This paper reports on the effect of DC electric fields on the dynamics of a premixed methane-air laminar flame, in a buoyant environment. DC electric fields can be capable of affecting both the buoyancy-driven flickering oscillation of the flame and the response of the flame to acoustic modulation of the flow. We conduct fast visualization of the emission of excited methylidyne radicals (CH^*), representing the heat release rate of the flame. Such visualizations are also synchronized with electric current and voltage measurements. We notice that the suppression of buoyancy-driven flickering oscillations can be obtained by applying sub-critical negative DC voltages. Moreover, the current measured in the inter-electrodes area is analyzed for positive and negative DC applied voltages and we find that this quantity cannot be used as a tracer of heat release rate in a configuration where the flame location in the inter-electrodes gap varies with sub-critical electric fields. In addition, the effect of DC electric fields on the flame transfer function for acoustic modulation of the flow is reported and discussed.

本文报告了在浮力环境中直流电场对预混合甲烷-空气层流火焰动力学的影响。DC电场能够影响火焰的浮力驱动的闪烁振荡和火焰对流动的声学调制的响应。我们对激发的亚甲基自由基（CH ^*)，代表火焰的放热率。这种可视化也与电流和电压测量同步。我们注意到，可以通过施加亚临界负直流电压来抑制浮力驱动的闪烁振荡。此外，分析了在电极间区域测量的电流的正负直流施加电压，我们发现在电极间间隙中的火焰位置发生变化的配置中，该量不能用作放热率的示踪剂与亚临界电场。此外，报告和讨论了直流电场对火焰传递函数的影响，用于对流动进行声学调制。