Deployable Propulsor Assembly Boundary Layer Ingestion
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Solution Overview
Problem
Conventional commercial aircraft propulsion systems face challenges in reducing drag and enhancing propulsion efficiency, particularly due to the interaction between turbofan jet engines and the aircraft's fuselage and wings, which affects net propulsive thrust.
Innovation Solution
The integration of a deployable assembly with a propulsor mounted at the aft end of the fuselage, featuring a movable nacelle and panels that alter airflow into or through the propulsor inlet, allowing for the ingestion and re-energization of boundary layer airflow, thereby reducing drag and improving propulsion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a propulsor is mounted at the aft end of the fuselage to ingest boundary layer airflow, then propulsion efficiency is improved, but drag increases due to the presence of the propulsor structure
Solution Approach 1:
The patent employs a deployable assembly that can transition between extended and retracted positions. When extended, the assembly captures boundary layer airflow for the propulsor; when retracted, it minimizes drag. This dynamic configuration allows the system to adapt its structure based on operational requirements, resolving the contradiction between propulsion efficiency improvement and drag reduction.
2Productivity
If the deployable assembly is extended to capture boundary layer airflow, then propulsion efficiency improves, but the device complexity increases
Solution Approach 1:
The deployable assembly is divided into multiple panels or segments that can independently move between extended and retracted positions. This segmentation simplifies the overall structure by allowing each panel to be controlled separately, reducing the complexity of the actuation mechanism while still achieving the desired airflow capture function.
3Force
If the propulsor ingests boundary layer airflow from the fuselage, then net propulsive thrust increases, but the airflow turbulence increases
Solution Approach 1:
The deployable assembly acts as an intermediary structure between the fuselage boundary layer and the propulsor inlet. It captures the boundary layer airflow and directs it toward the propulsor in a controlled manner, reducing turbulence while maintaining the thrust benefits. The assembly serves as a transition zone that mediates the interaction between the fuselage flow and the propulsor ingestion requirements.
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 enhances propulsion efficiency by altering airflow dynamics, particularly during specific flight operations, thereby improving the overall performance of the aircraft.
Implementation Method 1
the propulsor configured to ingest and re-energize a boundary layer airflow over the fuselage of the aircraft
Implementation Method 2
a propulsor for an aircraft that energizes the wake and improves propulsion efficiency
Data Source
AI summary
An aircraft includes a fuselage extending between a forward end and an aft end; a propulsor mounted to the fuselage at the aft end of the fuselage, the propulsor comprising an outer nacelle, the outer nacelle defining an inlet to the propulsor; and a deployable assembly attached to at least one of the fuselage or the outer nacelle and moveable between a stowed position and an engaged position. The deployable assembly alters an airflow towards the propulsor or into the propulsor through the inlet defined by the outer nacelle when in the engaged position. The propulsor further comprises a tail cone, wherein the outer nacelle defines an exhaust with the tail cone, and wherein the plurality of nacelle panels are movable generally along the axial centerline to a position at least partially aft of the exhaust of the outer nacelle when in the engaged position.