|
| Electromagnetic Boundary Layer Flow Control |
| Check here for EMFC Videos |
The purpose of this research project is to develop a physical understanding of the interaction of electrically charged nanoparticles with electromagnetic fields in boundary layers. After gaining an understanding, the concept will then be applied to generate control forces for aerodynamic applications. Magnetohydrodynamic theory shows that crossing a current field with a magnetic field can be used to generate a Lorentz body force to accelerate or retard a fluid flow. These principles have been used in MHD flow accelerators and power generators for hypersonic vehicles, and can be used for other applications like turbulence suppression. Present high-speed vehicle control requires the use of bulky control surfaces or reaction jets which cause undesirable aerodynamic interference with other vehicle components. |
|
Our electromagnetic flow control (EMFC) approach involves seeding an air flow with electromagnetically conducting nanoparticles ('cold plasma') before passing it though an electromagnetic field which will generate the Lorentz body force on the flow. Theoretical studies show that EMFC can provide control forces and moments comparable to to those provided by a traditional flap without the bulk and increased drag. Previous research in this field has shown that EMFC devices use an impractically high amount of power in order to generate the electromagnetic field. However, applying artificial seeding to a small control volume in a boundary layer may be feasible. Our low speed experiments will run at speeds up to 30 m/s and the high speed experiments will run at Mach 2.5. |
| |
Pictured below is a 3D theoretical study of the Lorentz force that will accelerate a conducting cold plasma. The Lorentz force is created with several electrode pairs, each pair placed around a rare earth magnet. Near the plate, the Lorentz force becomes much stronger in the boundary layer region. The Lorentz force peaks at the electrodes, but a nearly uniform force can be created by manipulating the geometry of the electrode and magnet configuration. Also pictured below is a diagram of the electric, magnetic, current, and velocity field vectors crossed to produce the Lorentz accelerating force for a two magnet, three electrode combination. Reversing the magnetic polarity will change the force to one that retards the flow. |
 |
 |
| |
Optical flow measurements will be critical to understanding the nature of the interaction of the electrically charged nanoparticles with the electromagnetic fields. We have instrumentation available to measure flow characteristics such as particle velocity distribution, plasma conductivity, and seed distribution. |
|
