Wide Fuselage Aircraft Boundary Layer Ingestion Duct
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Solution Overview
Problem
Aircraft with wide fuselages experience increased boundary layer drag, and existing methods to ingest boundary layer air into gas turbine engines in the tail only partially address aerodynamic improvements.
Innovation Solution
A selectively moveable duct system that allows or blocks airflow to the fan rotor of the gas turbine engine, driven by a motor and control system, to optimize airflow from both the upper and lower surfaces of the fuselage, reducing drag by pivoting about pivot axes and utilizing a mechanical connection for single-drive operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a wide fuselage is used to increase aircraft capacity, then passenger capacity and cargo space are improved, but boundary layer drag increases
Solution Approach 1:
The patent converts the harmful boundary layer air, which normally increases drag, into a beneficial resource by directing it into the gas turbine engine's fan rotor. The wide fuselage's upper surface boundary layer air is captured through specially positioned inlets and ducts, transforming this drag-inducing flow into useful airflow that contributes to engine thrust, thereby eliminating the drag penalty while maintaining the wide fuselage configuration for increased capacity
2Object-affected harmful factors
If boundary layer air is ingested into the gas turbine engine, then drag is reduced, but airflow control and engine performance may be compromised
Solution Approach 1:
The patent employs dynamically adjustable ducts with movable walls that can change their configuration based on flight conditions. These ducts are equipped with actuators that allow them to open or close, adjusting the amount of boundary layer air ingested into the engine. This dynamic control system enables the aircraft to optimize drag reduction during cruise while maintaining proper airflow control during takeoff, landing, and other critical phases where boundary layer ingestion might be detrimental
Solution Approach 2:
The system changes the parameter of airflow quantity by using movable duct walls that can adjust the cross-sectional area through which boundary layer air enters the engine. By varying this geometric parameter, the system controls the mass flow rate of boundary layer air into the engine, allowing optimization of drag reduction benefits while preventing performance degradation under different operating conditions
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 duct system effectively reduces drag by allowing boundary layer air from both surfaces to be ingested into the engine, improving aerodynamics and maintaining functionality during takeoff and cruise conditions.
Implementation Method 1
there is an increased boundary layer drag
Implementation Method 2
This decreases the drag from the upper boundary layer
Data Source
AI summary
An arrangement for reducing drag on the body of an aircraft with a relatively wide fuselage comprises a gas turbine engine. At least one duct is selectively moveable between a closed position and an open position, such that the at least one duct allows airflow to move toward a fan rotor in the gas turbine engine in the open position, but blocks airflow when in the closed position. An aircraft body is also disclosed.