This study focuses on the scale effect of transverse gas fuel injected into a Ma=2.95 supersonic flow. NPLS (Nanoparticle-based Planar Laser Scattering) and oil flow techniques were employed to obtain flow structures and jet penetration, while the RANS (Reynolds-averaged Navier-Stokes) model was utilized to investigate fuel mixing characteristics. In order to get the scale effect law, the diameters of jet orifice were chosen as $D=2$ mm and $D=4$ mm, and the jet-to-crossflow dynamic pressure flux ratio (J) were set as 2.3, 5.5, and 7.7. The jet penetration boundary could be extracted from NPLS images. By analyzing plenty of NPLS images, a corrected fitting formula was given, which could reflect the scale effect law of jet penetration. The oil flow experiments compared the shapes and the size of the V-shape recirculation zone of different scales. Results showed that the size of the recirculation zone amplifies proportionally with the diameter of the orifice growth. The RANS numerical simulations were conducted to study the mixing characteristics, and the detailed fuel mass fraction concentration and mixing efficiency analysis were given. It is concluded that the turbulent boundary layer plays an important role in the scale effect of the jet penetration and mixing characteristics, especially for the low jet-to-crossflow dynamic pressure flux ratio (J).

本研究侧重于注入 Ma=2.95 超音速流的横向气体燃料的尺度效应。NPLS（基于纳米粒子的平面激光散射）和油流技术被用来获得流动结构和射流穿透，而RANS（雷诺平均纳维-斯托克斯）模型被用来研究燃料混合特性。为得到尺度效应规律，选择射流孔口直径为$D=2$ 毫米和 $D=4$mm，射流与横流的动态压力通量比（J) 分别设置为 2.3、5.5 和 7.7。射流穿透边界可以从 NPLS 图像中提取。通过对大量NPLS图像的分析，给出了一个能反映射流穿透尺度效应规律的修正拟合公式。油流实验比较了不同尺度的V形回流区的形状和大小。结果表明，再循环区的大小与孔口生长的直径成正比。通过RANS数值模拟研究了混合特性，并给出了详细的燃料质量分数浓度和混合效率分析。得出的结论是湍流边界层在射流穿透和混合特性的尺度效应中起着重要作用，特别是对于低射流与横流动压通量比（J )。