Elastically Deformable Turbojet Air Inlet Lip for Thrust Reversal
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Solution Overview
Problem
High-bypass ratio turbojet engines face performance reduction during thrust reversal due to local depression zones at the air inlet lip, which hinder efficient reverse air flow separation and increase drag, making conventional thrust reversal systems undesirable.
Innovation Solution
An elastically deformable air inlet lip with a controllable movement member that changes from an aerodynamic profile during thrust to an irregular profile during thrust reversal, allowing optimal separation of the reverse air flow and reducing local depressions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional thrust reversal system is integrated into a high-bypass ratio turbojet nacelle, then thrust reversal capability is achieved, but mass, bulk and drag are significantly increased
Solution Approach 1:
The air inlet lip is made elastically deformable to dynamically change its profile between aerodynamic (thrust phase) and irregular (thrust reversal phase), allowing the system to adapt to different operating conditions without adding heavy mechanical thrust reversal equipment
Solution Approach 2:
The physical state of the air inlet lip is changed from rigid to elastically deformable, enabling it to change its geometric parameters (profile shape) in response to different operational phases, thereby achieving thrust reversal capability without conventional heavy systems
2Productivity
If the air inlet lip maintains a fixed aerodynamic profile, then thrust phase performance is optimized, but thrust reversal performance is reduced due to local depression zones
Solution Approach 1:
The air inlet lip transitions from a static aerodynamic profile to a dynamic profile that can elastically deform into an irregular shape during thrust reversal, eliminating local depression zones and improving reverse air flow separation while maintaining thrust phase efficiency
Solution Approach 2:
Different regions of the air inlet lip are designed with different functional characteristics - the elastically deformable portion creates local irregularities during thrust reversal to improve flow separation, while maintaining overall aerodynamic integrity during thrust phase
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
Enhances thrust reversal performance by ensuring efficient separation of the reverse air flow without affecting regular thrust phase efficiency, reducing weight and drag, and eliminating the need for heavy thrust reversal systems.
Implementation Method 1
the air inlet lip comprising at least one elastically deformable portion (230)
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Method for using an air intake (2) of a turbojet engine (1) nacelle comprising at least one elastically deformable portion (230), at least one connecting member (3) mounted in an annular cavity (20) integrally with the elastically deformable portion (230), and at least one controllable displacement member (9), in which method: during a thrust phase of the turbojet engine (1), the controllable displacement member (9) moves the connecting member (3) into a first position (A) in which the elastically deformable portion (230) of the air intake lip (23) has an aerodynamic profile, and during a thrust reversal phase of the turbojet engine (1) the controllable displacement member (9) moves the connecting member (3) into a second position in which the elastically deformable portion (230) of the air intake lip (23) has an irregular profile so as to allow a release (D) of the reverse air flow from the elastically deformable portion (230).