Split Fan Exit Guide Vanes for Airflow Pressure Redistribution

Solution Overview

Problem

Current gas turbine engine designs with non-variable fan exit guide vanes are not optimized for specific mission conditions, leading to inefficiencies and increased fan stress due to fixed installation angles and lack of adjustability.

Innovation Solution

The implementation of split variable fan exit guide vanes with independently adjustable upper and lower sections, actuated by actuators, allows for dynamic adjustment of incidence and installation angles in response to operating conditions, optimizing airflow direction and reducing fan stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If non-variable fan exit guide vanes with fixed installation angles are used, then the structural simplicity and ease of manufacture are maintained, but the fan efficiency and system performance are not optimized for specific mission conditions

Engineering Contradiction:

Improveease of manufactureVSAvoidfan efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The fan exit guide vanes are designed with variable incidence angles that can be adjusted during engine operation. Each vane includes an adjustable section that can rotate about a spanwise axis, allowing the incidence angle to be changed responsive to flight conditions such as Mach number and angle of attack, thereby optimizing fan efficiency for different mission phases

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The installation angle parameter of the fan exit guide vanes is made variable rather than fixed. The incidence angle can be dynamically changed based on operating conditions, allowing the system to adapt to different flight regimes and optimize performance across the entire operating envelope

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If fixed installation angles are used for fan exit guide vanes, then the device complexity is reduced, but the adaptability to different operating conditions deteriorates

Engineering Contradiction:

Improvedevice complexityVSAvoidadaptability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The fan exit guide vanes are designed with variable incidence angles that can be adjusted during engine operation. Each vane includes an adjustable section that can rotate about a spanwise axis, allowing the incidence angle to be changed responsive to flight conditions such as Mach number and angle of attack, thereby optimizing fan efficiency for different mission phases

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The variable incidence angle system is controlled based on feedback from flight condition sensors. The control system monitors parameters such as Mach number and angle of attack, and automatically adjusts the vane incidence angles to optimal values for the current operating conditions, enabling adaptive optimization without excessive complexity

Inventive Principle:

Principle #23Feedback

3Ease of manufacture

If non-variable fan exit guide vanes are used, then the manufacturing cost is reduced, but the residual fan stress and thrust-specific fuel consumption increase

Engineering Contradiction:

Improveease of manufactureVSAvoidthrust-specific fuel consumption

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The fan exit guide vanes are designed with variable incidence angles that can be adjusted during engine operation. Each vane includes an adjustable section that can rotate about a spanwise axis, allowing the incidence angle to be changed responsive to flight conditions such as Mach number and angle of attack, thereby optimizing fan efficiency for different mission phases

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The installation angle parameter of the fan exit guide vanes is made variable rather than fixed. The incidence angle can be dynamically changed based on operating conditions, allowing the system to adapt to different flight regimes and optimize performance across the entire operating envelope

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250376990A1Gas turbine engine with split variable fan exit guide vanes and airflow radial total pressure profile re-distribution

Publication Date: 2025.12.11 RTX CORP

AI summary

A gas turbine engine with split variable fan exit guide vanes including a fan duct supporting a circumferential pattern of split variable fan exit guide vanes, the split variable fan exit guide vanes comprising an upper section and a lower section, the upper section and the lower section each being adjustable about an axis extending along a span of each of the split variable fan exit guide vanes; an upper actuator in operative communication with the upper section, the upper actuator configured to independently adjust an incidence angle of the upper section responsive to predetermined gas turbine operating conditions; and a lower actuator in operative communication with the lower section, the lower actuator configured to independently adjust an incidence angle of the lower section responsive to the predetermined gas turbine operating conditions.