Experimental Study on the Effect of Freestream Turbulence on the Mass Burning Rate of Wind-Driven Flames with an Unheated Segment
摘要
This study investigates the impact of an unheated starting segment on the burning characteristics of a turbulent wind-driven flame sustained over a fuel wick soaked with n-heptane. Freestream flow parameters were varied in terms of velocity (U = 1–2 m/s) and turbulence intensity (TI = 1.8–16%). Two unheated segment lengths were chosen as L0 = 5 cm and 10 cm. Results show that the flame structure varies significantly by varying the length of the unheated segment. Flame streak interactions were more pronounced for the L0 = 5 cm case, with increased merging and lateral motion. At higher turbulence levels, the flame streaks showed sinuous, curvy, and wavy motions. The mean mass burning rate increases with both freestream velocity and turbulence intensity. However, a longer unheated segment resulted in a reduction in the mean mass burning rate. These findings provide valuable insights into the burning characteristics of wind-driven flames and establish a fundamental framework for understanding flame dynamics in real-world fire scenarios.