This study investigates the flame-flow interaction during a fully-premixed swirl flame flashback from flame-frame-of-reference. To capture the flame front movement during upstream propagation, high-speed chemiluminescence imaging and simultaneous three-component PIV measurements are taken at 4 kHz. The upstream propagation of the flame occurs along a helical path around the center-body. For low-turbulence and high-swirl conditions (Re_h = 4000, Swirl number ∼ 0.9), the lab-frame speed of the flame structure remains nearly constant during the period of investigation. Simultaneously, the leading side of the flame tongue retains its topology during propagation. The steady-state propagation behavior of the flame structure and stationarity of the flame topology allows us to make a frozen-flame-surface assumption. Applying space-time equivalence, the three-dimensional flame surface and flow field are reconstructed by shifting and stacking the time-series of the planar flame front profiles and the three-component planar velocity data. Further, the steady flow in the flame frame-of-reference provides a powerful means of investigating the flame-flow interaction. Quasi-pathlines are constructed in the unburnt and burnt regions of the flow field. The motion of the approach flow along a quasi-pathline is analyzed to understand the role of centrifugal and Coriolis forces. It is shown that the tug-of-war situation between Coriolis and centrifugal forces gets disrupted by the dilatation-driven blockage effect from the flame surface. It leads to a radial deflection of the approach flow, which results in reduction in the flame-normal approach flow speed, thereby assisting in the flame propagation. In the burnt gas, the Coriolis Effect bends the pathlines towards the center-body. We show - for the first time - that the azimuthal motion of the flame assists in the upstream propagation of the flame structure. Error assessment shows that the approximations made to construct the flame-surface and the flow-field retains the physics of flame-flow interactions.

这项研究从参考火焰框架研究了完全预混的旋流火焰回火过程中的火焰流相互作用。为了捕获上游传播过程中火焰的前移，在4 kHz处进行了高速化学发光成像和同时的三分量PIV测量。火焰的上游传播沿着围绕中心体的螺旋路径发生。对于低湍流和高涡流条件（Re _h = 4000，旋涡数〜0.9），在研究期间，火焰结构的实验室框架速度几乎保持恒定。同时，火焰舌的前侧在传播过程中保持其拓扑结构。火焰结构的稳态传播行为和火焰拓扑的平稳性使我们能够做出冻结的火焰表面假设。应用时空等效，通过平移和堆叠平面火焰前轮廓的时间序列和三分量平面速度数据，重建三维火焰表面和流场。此外，火焰参照系中的稳定流动提供了研究火焰-流动相互作用的有力手段。在流场的未燃烧区域和燃烧区域中构造了准路径。分析了进场流沿准路径的运动，以了解离心力和科里奥利力的作用。结果表明，科里奥利力和离心力之间的拔河态势被来自火焰表面的膨胀驱动的阻塞效应所破坏。这会导致进场气流发生径向偏转，从而导致火焰法向进场流速降低，从而有助于火焰传播。在燃烧的气体中，科里奥利效应使路径线向中心体弯曲。我们首次展示了火焰的方位角运动有助于火焰结构的上游传播。误差评估表明，构造火焰表面和流场的近似值保留了火焰-流相互作用的物理性质。