Crescent Vortex Generator Array for High-Angle-of-Attack Lift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aerohydrodynamic surfaces face challenges in maintaining efficient vortex generation at subcritical angles of attack, leading to reduced lift and increased drag, and are prone to boundary layer separation, which affects stability and controllability, especially at high angles of attack.
Innovation Solution
The design incorporates an array of vortex generators with crescent-shaped working edges positioned near the leading edge to generate counter-rotating vortex structures, optimizing their placement and configuration to maintain boundary layer energy and reduce parasitic vortex generation, allowing for smoother transition through stall regimes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If vortex generators are mounted on the upper surface of the wing near the leading edge, then boundary layer energy is increased and lift is improved, but profile drag increases and the lift-to-drag ratio deteriorates at high angles of attack
Solution Approach 1:
The vortex generator array is divided into multiple overlays, each with specific working edges positioned at different locations and angles. This segmentation allows different portions of the vortex generators to serve different functions: some edges generate beneficial counter-rotating vortices to increase boundary layer energy, while others are positioned to minimize parasitic vortex generation and drag.
Solution Approach 2:
The working edges of the vortex generators are configured with specific local properties: adjacent working edges are positioned at angles of 20-60 degrees to generate counter-rotating vortices in specific regions, while other edges are positioned to minimize harmful vortex generation. This local optimization of vortex generation characteristics improves the overall lift-to-drag ratio by enhancing beneficial effects while reducing parasitic losses.
2Reliability
If vortex generators are positioned to generate strong vortex structures, then boundary layer separation is delayed, but parasitic vortex generation increases and efficiency decreases
Solution Approach 1:
The vortex generators utilize asymmetric positioning of working edges with different orientation angles (20-60 degrees between adjacent edges). This asymmetric configuration creates a controlled pattern of counter-rotating vortices that effectively delay boundary layer separation while the asymmetric arrangement also helps cancel out parasitic vortex generation through destructive interference of harmful vortex structures.
Solution Approach 2:
Instead of attempting to eliminate all vortex generation, the invention inverts the approach by deliberately generating counter-rotating vortices that interfere destructively with parasitic vortices. The harmful parasitic vortices are not prevented from forming, but their negative effects are canceled by the opposing rotation of deliberately generated vortex structures from the working edges.
3Force
If the angle of attack is increased to improve lift, then vortex generation power decreases due to boundary layer instability, but lift can be maintained
Solution Approach 1:
The vortex generators are positioned near the leading edge of the wing, performing preliminary action on the boundary layer before it becomes unstable at higher angles of attack. By injecting vortex energy early in the flow path, the boundary layer is energized in advance, maintaining attachment and preventing separation even when the angle of attack increases and natural vortex generation would otherwise diminish.
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 configuration enhances lift characteristics, delays boundary layer separation, and improves stability and controllability at high angles of attack, reducing profile drag and increasing the critical angle of attack, while maintaining efficiency at low angles.
Implementation Method 1
the array of vortex generators includes three or more pairs of working edges, wherein the tangents to the midpoints of the frontal projections of the paired working edges are located at an angle of 20 to 60° to each other... so as to be able to generate counter-rotating vortex structures
Data Source
AI summary
This relates to the field of aerohydrodynamics and can be used on wings and control surfaces of aircraft, controlled spoilers of sports cars, all-movable masts and sails of sailing yachts and sailboards, as well as on blades and vanes of various bladed machines. An aerohydrodynamic surface includes an array of vortex generators and a main part. The main part comprises two sides mating with each other to form a leading and a trailing edges. The array of vortex generators includes elevations with crescent-shaped working edges located near the leading edge. The elevations and the working edges are configured to generate counter-rotating vortex structures. An array of vortex generators and a method of mounting the same onto the aerohydrodynamic surface are also described. The invention makes it possible to improve the properties of the aerohydrodynamic surfaces at high angles of attack.