We present details of an image analysis algorithm designed specifically to determine the velocity of material in the melt plume during high-pressure, close-coupled gas atomization. Following high-speed filming (16,000 fps) pairs of images are used to identify and track dominant features within the plume. Due to the complexity of the atomization plume, relatively few features are tracked between any given pair of images, but by averaging over the many thousands of frames obtained during high-speed filming a spatially resolved map of the average velocity of material in the plume can be built up. Velocities in the plume are typically very low compared to that of the supersonic gas, being around 30 m s−1 on the margins of the plume where the melt interacts strongly with the gas and dropping to < 10 m s−1 in the center of the melt plume. Consequently, the efficiency of the atomizer in transferring kinetic energy from the gas to the melt is correspondingly very low, with this being estimated as being no more than 0.1 pct.

中文翻译：

---

液态金属高压气体雾化过程中熔体羽流的空间分辨速度映射

我们提供了一种图像分析算法的详细信息，该算法专门用于确定高压、紧密耦合气体雾化过程中熔体羽流中材料的速度。在高速拍摄 (16,000 fps) 之后，成对的图像用于识别和跟踪羽流内的主要特征。由于雾化羽流的复杂性，在任何给定的图像对之间跟踪的特征相对较少，但通过对高速拍摄期间获得的数千帧进行平均，羽流中物质平均速度的空间分辨图可以被建立起来。与超音速气体相比，羽流中的速度通常非常低，在熔体与气体强烈相互作用的羽流边缘约为 30 ms-1，在熔体中心降至 < 10 ms-1羽。