Airfoil Trailing-Edge Injection for Flow Separation Control
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Solution Overview
Problem
Conventional airfoils, compressor blades, and turbine blades face efficiency reduction and potential catastrophic failure due to flow separation near the trailing edge during different flight regimes, which existing technologies have not adequately addressed.
Innovation Solution
A system and method that injects fluid or gas through a porous membrane and capillary tubes into the separated boundary layer near the trailing edge of the airfoil to reduce or eliminate flow separation, utilizing a flow control device that channels air or fluid over the upper surface and includes a pump and sensor for regulating the flow rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional airfoil design is used, then the structure is simple and reliable, but flow separation occurs near the trailing edge during different flight regimes, reducing efficiency
Solution Approach 1:
The patent employs a porous membrane at the trailing edge of the airfoil that allows fluid injection into the boundary layer. The porous structure enables controlled injection of fluid or gas through its walls, directly addressing flow separation while maintaining a relatively simple overall airfoil structure. This resolves the contradiction by providing flow separation control without requiring complex mechanical moving parts.
Solution Approach 2:
The patent uses pneumatic injection of fluid or gas through the porous membrane into the separated boundary layer. This hydraulic/pneumatic approach allows active control of flow separation by injecting momentum into the boundary layer, improving airfoil efficiency across different flight regimes without mechanical complexity.
2Reliability
If flow separation control is implemented using fluid injection, then boundary layer separation is reduced or eliminated, but the device complexity increases due to additional components
Solution Approach 1:
The porous membrane serves as both a structural component and a fluid injection mechanism. Its porous walls naturally facilitate fluid injection into the boundary layer without requiring separate injection nozzles or complex valve systems, thereby improving flow separation control reliability while minimizing device complexity.
Solution Approach 2:
The porous membrane performs multiple functions: it serves as a structural element of the airfoil, a fluid distribution system, and an injection mechanism. This multi-functionality reduces the need for additional dedicated components, maintaining reliability while controlling device complexity.
3Productivity
If fluid injection is used to control flow separation, then airfoil efficiency is improved across flight regimes, but energy consumption increases due to pump operation
Solution Approach 1:
The system is designed to utilize the aircraft's existing engine exhaust or onboard fluid systems for injection, rather than requiring dedicated high-energy pumps. The porous membrane passively distributes the fluid, and the injection leverages existing pressure differentials, reducing additional energy consumption while maintaining airfoil efficiency improvements.
Solution Approach 2:
The system allows dynamic adjustment of injection parameters (flow rate, pressure, timing) to optimize performance across different flight regimes. By adjusting these parameters, the system maintains high airfoil efficiency while minimizing energy consumption, particularly by reducing or stopping injection when flow separation is not present.
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 or eliminates boundary layer separation, enhancing the airfoil's efficiency and performance across various flight regimes by reattaching the separated boundary layer, thereby preventing catastrophic failures.
Implementation Method 1
A system and method that injects fluid or gas through a porous membrane and capillary tubes into the separated boundary layer
Implementation Method 2
utilizing a flow control device that channels air or fluid over the upper surface and includes a pump and sensor for regulating the flow rate
Implementation Method 3
includes a pump and sensor for regulating the flow rate
Data Source
AI summary
A combination of an airfoil, turbine blade, or compressor blade with a flow separation control device includes an airfoil, a flow separation control device, and an injection system. The airfoil includes a body with an upper surface and a lower surface that extend from a leading edge to a trailing edge. The flow separation control device includes a plurality of openings on the upper surface of the body. The injection system includes an inlet tube, a pump in gaseous communication with the inlet tube, and a flow regulator in gaseous communication with the pump and the plurality of capillary tube.