Aircraft Aft Fan Stabilizer Assembly for Boundary Layer Ingestion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional aircraft propulsion systems face inefficiencies due to drag caused by fuselage boundary layers, which are not effectively managed by existing boundary layer ingestion systems, leading to reduced propulsive thrust and increased drag.
Innovation Solution
An aft fan propulsion system with a stabilizer assembly featuring horizontally mounted stabilizers at a downward angle to direct airflow upwards into the fan, reducing drag and enhancing propulsive efficiency by incorporating a boundary layer ingestion design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If boundary layer ingestion systems route slow moving boundary layer air into turbofan jet engines, then drag is reduced by reenergizing the boundary layer airflow, but the relatively slow moving flow with non-uniform velocity profile causes efficiency loss in the engines
Solution Approach 1:
The stabilizer assembly is divided into an inner portion and an outer portion with different functions. The inner portion directs airflow upward at a downward angle to the central axis, while the outer portion provides structural support and stability, allowing each segment to optimize its specific function in managing boundary layer airflow
Solution Approach 2:
The stabilizer assembly introduces a vertical dimension to airflow management by directing boundary layer air upward at a predetermined downward angle. This three-dimensional airflow redirection transforms the horizontal boundary layer flow into a vertical upward flow that enters the aft fan, adding a new spatial dimension to the boundary layer ingestion process
2Stability of the object's composition
If horizontal stabilizers are mounted between the fuselage and the aft fan to stabilize the fan, then fan stability is improved, but a boundary layer develops at the bottom of the fuselage creating low-momentum air that increases drag over the nacelle
Solution Approach 1:
The stabilizer assembly merges the fan stabilization function with the boundary layer ingestion function into a single integrated structure. The same stabilizer that provides fan stability also serves as the airflow directing surface that captures and redirects boundary layer air upward into the fan, eliminating the need for separate components
Solution Approach 2:
The stabilizer assembly performs multiple functions simultaneously: it stabilizes the aft fan during operation, directs boundary layer airflow upward at the predetermined downward angle, and reduces drag by preventing low-momentum air from accumulating over the nacelle. This multi-functional design optimizes both stability and drag reduction
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 solution effectively reduces drag and improves propulsive efficiency by reenergizing boundary layer airflow, directing low-momentum air from the fuselage into the aft fan, thereby enhancing the overall thrust of the aircraft.
Implementation Method 1
An electrically-driven aft fan on the aircraft empennage to derive propulsive benefit by ingesting fuselage boundary layers
Data Source
AI summary
An aerodynamic stabilizer assembly for stabilizing an aft fan mounted to a fuselage of an aircraft is presented. The stabilizer assembly includes one or more generally horizontal stabilizers for mounting to a nacelle of the aft fan and the fuselage so as to stabilize the aft fan. Each of the generally horizontal stabilizers includes an inner portion and an outer portion. The inner portions are mounted to a nacelle of the aft fan and the fuselage at a predetermined downward angle with respect to a central axis of the aft fan so as to direct airflow upwards and into the aft fan, the outer portion being mounted to the inner portion.