A review: Flame front propagation in a horizontal tube of variable length.

The phenomenon of flame propagation within cylindrical conduits, including both surfaces with minimal irregularities and those exhibiting roughness, as well as those harboring obstacles, constitutes a prominent subject of investigation within contemporary scientific inquiry. The transportation of gas fuels with varying reactivity levels in different combinations is of great significance due to their widespread utilization. The present review paper elucidates the intricate mechanism underlying the formation of tulip flames within the confines of horizontal combustion chambers. The tulip flame is a manifestation solely governed by hydrodynamics, arising from the interplay between the retrograde motion of deflected combusted gases expanding from the flanking regions of the flame and the progressive motion of unburned gases propelled forward within the finger-like structure of the flame. This intricate interplay significantly influences both the configuration and efficacy of the combustion system. Extensive research endeavors have been undertaken to explore the intricate phenomenon of flame propagation and its associated velocity. Nevertheless, the findings of these investigations have been dispersed among diverse scholarly outlets, including esteemed journals and esteemed conference proceedings. The primary aim of this manuscript is to amalgamate an extensive corpus of scientific investigations and present it in a manner conducive to critical examination. [ABSTRACT FROM AUTHOR]