分层水环境曝气诱导形成内波的过程与特性

采用分层水库模型，在平均温度梯度为0.37℃/cm条件下，开展了系统的曝气诱导内波的中试研究.分析了曝气诱导形成内波的过程，探究了曝气诱导形成内波的类型，重点揭示了曝气扰动源形式和跃温层厚度对内波形成过程和特性的影响.实验结果表明：扬水曝气产生的气水两相流是一种非定常的周期性扰动源，气水两相流的尾迹带动整个模型水体上下振动，这种振动在分层水体跃温层处诱导形成内波.从激发源角度上说，它是一种尾迹效应波.气弹释放周期在44.06～58.69s之间时，内波波高达到最大，当气弹释放周期达到180s时不能形成连续的内波；曝气器出流口增大，内波波高、周期呈增大趋势.分层水体的跃温层厚度也影响内波的形成，相同温度梯度条件下，随着跃温层厚度的增加，内波的波高、周期随之增大.

Process and characteristics of aeration-induced internal waves in stratified water environments

Systematic pilot experiments were performed under an average temperature gradient of 0.37℃/cm over the thermocline in a stratified reservoir model. The process of inducing internal waves by aeration was analyzed, the types of aeration-induced internal waves were explored, and the effects of disturbing source from aeration and the thickness of the thermocline on the generation and characteristics of internal waves were mainly investigated. The air-water two-phase flow generated from the water-lifting aeration was a kind of unsteady periodic disturbing source, the water in the reservoir model was driven to oscillate up and down by the air-water two-phase flow, and the internal waves were then induced by this oscillation in the stratified fluid. From the point of inducing source, the aeration-induced internal wave can be classified into a kind of wake-generated internal wave. The amplitude of internal waves peaked when the releasing periods of air piston were within the range of 44.06~58.69s. The internal waves were unable to be induced continuously when the releasing periods of air piston were longer than 180s. The amplitudes and periods of internal waves tended to increase with the diameter of the outlet of the water-lifting aerator. The generation of internal waves was also influenced by the thickness of the thermocline. Under constant temperature gradient, the amplitudes and periods of internal waves tended to increase with the thickness of the thermocline.