Glow-to-arc transition in plasma-assisted combustion at 100 MPa. (16th March 2015)

• Record Type: Journal Article
• Authors: Larsson, A; Andreasson, S
• Is Part Of: Plasma sources science & technology. Volume 24:Number 2(2015:Apr.)
• Publication Date: 2015-03-16
• Subjects: plasma-assisted combustion -- glow-to-arc transition -- high-pressure discharge; 52.77.Fv -- 52.80.Tn -- 82.33.Vx; Plasma (Ionized gases) -- Periodicals; 530.44
• DOI: 10.1088/0963-0252/24/2/025023
• Languages: English
• ISSNs: 0963-0252

Abstract

Abstract: Electric energy can be added to the combustion of solid propellants in a gun in order to augment and to control parts of the internal ballistic cycle of the launch of a projectile. The pressure in the chamber and bore during launch is typically several hundred megapascal and the electric energy must be delivered to the flame at such a pressure level. To increase the understanding of the interaction between a flame and an electrical discharge at elevated pressure, experiments have been performed at 100 MPa in a combustion chamber where electric current has been conducted through the flame of a solid propellant. Pressure, voltage and current have been measured. The measured signals have been analysed and interpreted. The sequence of events has been interpreted as an initial formation of a glow-like discharge in the flame followed by a discharge mode transition to a filamentary arc discharge. The transition is shown to be dependent on the flame conductivity. For the test propellant used (Nzk5230 doped with 5% potassium nitrate), the flame conductivity is calculated to be 0.84 S m −1 and the discharge mode transition is found to occur after a dissipation of 0.2–0.4 kJ, or 11–22 kJ m −1 of electric energy, at an electric power of 0.1–0.5 MW.