Saxon bowl is a timing device with a hole in the bottom. In this paper, a physical model of cylindrical Saxon bowl sinking in water is established. First, this paper determined the critical conditions for the successful sinking of the Saxon bowl, including the conditions under which water can flood into the bowl and the conditions under which the bowl is initially released. Then, this paper studied the dynamics of the system after the water pouring into the bowl and deduced the quantitative relationship between the sinking time of the bowl and the geometric characteristics of the bowl. Furthermore, experiments are designed to test the correctness of the theoretical model. Compared with the experimental sinking time of the bowl, the corresponding theoretical value is generally smaller. After taking into account the viscous resistance and differential pressure resistance in the process of bowl sinking, the loss of submerged jet and head at the orifice, and the influence of surface tension before the bowl is completely immersed, the consistency between theory and experiment is increased obviously. Finally, a wall function is introduced to analyze the sinking time of various shapes of Saxon bowls.

真空发射器是利用压强差对置于其中的弹状物体进行加速并弹射的装置.建立了简单的物理模型对真空发射器的原理和性能进行了研究,分析了影响子弹出射速度的相关参数并进行了实验验证.