General models of buoyant sidewall flame morphology affected by crossflows on the inclined surface based on the mirror approach

Abstract

This paper investigates the evolution of sidewall flame morphology on inclined surfaces subjected to crossflows. Experiments were conducted with 125 different experimental conditions using propane as the fuel. The study focuses on the sidewall flame tilt angle, flame length, and flame attachment length. The sidewall flame tilt angle is smaller than that of the non-sidewall flame since the boundary layer on the sidewall surface exerts horizontal friction on the flame. The sidewalls constrain the air entrainment of the flame causing the sidewall flame length to be greater than the non-sidewall flame length. The relationship between the sidewall flame attachment length and the non-sidewall flame attachment length is related to the extent of flame tilting and the friction in the vertical direction to which the flame is subjected. The mirror approach was utilized to quantify the impact of sidewalls on flames. General correlations were proposed for the sidewall flame tilt angle, flame length, and flame attachment length, by analyzing the forces acting on the flame. These prediction models were found to be in good agreement when compared to non-sidewall flame data from previous studies.