围压条件下空化磨料射流的冲蚀特性与机制分析

Erosion Characteristics and Mechanisms of Cavitating Abrasive Water Jet under Confining Pressure

磨料射流在水利水电、石油工程和海洋资源开发等领域有着广泛的应用,研究射流的冲蚀特性和破坏物料机制对提高水射流利用效率具有重要意义。利用自行研制的实验装置,研究了围压条件下自振空化、文丘里和锥形3种喷嘴形成的磨料射流冲蚀特性,分析了空化磨料射流冲蚀物料的机制。结果表明:自振空化喷嘴和文丘里喷嘴的冲蚀效果优于锥形喷嘴,空化作用有助于提高磨料射流的冲蚀效果;磨料射流的冲蚀效率随围压的增大而降低,主要原因是围压对纯水射流和空化磨料射流的压力脉动和冲击力具有抑制作用。分析认为,空化磨料射流冲蚀破碎物料的机制主要包括冲蚀、气蚀和共混磨蚀3种作用。

Abrasive water jet is widely used in water resources and architectural engineering,oil and gas engineering and marine resources development. It is significant to study the erosion characteristics of the jet and material destruction mechanisms to improve the efficiency of water jet. Using the selfdeveloped device, the experiments were performed on abrasive water jet erosion characteristics formed by three types of nozzles including self-oscillating cavitation nozzle, Venturi nozzle, and cone-shaped nozzle under confining pressure. Destruction mechanisms of metal material were also analyzed. The results show that the erosion efficiencies of the self-oscillating cavitation nozzle and Venturi nozzle are higher than that of the cone-shaped nozzle ~ cavitation erosion can help improve the efficiency of abrasive water jet. Abrasive water jet erosion efficiency decreases with the confining pressure increasing, mainly due to the confining pressure inhibiting pressure pulse, cavitation effect, and impinging pressure. The mechanism of materials by cavitating abrasive water jet includes three roles of impact erosion, cavitation and their synergism.