Simultaneous measurements of OH, mixture fraction and velocity fields to investigate flame stabilization enhancement by electric field

Abstract

Simultaneous stereoscopic PIV, OH and acetone planar laser-induced fluorescence measurements are performed to analyze the processes involved in the enhancement of flame stabilization by electric field. Instantaneous velocity and mixture fraction fields are measured simultaneously at the base of a lifted flame to analyze whether the flow properties in front of the flame when electric field is applied are compatible with a mechanism involving ionic wind. The measurements conditioned on the instantaneous flame bases with and without the electric field are compared. The velocity in front of the flame decreases with electric field what is in agreement with the assumption involving ionic wind. To analyze the mixture in front of the flame, a joined analysis of velocity and mixture fraction is required to show the mixture stays near stoichiometry when the electric field is applied. The need of a joined analysis illustrates the interest of performing the three laser diagnostics simultaneously.

Overview of Electric Field Applications in Energy and Process Engineering

“…Cessou et al [155] measured fuel concentration using acetone-PLIF in the cold flow of a non-premixed propane flame that is stabilized by an electric field. Simultaneously, the velocity Energies 2018, 11, 1361 24 of 33 field was studied using PIV and the flame was visualized using OH-PLIF.…”

The Reattachment Process of a Lifted Jet Diffusion Flame by Repetitive DC Pulse Discharges

“…To increase the current flowing through the flame, a two-electrode configuration was used to augment the coupled effect of DC electric field on the flameedge. The resultant modifications on the flame/flow behaviors in the premixed jet flame [5] and the lifted flame base [6] were delineated based on the ion-driven-wind (ionic wind) model. On the other hand, at the higher E/N field, the electrons can directly induce the production of ions, high-level excited species, and chemically active species during the electrical pulse to form a self-sustained plasma discharge [7].…”

“…Although the electric/plasma assisted combustion enhancement phenomena [1][2][3][4][5][6][7], especially on the reattachment enhancement of a lifted flame [8][9][10][11][12]15], are interesting and may be of paramount importance to practical application on flame stabilization, the detailed plasma assisted reattachment process and mechanism, and the role of induced corona discharge and the role of corona-induced ozone on the enhancement of the reattachment process, are still unclear and undocumented. Accordingly, the present study is focused on the enhanced reattachment behaviors and forced propagation process of a lifted nonpremixed propane jet flame by repetitive pulsed DC discharges.…”

A spectral deferred correction strategy for low Mach number reacting flows subject to electric fields

“…Three major effects have been advanced in the literature [1]: 1) the collision of charged particles with neutral ones induces a bulk convective transport in the gas called the ionic wind effect; 2) the transport of highly reactive charged particles from the reactive layer of the flame to the low temperature zone enhances the fuel oxidation rate; and 3) for strong electric fields ohmic heating increases the flame temperature, resulting in a higher flame speed. These processes were found to have an effect on flame speed [7,8,9,10,11], flame stabilization [12] and NO x and soot formation [13,14,15]. The extent to which each process is important depends on the applied potential difference, the polarity, the distance between the electrodes and the flame, and the operating conditions, making it difficult to compare results from different experiments and to provide clear design guidelines for engineers.…”