Aircraft Engine Inlet Duct with Flow Relief Pathway
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Solution Overview
Problem
Aircraft engine inlet ducts experience significant pressure and flow distortion, particularly at yaw angles and during reverse flight, due to the bifurcated configuration, leading to performance issues.
Innovation Solution
Inlet ducts with two or more converging legs and a flow relief pathway or bypass leg to balance airflow and equalize pressure distribution, reducing distortion and stabilizing airflow to the engine inlet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a bifurcated inlet duct configuration is used, then the engine can be positioned with inlet openings at lateral sides of the airframe, but significant pressure and flow distortion occurs at yaw angles
Solution Approach 1:
A flow relief pathway is introduced as an intermediary element between the two inlet duct legs. This pathway acts as a mediator that redistributes airflow from the high-pressure leg to the low-pressure leg, equalizing pressure distribution and reducing flow distortion at the engine inlet while maintaining the bifurcated configuration's positioning flexibility
Solution Approach 2:
The invention changes the flow parameters (pressure and velocity distribution) within the inlet duct system by introducing the flow relief pathway. This modifies the airflow characteristics to achieve more uniform pressure distribution across the engine inlet, transforming the distorted flow field into a more uniform one
2Adaptability or versatility
If a bifurcated inlet duct is used for reverse flight operations, then the aircraft can perform reverse flight, but significant engine inlet pressure and flow distortion occurs
Solution Approach 1:
The flow relief pathway serves as a compensatory mechanism during reverse flight operations. It redistributes the uneven airflow caused by the bifurcated configuration, ensuring more uniform pressure distribution at the engine inlet and maintaining reliable engine performance during reverse flight
3Stress or pressure
If ram pressure effects increase pressure in one duct leg, then that leg experiences higher pressure, but the other leg experiences significantly less pressure causing flow distortion
Solution Approach 1:
The flow relief pathway acts as a pressure equalization mechanism. It allows airflow to move from the high-pressure leg (exposed to ram pressure) to the low-pressure leg (in flow shadow), thereby equalizing pressure distribution between the two legs and reducing flow distortion at the engine inlet
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 engine inlet distortion and stabilizes airflow, improving engine performance by equalizing pressure and managing excess airflow, thereby minimizing drag and maintaining optimal engine operation across various flight conditions.
Implementation Method 1
flow relief pathway located at each inlet duct leg to balance airflow from the inlet duct legs to reduce distortion at the engine interface
Implementation Method 2
A portion of the inlet airflow is flowed from at least one inlet duct leg of the two or more inlet duct legs into a flow relief pathway
Implementation Method 3
a bypass leg extending from an inlet duct leg of the one or more inlet duct legs through a bypass opening
Implementation Method 4
bypass leg extending from an inlet duct leg of the one or more inlet duct legs through a bypass opening in the fuselage
Data Source
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AI summary
An inlet duct for an engine or multiple engines includes two or more joining duct legs and a pressure relief pathway located at each duct leg to condition inlet airflow from the duct legs. A method of operating an aircraft includes urging an inlet airflow into two or more duct openings disposed at a fuselage of the aircraft. The inlet airflow is urged through two or more converging inlet duct legs extending from the two or more duct openings toward an engine inlet. A portion of the inlet airflow is flowed from at least one inlet duct leg of the two or more inlet duct legs into a pressure relief pathway. An inlet duct for an engine or multiple engines includes one or more inlet duct legs and a bypass leg extending from an inlet duct leg of the one or more inlet duct legs through a bypass opening.