Study on dynamics of droplet impacting on the zirconium alloy tube surface and the modeling of maximum spreading factor

To reduce scratches caused during the assembly of fuel assemblies, an ice film can be prepared on the zirconium alloy tube surface before assembly to reduce or even prevent scratches. The quality of the ice film is directly affected by the maximum spreading factor. For this purpose, it is crucial to describe the relationship between droplet parameters and the maximum factor. In this study, first, the high-speed camera technology was used to investigate the droplet impact dynamic behavior on zirconium alloy tubes and the effect of droplet parameters on the spreading process. Then, the theoretical model of the maximum spreading factor is established based on energy conservation and combined with rotational momentum and cylindrical anisotropy, and the polynomial regression and intelligent algorithms were used for comparison. The results show that the deviation is within ±10%. Still, the evaluation indicators of the model established in this study are superior to the other models. The results show that the theoretical model can accurately reflect the non-linear relationship between the droplet parameters and the maximum spreading factor. This study provides data support and a theoretical basis for subsequent control of the liquid film shape and the preparation of high-quality ice films.