Plasma Vortex Generators for Active Flow Control
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Solution Overview
Problem
Existing vortex generator systems, such as passive delta-shaped tabs, are always deployed and add parasitic drag, reducing the efficiency of air vehicles, as they do not have the ability to be selectively activated when needed to prevent airflow separation.
Innovation Solution
The use of plasma streamwise vortex generators (PSVGs) with exposed and covered electrodes and a dielectric layer, which can be selectively activated by an AC voltage source to generate plasma and control airflow, reducing drag only when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive vortex generators are deployed to maintain attached flow, then flow separation is prevented, but parasitic drag increases and efficiency decreases
Solution Approach 1:
The patent transforms passive vortex generators into active plasma-based devices that can be dynamically controlled. Plasma streamwise vortex generators (PSVGs) use dielectric barriers and AC voltage sources to generate plasma only when flow separation is detected, allowing the system to adapt between passive and active states based on operational conditions, thereby reducing parasitic drag during normal operation while maintaining flow attachment when needed.
Solution Approach 2:
The invention changes the operational state of vortex generators from permanently deployed to selectively activated. By using plasma generation controlled by AC voltage sources and dielectric barriers, the system can switch between non-active and active states, changing the parameter of device deployment from static to dynamic, thus eliminating continuous parasitic drag while maintaining the ability to prevent flow separation when required.
2Reliability
If passive vortex generators are always deployed to prevent flow separation, then flow control is reliable, but device complexity increases due to lack of selective activation capability
Solution Approach 1:
The patent replaces mechanical deployment systems with plasma-based actuation. Instead of mechanically moving or deploying physical vortex generator elements, the system uses electrical fields to generate plasma that creates the desired flow control effect. This substitution eliminates complex mechanical activation mechanisms while maintaining reliable flow control through plasma generation controlled by AC voltage sources and dielectric barriers.
Solution Approach 2:
The dielectric barrier serves as an intermediary between the AC voltage source and the gas flow. It enables plasma generation without direct electrical contact, allowing selective activation of vortex generators through electrical fields while isolating the control system from the aerodynamic environment, thus simplifying the overall control architecture while maintaining reliability.
3Adaptability or versatility
If plasma actuators are used to generate plasma for flow control, then selective activation is achieved, but device complexity increases due to electrode and dielectric layer configuration
Solution Approach 1:
The patent merges multiple functional elements into integrated plasma streamwise vortex generator units. The dielectric barrier, electrodes, and AC voltage source are combined into compact modules that can be distributed along aerodynamic surfaces. This merging reduces overall system complexity by creating self-contained units that perform both structural support and plasma generation functions, rather than requiring separate systems for each function.
Solution Approach 2:
The dielectric barrier serves multiple functions simultaneously: it insulates the electrode from the gas flow, enables plasma generation through capacitive coupling, and provides a mounting surface for the AC voltage source connection. This multi-functionality reduces the number of separate components needed, thereby reducing device complexity while maintaining selective activation capability across different operational conditions.
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 PSVGs effectively maintain attached flow over aerodynamic surfaces by generating streamwise vortices only when needed, reducing parasitic drag and improving efficiency by being actively controllable based on detected flow conditions.
Implementation Method 1
The plasma actuator is configured to generate a plasma above the surface, the plasma coupling a directed momentum into the air surrounding the surface to reduce airflow separation from the surface
Implementation Method 2
When a RF voltage is applied to the electrodes sufficient to generate a discharge plasma in the gas adjacent to the substrate, the asymmetry in the electrode configuration results in force being applied to the active species in the plasma and in turn to the neutral background gas
Data Source
AI summary
A vortex generator system comprises one or more plasma streamwise vortex generators (PSVGs) or plasma wedge vortex generators (PWVGs). The PSVGs and PWVGs each comprises a first electrode and a second electrode separated by a dielectric layer. The first electrode extends in a longitudinal direction. The PSVGs and PWVGs can be installed on a surface arranged to receive airflow in a certain flow direction. The PSVGs have a rectangular first electrode is exposed and extends at least somewhat parallel to the expected flow direction, whereas the first electrode of the PWVGs is more triangular in shape. When an AC voltage is applied to the first and second electrodes, a plasma forms along edges of the first electrode. The plasma imposes a body force in a cross-flow direction, which induces a cross-flow velocity that, in combination with the mean flow, produces streamwise-oriented counter-rotating vortices.