3D Flame surface density measurements via orthogonal cross-planar mie scattering in a low-turbulence bunsen flame
3D Flame surface density measurements via orthogonal cross-planar mie scattering in a low-turbulence bunsen flame
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DOI：
10.1016/j.proci.2022.07.076
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发表时间：
2022-08
影响因子：
3.4
通讯作者：
Yutao Zheng;L. Weller;S. Hochgreb
中科院分区：
文献类型：
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作者：
Yutao Zheng;L. Weller;S. Hochgreb
准瞬时米氏散射测量进行确定火焰表面的位置，使用两个正交的平面，以获得3D取向和测量的3D火焰表面密度（FSD）的稳定的先导本生燃烧器的湍流水平的1至2.5倍的层流火焰速度。将双脉冲527 nm高频激光（高频粒子图像测速双头装置的一部分）通过偏振器分成两个分离的激光束，以在垂直平面和水平面上产生3 kHz的激光片。横跨本生稳定火焰的中心线的垂直平面保持恒定，而水平面的高度从火焰的底部调整为不同的高度。火焰边缘定义为液滴痕迹消失的位置，并根据火焰边缘数密度的局部变化计算。利用火焰法向矢量在两个测量平面上的投影计算每个平面上的指向角，并根据两个平面相交线处的测量角度估算三维火焰传播速度。对于有和没有平均角度校正的病例，比较了2D与3D FSD幅度。结果表明，二维FSD近似值比三维测量值低20-30%，如果不校正，校正后高达28%。
Quasi-instantaneous Mie scattering measurements were conducted to determine the flame surface location using two orthogonal planes to obtain the 3D orientation and measurement of 3D flame surface density (FSD) on a stabilised piloted Bunsen burner with turbulence levels of 1 to 2.5 times the laminar flame speed. A double-pulsed 527 nm high-frequency laser (part of a high-frequency particle image velocimetry dual-head setup) was split into two separated laser beams through a polarizer to generate laser sheets at 3 kHz on a vertical plane and a horizontal plane. The vertical plane across the centerline of the Bunsen-stabilized flame was kept constant, whilst the height of the horizontal plane was adjusted from the base of the flame for different heights. The flame edge was defined as the location where droplet tracers disappear, and calculated based on the local change in the number density of the flame edge. Projections of the flame normal vector onto two measurement planes were used to calculate directing angles on each plane, and the 3D FSD was estimated based on the measured angles at the intersecting lines of two planes. A comparison of the 2D to 3D FSD magnitudes was made, for cases with and without mean angle corrections. The results show that the 2D FSD approximations are lower than the 3D measurements by a factor of 20–30% if uncorrected, and up to 28% after corrections.