空气射流动力学特征与冲沙作用试验研究

Experimental study on dynamic characteristics and sand flushing of aerated jet

针对空气射流冲沙方法目前相关理论研究还不够深入的现状,利用水下排气冲击细颗粒床沙,对空气射流的动力学特征与冲沙作用进行水槽试验。在空气射流清水试验中,总结归纳了羽流发展的4个阶段,通过正交试验信噪比分析发现气压是羽流下切长度的主要影响因素,局部紊动强度随空气射流压强的增大而增大,且沿横向迅速衰减。在气动冲沙浑水试验中,总结归纳了冲沙坑的3个发展阶段,通过正交试验信噪比分析确定了影响冲沙效果的显著因素,并利用方差分析建立冲沙效果回归方程,预测值与实测值对比结果表明该方程预测效果较好。

Aiming at the status that the relevant theoretical research of aerated jet flushing to solve the problem of local sediment deposition is not deep enough, the dynamic characteristics and sand flushing effect of aerated jet were studied by flume experiment. In the gas water clear water test, four stages of plume development are proposed. Through the signal-to-noise ratio analysis of orthogonal test, it is found that the air pressure is the main factor affecting the undercut length of the plume, and the local turbulence intensity increases with the increase of air jet pressure, and decays rapidly along the transverse direction. In the pneumatic sand flushing muddy water test, three development stages of sand flushing pit are proposed. Through the signal-to-noise ratio analysis of orthogonal test, the main effect affecting the sand flushing effect is determined. The regression equation of sand flushing effect is established by variance analysis, and the comparison between predicted and measured values shows good prediction results of the regression equation.