Repetition frequency of a DC gliding arc discharge in plasma-assisted fuel-rich combustion

¹ Laboratory of Combustion, Propulsion and Energy, Technological Institute of Aeronautics São José dos Campos, Brazil
² Laboratory of Plasmas, Films and Surfaces, Santa Catarina State University - Joinville, Brazil

^(a) armando.jpinto@yahoo.com.br

Received: 26 July 2018
Accepted: 16 September 2018

Abstract

Plasma-assisted combustion is a growing field of applied physics. In this study, a DC gliding arc plasma reactor used as part of a swirler stabilized burner was characterized to evaluate the discharge repetition frequency as a function of process parameters. The discharge was generated in fuel-rich premixed mixtures of air and natural gas. The repetition frequency was determined by applying a fast Fourier transform to the voltage waveforms. The results show that the mean voltage and mean current of the gliding arc remain almost constant as a function of the total gas flow rate. The increase in fuel concentration promotes a drop in the breakdown voltage, which leads to a rise in the discharge repetition frequency. However, for a fixed natural gas flow rate, the repetition frequency grows with the increased total mass flow rate due to a higher arc velocity.