异重流交界面波动失稳条件  

Interfacial instability in density currents

作　　者：范家骅[1] 

机构地区：[1]中国水利水电科学研究院,北京100048

出　　处：《水利学报》2010年第7期849-855,共7页Journal of Hydraulic Engineering

摘　　要：本文讨论盐水或浑水(浮泥)交界面在水流作用下,发生不同振幅和频率的交界面波动,乃至界面波失去稳定时的水力和介质密度性质的条件。通过试验观察浮泥层在水力作用下交界面波动以及界面波失去稳定时的物理现象,测定了界面波破碎的临界流速。该结果与盐水的临界流速试验结果,可用于估计两种异重流交界面的临界流速。进一步的研究发现用Keulegan的界面波失去稳定的条件,即Uc和(νgΔρ)/ρ1/3的关系,也可估计其临界流速。由于盐水和浑水的运动黏滞系数ν与密度差的关系有相同的规律,故可用较简单的密度差和临界流速的关系线,估计界面波失去稳定时的临界流速。Critical velocity of wave breaking at the interface between clay mud suspension and interface of clear water and saline water was discussed. This physical phenomenon was observed in experiments. The critical velocities for wave breaking were recorded. Experimental curves of critical velocity Uc, versus （△ρ）1/2 and Uc versus （vg△ρ/ρ）1/3 were plotted for the saline water and mud suspension. Because the relationship between the measured v and （△ρ） is the same for both the saline and turbid water layers, the curve of U versus （△ρ）1/2 can be used as a conventional method to estimate the critical velocity.

关 键 词：异重流 异重流交界面 浮泥起动流速 盐水楔界面混合 

分 类 号：TV143[水利工程—水力学及河流动力学]