摘要
采用线性层结盐水发生装置以及喷嘴向下以重盐水注入盐水层结的方法,模拟线性层结盐水中羽流的发展过程;应用时间分辨粒子图像测速技术(PIV),研究线性层结盐水中羽流内部流场结构。羽流的发展过程可以定性地归纳为3个阶段:入射阶段、中性浮力层出现阶段和中性浮力层稳定阶段。实验结果显示:羽流流速从中心区域向边缘逐步递减;羽流在下沉到最大深度后回升到中性浮力层,并向四周扩散;在羽流内部及边界存在大量复杂的涡旋结构,说明在羽流发展的过程中,始终伴随着羽流与周围环境水体之间的掺混作用。重新拟合确定了羽流最大穿透距离公式中的量纲一常数C,取值为4.03。
The two-tank setup was employed to produce linearly stratified salt-water in laboratory tank. Laboratory experiments on buoyant plumes were undertaken by jetting dense salt-water downward into the linear stratification,aiming at investigating plume development in stratified salt-water. The time-resolving Particle Image Velocimetry（ PIV） approach was adopted to investigate the flow field through the entire plume development. Plume visualization showed three distinct stages of plume development,namely,the inflow stage,the producing stage of the neutral buoyant layer,and the stabilizing stage of the neutral buoyant layer. It was shown that flow velocity decreased from plume stem to edge. Instantaneous flow fields revealed there were complex vortices both near the plume boundary and inside the plume which indicated entrainments occurred throughout plume development. The experimental results agreed with the MTT（ Morton,Taylor and Turner） model in general,although with a slightly modified prefactor to the empirical formula. This paper contributes to plume investigations by adding supplemental data to small-scale plume regime of the MTT model.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2016年第4期602-608,共7页
Advances in Water Science
基金
国家自然科学基金资助项目(41376095)
浙江省自然科学基金资助项目(LR16E090001)~~
