Influence of electric fields on premixed laminar flames: Visualization of perturbations and potential for suppression of thermoacoustic oscillations

Overview of Electric Field Applications in Energy and Process Engineering

“…Electric fields could be transmitted through ceramic walls of the combustion chamber for possible realization of flame control. In this case, Many fundamental experiments using lab-scale burners have been carried out for studying electric field enhanced combustion using premixed (see, e.g., [22][23][24][25][26][27][28][29][30]) and non-premixed flames [31,32]. Attempts for a technical application at higher thermal load were conducted by Weinberg et al for a meso-scale burner [33], by Sakhrieh et al for a Bunsen flame array [34] and Altendorfner et al [35] for a swirl flame that is usually applied in gas-turbine burners.…”

“…Furthermore, thermo-acoustic oscillations [26,28,38] can be suppressed or generated [38][39][40] by using electric fields and, currently, this topic is of high interest. Thermo-acoustic oscillations may occur in the combustor at a certain load and could potentially damage the burner and combustion chamber [41].…”

“…However, weak DC electric fields could also be used to dampen these flame oscillations [26]. For suppression of these instabilities, the flame response time on the electric field must be known in order to determine the capability of the electric field to vary the flames "convection time" and oscillation frequency.…”

“…Furthermore, particle image velocimetry (PIV) was used for measurement of the flow field variation in the flame that was subjected to the electric field. It was described that the flame responds to the e-field within 2-4 ms [25,26], while the shape of the flame was not significantly changed. After activation of the electric field, a disturbance was initialized at the bottom of the flame.…”

“…In Refs. [25,26], it was shown that the flame can adopt the frequency of a transient weak electric field up to 200 Hz. For 200 Hz, the period between activation and deactivation of the e-field is much shorter than the flame response time (which is about 2-4 ms, as mentioned above).…”