【摘要】 通过物理模型试验,采用CQY-Z8 a型针式掺气流速仪测量了掺气射流的轴线速度,对不同条件下的掺气射流轴线速度衰减情况进行了对比研究,分析了入射水流速度、掺气浓度以及射流水股厚度对射流轴线速度衰减的影响,获得了掺气射流轴线速度衰减的变化规律。结果表明:在本试验条件下,射流轴线速度呈线性衰减;入射水流速度对射流轴线速度衰减基本没有影响,表现为不同入射水流速度时,各衰减趋势基本一致;掺气浓度越大,射流轴线速度衰减越快;射流水股厚度越小,射流轴线速度衰减越快。因此提高射流水体的掺气浓度,尽可能分散入水水体,可以加快射流轴线速度衰减,有效减弱射流对下游河床的冲刷。更多还原

【Abstract】 Based on model experiment,the velocities of jet flow along axis were measured,using the CQY-Z8a velocimeter.The velocity attenuation of the jet flow along axis under different conditions was studied.The effects of aeration concentration,jet velocity at entry and thickness of jet flow on the velocity attenuation of jet flow were analyzed.The results showed that the velocity attenuation of jet flow along axis changed in laws.Under the experimental conditions,the velocity along axis decreased linearly.The higher the air concentration,the faster the velocity decayed,and the thinner the jet flow,the faster the velocity decayed.The jet velocity itself at entry had no influence on the law of velocity attenuation,as the lines of velocity attenuation at different velocities at entry were practically parallel.Therefore,improving the air concentration of jet flow and dispersing the jet flow in the plunge pool could reduce the influence of jet flow on scour.更多还原