Jet Nozzle Area Control Using Inflatable Diaphragm Panels
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Solution Overview
Problem
Existing jet nozzle effective area adjustment mechanisms in gas turbine engines are bulky, heavy, and expensive due to the use of multiple actuators, segmented panels, and mechanical arms, which increase the size and weight of the engine.
Innovation Solution
The implementation of a jet nozzle effective area control system utilizing inflatable diaphragms and split duct panels with actuators, such as LVDT actuators, to adjust the effective area of the jet nozzle, reducing mechanical complexity and weight by using fluid pressure modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple actuators, segmented panels, and mechanical arms are used to adjust jet nozzle effective area, then the adjustment mechanism can achieve precise control, but the size, weight, and expense of the engine increase
Solution Approach 1:
The patent combines multiple separate adjustment mechanisms (actuators, segmented panels, mechanical arms) into a single integrated inflatable diaphragm system. The diaphragm integrates the functions of multiple actuators and mechanical components into one unified structure that can adjust the jet nozzle effective area without requiring separate mechanical arms or segmented panels, thereby reducing overall weight while maintaining control capability
Solution Approach 2:
The patent replaces traditional mechanical adjustment systems (mechanical arms, pivot joints, segmented panels) with a pneumatic system using an inflatable diaphragm. Instead of using mechanical forces and moving parts to adjust the nozzle area, the system uses air pressure to inflate or deflate the diaphragm, which smoothly changes the nozzle effective area without mechanical contact or complex linkages, significantly reducing weight and complexity
2Ease of operation
If multiple actuators and mechanical components are used for jet nozzle adjustment, then the control functionality is achieved, but the device complexity and expense increase
Solution Approach 1:
The patent merges multiple separate control components into a single integrated diaphragm system. The diaphragm combines the functions of multiple actuators, mechanical arms, and pivot joints into one unified pneumatic structure, eliminating the need for complex mechanical linkages and reducing the overall number of parts while maintaining full control functionality
Solution Approach 2:
The patent substitutes complex mechanical adjustment systems with a simple pneumatic inflation/deflation mechanism. Instead of coordinating multiple actuators and mechanical components, the system uses a single pneumatic pressure control to adjust the diaphragm volume, which automatically changes the nozzle effective area through fluid pressure, dramatically simplifying the device architecture
3Reliability
If traditional mechanical adjustment mechanisms are used, then structural strength and reliability are maintained, but the weight and size of the engine increase
Solution Approach 1:
The patent replaces weight-heavy mechanical adjustment mechanisms with a lightweight pneumatic system. The inflatable diaphragm uses air pressure to generate the necessary structural force to adjust the nozzle area, eliminating the need for heavy mechanical arms, actuators, and support structures while maintaining the reliability of the adjustment function through pneumatic pressure control
Solution Approach 2:
The patent employs an inflatable diaphragm made of flexible material that can withstand operational pressures and temperatures. This thin-film structure replaces bulky mechanical components with a lightweight flexible shell that maintains structural integrity through pneumatic pressure, providing reliable adjustment capability with minimal weight penalty
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 system provides efficient and lightweight adjustment of the jet nozzle effective area, enhancing engine performance and efficiency by modulating the diaphragm inflation level during different operating conditions, while also integrating with thrust reverser functions without additional mechanisms.
Implementation Method 1
utilizing inflatable diaphragms and split duct panels with actuators, such as LVDT actuators, to adjust the effective area of the jet nozzle, reducing mechanical complexity and weight by using fluid pressure modulation
Data Source
AI summary
An aircraft gas turbine engine includes a fan that in operation moves air through both a core airflow path and a bypass airflow path of the gas turbine engine. The core airflow path and the bypass airflow path converge at a jet nozzle of the gas turbine engine. A method of controlling the gas turbine engine includes detecting, at a controller of the gas turbine engine, a cruise operating condition of the gas turbine engine, and in response to detecting the cruise operating condition, repositioning a plurality of overlap jointed split duct panels such that an effective area of the jet nozzle is reduced.