Plasma and laser innovations for flight control
By Carmen Guerra-Garcia and Andrey Starikovskiy|December 2024
The Plasmadynamics and Lasers Technical Committee works to apply the physical properties and dynamic behavior of plasmas to aeronautics, astronautics and energy.
In July, researchers at Texas A&M University initiated the first experiments on laser propagation in the new 565-meter-long variable pressure Ballistic, Aero-optics and Materials Facility. BAM enables the study of laser propagation through turbulence, weather, aerosols and contaminated air, the validation of directed energy effectiveness for defense against practical threats, and the interaction of lasers with counter-propagating hypersonic projectiles. As of October, experiments were underway to develop and validate numerical simulation tools for prediction of turbulence influence on directed energy.
A number of tests were conducted that brought plasma-assisted combustion technologies one step closer to implementation in aeroengines. In February, researchers at the Laboratoire de Physique des Plasmas at Ecole Polytechnique and the Institut Prime, both in France, demonstrated that the application of nanosecond discharges ahead of a self-sustained detonation can reduce by a factor of two the detonation cell size, enhancing detonation for applications in pulsed and rotating detonation engines. In July, MIT researchers, in collaboration with engineers at Specter Aerospace of Massachusetts, demonstrated full suppression of strong limit-cycle combustion dynamics using nanosecond discharges. The tests were performed in a swirl-stabilized 6-kilowatt atmospheric pressure combustor over a wide range of methane/air mixtures, from fuel lean to stoichiometric. Also using a swirl-stabilized burner with nanosecond discharges, researchers at the EM2C laboratory of CentraleSupélec in France demonstrated a 20% extension of the operability limit (lean blowout) of pure hydrogen swirling flames and devised an actuation strategy to mitigate the nitrogen oxide emissions. Researchers from the University of Texas at Austin demonstrated fully coupled plasma/combustion by three-dimensional simulation of plasma-assisted ignition in turbulent reactive flows. In parallel, researchers at the University of Minnesota continued to develop a modeling framework that simulates in detail the discharge and combustion phases and couples them together through a detailed spatiotemporal plasma power density. The approach demonstrated good agreement with experimental measurements of gas heating, oxygen dissociation and ignition kernel evolution.
Nanosecond discharges also found applications in other areas of aerospace. In February, scientists from Princeton University in New Jersey demonstrated the possibility of investigating the initial phase of cavitation in a liquid, using a superstrong pulsed electric field to generate ponderomotive forces that in turn formed nanoscale discontinuities. In April, Princeton researchers with FAA demonstrated how a nanosecond pulsed-periodic barrier discharge can prevent ice formation on aircraft wings. Investigations conducted across a spectrum of flow temperatures, water droplet concentrations and sizes revealed a tenfold enhancement in energy efficiency compared to conventional de-icing techniques. Researchers from Xi’an Jiaotong University in China developed super-dense array plasma actuators manufactured from flexible printing circuit — in this case using AC voltage — capable of reducing drag by 22% for 20- meter-per-second flows.
In the hypersonics space, Texas A&M University researchers demonstrated how carbonaceous species could alter hypersonic plasma behavior. Their computational analysis focused on refractive index alterations in the vicinity of ablative surfaces on hypersonic vehicles, as well as propagation characteristics of radio signals traversing hypersonic plasma layers. Researchers from the University of Arizona proposed and simulated a new method for a spacecraft to enter a planet’s atmosphere, which relies on magnets and avoids the use of electrodes. Using a magnetic field of around 0.1 tesla, they predicted a force of 10 kilonewtons, which can be controlled by altering the magnetic field strength.
Contributors: Fabrizio Bisetti, Christophe O. Laux, Richard Miles, Bernard Parent, Svetlana M. Starikovskaia, Albina Tropina, Suo Yang and Wu Yun
