高压水射流的柔性冲击力是评判其能否有效破碎物料的力学判据，喷嘴的出口形状对射流的冲击力影响较大。设计了5种不同形状的喷嘴，在自主设计的水射流冲击测试平台上开展了冲击实验，并采用PVDF压电薄膜传感器和高速摄像机来记录测试数据。实验结果表明：在相同的工况下，圆形喷嘴水射流的集束性最好，冲击诱导的冲击波对流体的扩散形态影响最大，最终导致其中心冲击压力最大；依次是正方向喷嘴、三角形喷嘴与十字形喷嘴，椭圆形喷嘴的水射流形态最为发散，其中心冲击压力最小；所有喷嘴形状水射流的峰值压力均随系统泵压的增加呈现非线性增加的趋势，而峰值压力持续时间几乎保持不变。

The flexible impact force of water jet is the mechanics criterion of material breakage by water jet. The nozzle shape has a great influence on the impact pressure. Five different nozzles were designed in this paper, and the impacting tests were conducted based on the self-designed jet-impact test platform. PVDF piezoelectric film sensor and the high speed camera were used to record the experimental data. It's indicated that water jet beam from the circular nozzle presents the best strand integrity. The shock wave induced by impacting from the circular nozzle has a great influence on the diffusion form of the liquid. These features cause the highest central impact pressure of circular nozzle. The impact pressures of water jets from square, triangular and cross-shaped nozzles are much lower than that of circular nozzle. The water jet from elliptical nozzle is the most divergent and its impact pressure is the smallest consequently. The peak pressures from all shape nozzles present nonlinear relationships with the pump pressure, but the duration time of these peak pressures nearly keep constant with the pump pressure.

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国家自然科学基金青年项目（51804115，51604092）；湖南省自然科学基金青年项目（2017JJ3072，2016JJ4032）。