摘要
为解释流动对射流空化和空蚀的影响,以ASTM G134射流空蚀实验台为对象,应用计算流体动力学方法揭示空蚀腔内的空化区形态,进而开展空蚀试验,获得试样表面的空蚀形貌,与模拟结果进行对比分析。结果表明:射流在空蚀腔内保持平稳发展的形态;射流核心段存在高速区,其外围为环形低压区,该环形区是产生射流空化的关键;射流与试样表面接触后,试样表面的空蚀区与环形空化区相对应。试验结果表明,在空蚀试验初期,试样表面的空蚀区呈环形,与模拟结果一致;随着空蚀的发展,环形空蚀区扩大,空蚀由环形区向试样中心区扩散;空蚀时间的继续延长导致试样中心区亦出现严重的材料剥落,此时试样的累积质量损失仍在增长,但累积质量损失率保持稳定。
To explain effects of jet flow on jet cavitation and cavitation erosion,an investigation was carried out based on the ASTM G134 standard waterjet cavitation erosion test rig.Computational fluid dynamics technique was used to reveal cavitation patterns in the test chamber.Furthermore,experiments were performed to obtain morphologies of the eroded surfaces,which were also used for a joint analysis with simulation results.The results indicate that the waterjet in the test chamber manifests a stable development pattern.High velocity arises in the core region of the jet stream,while an annular lowpressure zone enclosing the core region is found.Such an annular low-pressure zone is vital for the generation of cavitation.As the jet arrives at the specimen,an annual area on the specimen surface that corresponds to the annular cavitation zone in the jet stream is supposed to be the eroded area.The cavitation erosion experiment results indicate that a ring cavitation erosion zone arises at the initial stage of cavitation erosion.As cavitation erosion progresses,the ring erosion zone is expanded and cavitation erosion is extended to the central part of the specimen surface.Further elongation of cavitation erosion gives rise to severe material removal that occurs in the central region as well.Meanwhile,the cumulative mass loss rises consistently;however,the cumulative mass loss rate remains nearly invariant.
作者
周明明
康灿
刘海霞
陈金豪
ZHOU Mingming;KANG Can;LIU Haixia;CHEN Jinhao(School of Energy and Power Engineering,Jiangsu University,Zhenjiang 212013,China;School of Material Science and Engineering,Jiangsu University,Zhenjiang 212013,China)
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2018年第6期133-142,共10页
China Surface Engineering
基金
国家自然科学基金(51775251
51376081)~~
关键词
空化射流
ASTM
G134标准
空蚀
流场
数值模拟
cavitating waterjet
ASTM G134 standard
cavitation erosion
flow field
numerical simulation
