DC-Augmented Dielectric Barrier Discharge (DCA-DBD)

TL;DR

This study investigates how external DC fields influence dielectric barrier discharges, revealing complex plasma interactions and identifying a new mechanism that significantly enhances horizontal thrust in electromechanical systems.

Contribution

It introduces a novel understanding of DBD interactions under DC augmentation, including a new residual charge mechanism that boosts horizontal thrust.

Findings

Negative DCA modestly improves momentum transfer.

Positive DCA increases wall-parallel force.

Residual charge interaction mechanism causes over 2-fold thrust increase.

Abstract

Time-dependent multiphysics interactions that drive the energy transfer in electromechanical systems are poorly understood. We probe dielectric barrier discharge (DBD) with an external DC-augmented (DCA) field to reveal new mechanistic insights. The biased HV DC electrode influences the interaction between the charged ions and the E-field, surface and space charge, and neutral molecules. Direct force measurement, velocity profiles, and time-resolved electrical and optical measurements of discharge characteristics provide evidence of complex plasma/flow interactions. Negative DCA leads to modest improvements in momentum transfer due to the field-augmented ion acceleration before the system transitions to sliding discharge and a counter jet at the DCA electrode, canceling the gains from positive ion acceleration. Positive DCA monotonically increases the wall-parallel force. A new oscillating residual charge interaction mechanism is identified to explain a greater than 2-fold increase in horizontal thrust, in which the acceleration of positive ions is augmented by the attraction from the residual (negative) charge.