Acoustic control of the structure of the gas torch

Abstract

Diffusion torches in the transverse acoustic field studied experimentally. The structure and the luminosity of the torch were recorded by a high-speed camera with shadow device and photodetectors. The dependence of the length of a laminar methane plume on the average velocity and volumetric flow rate was measured. The frequency spectra of the luminosity of the flame at different flow rates of methane are obtained. Flame flicker frequency depending on the volume flow of methane had defined according to the obtained spectra. It was found that the flame flicker frequency is not dependent on the diameter of the burner. It is shown that the flickers are caused by changes in the geometric dimensions of the flame due to the convective instability of the column of hot gas surrounding the torch. The repetition frequency of the vortices in the column of hot gas surrounding the torch coincides with the frequency of the flicker of the flame. It is shown that the limits of flame detachment from burner and flame quenching does not change at the acoustic impact on the torch, the biggest acoustic impact has on the contrary attaching detached torch. Fuel speed range, in which there is detached steady torch, increases.