Removable Airflow Oscillator Inserts for Boundary Layer Control
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Solution Overview
Problem
Existing airflow oscillation devices integrated into aircraft airframes are heavy, difficult to maintain, and prone to clogging, which reduces hover performance due to airflow separation and drag issues.
Innovation Solution
A removable passive airflow oscillation device is integrated into a pressurized wing structure, using a self-contained design with an ingress and egress opening to generate oscillating airflow, allowing for quick replacement and maintenance, and can be 3-D printed with high-temperature materials like Polyetherimide or made of metal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large aluminum block with multiple actuators is used, then airflow control capability is improved, but device weight increases and maintenance difficulty increases
Solution Approach 1:
The patent divides the airflow control system into multiple independent oscillation devices that can be separately installed and removed. Each device contains its own actuator(s), eliminating the need for a large integrated aluminum block. This segmentation reduces overall weight while maintaining airflow control capability through distributed devices.
Solution Approach 2:
The patent extracts the actuator from the solid aluminum block structure and integrates it directly into the oscillation device housing. This allows the actuator to be easily removed and replaced without removing the entire aluminum block, reducing maintenance complexity and device weight.
2Strength
If actuators are built into a large aluminum block, then structural integrity is improved, but ease of repair and maintenance deteriorates
Solution Approach 1:
The oscillation device is segmented into removable components including the actuator, oscillation geometry, and housing. This allows individual actuators to be accessed, removed, and replaced without affecting the structural integrity of the airframe or requiring replacement of the entire assembly.
Solution Approach 2:
The patent implements a dynamic maintenance system where actuators can be quickly swapped during operation. The oscillation device design allows for rapid actuator replacement while maintaining structural integrity through standardized mounting interfaces and sealed configurations.
3Reliability
If multiple actuators are integrated into a block, then airflow control effectiveness is improved, but device complexity for cleaning and inspection increases
Solution Approach 1:
The patent segments the airflow control system into individual oscillation devices with external access points. Each device can be independently inspected and cleaned through accessible openings, eliminating the need to disassemble a large integrated block to reach internal actuators.
Solution Approach 2:
The oscillation device housing serves as an intermediary structure that provides protected yet accessible containment for the actuators. It allows airflow control effectiveness while maintaining ease of inspection through external access points and removable components.
4Reliability
If wing flaps are rotated down to minimize download effects, then hover performance is improved, but airflow separation increases causing drag
Solution Approach 1:
The patent employs oscillating airflow generated by fluidic actuators to prevent boundary layer separation on the wing flaps. The high-frequency oscillations energize the boundary layer, keeping it attached to the flap surface even when flaps are in the down position, thereby reducing drag while maintaining hover performance.
Solution Approach 2:
The patent replaces traditional mechanical flap control systems with fluidic oscillation devices that use compressed air to generate oscillating flow fields. This substitution eliminates the need for complex mechanical actuation while achieving superior airflow control 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
This solution reduces aircraft weight, enhances hover performance by keeping airflow attached, and simplifies maintenance by allowing individual device replacement, increasing reliability and reducing drag.
Implementation Method 1
a cavity configured to receive the airflow from an ingress opening, direct the airflow therethrough to generate a predetermined oscillating airflow
Implementation Method 2
The aft chamber of the flap seal can be sealed and pressurized to serve as a plenum providing the airflow to the actuators
Implementation Method 3
AFC actuators can control airflow mixing and energize the boundary layer to control flow separation
Data Source
AI summary
A removable passive airflow oscillation device can be disposed within a pressurized wing structure utilized as a plenum. The passive airflow oscillation device can be a removable insert disposed into exterior vehicle surfaces with pressurization of a sealed chamber to provide the airflow. The device can include a cavity configured to receive the airflow from an ingress opening, direct the airflow therethrough to generate a predetermined oscillating airflow, and expel the oscillatory airflow from the egress opening. The removable passive airflow oscillation devices can provide quick and simple replacement and maintenance of damaged or clogged devices. The aft chamber of the flap seal can be sealed and pressurized to serve as a plenum providing the airflow to the actuators. The device can receive airflow, such as compressor air, and expel an oscillating airflow. Because each device is self-contained the number of devices and location thereof can vary by application.