noise, resulting in a more reliable and efficient thrust reverser system.

Implementation Method 1

at least one flow guide vane is arranged behind the flow guide element, which has an opposite curvature relative to the thrust reverser guide vanes. This curvature is designed in such a way that a partial flow emerging from the bypass duct through an outflow gap is deflected and guided along the surface of the rear paneling in a flow-optimized manner.

Methodology Applied
Scientific EffectFlow guidance:

Data Source

PatentEP3059431B1Aircraft engine cowl of a gas turbine with thrust reverser and variable area fan nozzle
Publication Date: 2019.05.01 ROLLS ROYCE DEUT LTD & CO KG
  • EP3059431B1 patent drawingFigure 1
  • EP3059431B1 patent drawingFigure 2
  • EP3059431B1 patent drawingFigure 3

AI summary

The invention relates to an engine cowling of an aircraft gas turbine engine with a thrust reverser device, a core engine 10 and a bypass channel 31 surrounding it, a front cowling 29 enclosing the bypass channel 31, a rear cowling 30 axially displaceable, and cascade elements 32 arranged around the circumference, which can be inserted into a gap resulting from a displacement of the rear cowling 30 relative to the front cowling 29 by a substantially axial displacement, wherein the cascade elements 32 are directly connected to the rear cowling 30, the rear cowling 30 has a rounded outer leading edge 33, and the cascade element 32 has a flow guide element 34 at its rear region, in front of which several thrust reverser guide vanes 35 are arranged and behind which at least one flow guide vane 36 is arranged.whose curvature resembles the rounding of the outer front edge 33 of the rear fairing 30.