• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2015, Vol. 51 ›› Issue (17): 169-176.doi: 10.3901/JME.2015.17.169

• 制造工艺与装备 • 上一篇    下一篇

风琴管喷嘴内表面粗糙度对高压射流特性的影响试验研究

李登1,2,李晓红1,2,康勇1,2,王晓川1,2,龙新平1,2,巫世晶1,2   

  1. 1.武汉大学动力与机械学院;
    2.武汉大学水射流理论与新技术湖北省重点实验室
  • 出版日期:2015-09-05 发布日期:2015-09-05
  • 基金资助:
    国家重点基础研究发展计划(973计划,2014CB239203)、教育部新世纪优秀人才支持计划[NCET-12-0424]、湖北省杰出青年基金[2012FFA020]和教育部留学回国基金[教外司留[2012]940号]资助项目

Experimental Investigation on the Influence of Internal Surface Roughness of Organ Pipe Nozzle on the Characteristics of High Pressure Jet

LI Deng1,2, LI Xiaohong1,2, KANG Yong1,2, WANG Xiaochuan1,2, LONG Xinping1,2, WU Shijing1,2   

  1. 1.School of Power and Mechanical Engineering, Wuhan University;
    2.Key Laboratory of Hubei Province for Water Jet Theory & New Technology, Wuhan University
  • Online:2015-09-05 Published:2015-09-05

摘要: 风琴管自振空化喷嘴因兼具空化射流与脉冲射流的优点而被广泛使用。为探究大雷诺数下风琴管喷嘴内表面粗糙度对高压射流特性的影响,从而提高喷嘴作业效率。在理论分析紊流特性与表面粗糙度关系的基础上,通过试验探究了风琴管喷嘴内表面粗糙度对射流轴心压力脉动与扩散角的影响规律。试验结果表明,入口压力越大,粗糙度对射流的扩散角、轴心压力脉动峰值、压力脉动幅度的影响程度越大;对某一入口压力,存在一对应起始粗糙度值使得扩散角快速增大,轴心压力脉动峰值与压力脉动幅值急剧衰减;且入口压力一定时,存在一临界粗糙度值,粗糙度小于此值时,轴心压力脉动峰值与压力脉动幅值随靶距增大而先增大后减小;粗糙度大于此值时,轴心压力脉动峰值与压力脉动幅值随靶距增大而减小。根据试验数据,运用能量守恒定理,建立了射流轴心压力脉动峰值随表面粗糙度、入口压力、靶距变化关系的初步数学模型。

关键词: 粗糙度, 风琴管喷嘴, 扩散角, 压力脉动

Abstract: The organ-pipe nozzle is widely used because of its generation of self-resonating cavitating jets which combines the advantages of cavitating jets and pulsed jets. In order to improve the working efficiency of organ-pipe nozzle by studying the influence of internal surface roughness on the characteristics of high pressure jet under high Reynolds numbers, the relations between turbulent boundary layer and surface roughness are theoretically analyzed, and the laws of the axial pressure fluctuation and the diffusion angle of the jet are investigated by experiment. The results show that, the peak pressure, the rage of pressure fluctuation and the diffusion angle are influenced more greatly by the surface roughness when the inlet pressure is greater. There exists a minimum roughness number, above which the diffusion angle starts to increase while the peak pressure and the rage of pressure fluctuation starts to decrease greatly. For a certain inlet pressure, there exists a critical roughness number, below which the axial pressure fluctuation increases at first and then decreases with the increase of stand-off distance, while above which the axis pressure fluctuation only decreases when the stand-off distance increases. Based on the experimental data, a preliminary mathematical model of the axial peak pressure relating to inlet pressure, internal surface roughness and stand-off distance was established by utilizing the principle of conservation of energy.

Key words: diffusion angle, organ-pipe nozzle, pressure fluctuation, surface roughness

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