The flame front of a premixed ethylene–air turbulent flame in a high-speed flowfield was imaged using hydroxyl radical (OH) planar laser-induced fluorescence (PLIF). An electrically heated continuous flow facility produced inflow conditions with a total temperature of 1200 K, corresponding to a flight Mach number of about five. A statistically stationary turbulent flame stabilized over a scaled-down cavity was used to generate experimental data for future comparisons with direct numerical simulations. A laser sheet with a wavelength of 283.55 nm was used to excite the $Q_1$(8) transition of OH. The sheet waist had a full width at half-maximum of $95\mu \mathrm{m}$. Two-dimensional OH-PLIF images were collected at high in-plane spatial resolution (approximately $40\times 40\mu \mathrm{m}$) with a field of view of $5.6\times 5.6\mathrm{mm}$. The images spanned a region of $45\times 15\mathrm{mm}$ along the spanwise centerplane. The local OH gradient was used to isolate the flame front in all images through an automated process. Each image was processed to obtain the appropriate statistics, time-averaged flame surface density, and flame front curvature values. The distribution of local flame front curvature values was approximately constant across the domain.

使用羟基自由基（OH）平面激光诱导的荧光（PLIF）对高速流场中预混合的乙烯-空气湍流火焰的火焰前锋进行成像。电加热的连续流设施产生的流入条件的总温度为1200 K，对应于约5的飞行马赫数。在缩小的腔体上稳定的统计静止湍流火焰用于生成实验数据，以便将来与直接数值模拟进行比较。使用波长为283.55 nm的激光片来激发${问}_{\mathrm{1个}}$（8）OH的过渡。床单腰部的最大宽度为最大宽度的一半$95\mu \mathrm{米}$。二维OH-PLIF图像以较高的面内空间分辨率（大约$40\times 40\mu \mathrm{米}$）的视野 $5.6\times 5.6\mathrm{毫米}$。图像跨越了一个区域$45\times 15\mathrm{毫米}$沿翼展方向中心平面。通过自动过程，使用局部OH梯度隔离所有图像中的火焰前锋。对每个图像进行处理以获得适当的统计信息，时间平均的火焰表面密度和火焰前曲率值。局部火焰前曲率值的分布在整个区域内大致恒定。