Complex gravity-acoustic impact on M-flame structure

Abstract

Ensuring fire safety is one of the most important problems in the creation of habitable spacecraft. It is necessary to thoroughly study the issues of the reliability of the functioning of space systems, including those using chemical fuel. The paper studies experimentally the dynamics of an M-shaped premixed methane-air flame under normal and reversed gravity at various external acoustic excitation. The stable M-shaped flame is studied experimentally by means of high-speed video recording of flame chemoluminescence and PIV-methods. The paper shows that at low frequencies of acoustic excitation, the flame front remains practically undisturbed. At a 160 Hz frequency, the oscillatory motion is energetically more saturated than the main gas flow. With a further frequency increase, the main flow again becomes dominant in terms of energy, and the effect on the flame structure decreases.