Mixing Mechanism of Internal Hydraulic Jump

(1)内水跃中的回流辊研究了双层流动系统中内水跃的水力和湍流混合特性。实验结果表明，内跳跃的特点是在跳跃界面下有一个与内跳跃流动方向相反的回流辊。虽然它的起源是相似的辊在一个开放的渠道水跃中观察到的，再循环辊的大小和反向流量被证明是非常大的。此外，由于两层流体的混相密度差，使滚筒形成了与跳跃流相联系的大尺度环流形式。因此，它直接防止了内部跳跃夹带环境流体。尽管存在特征循环辊，但在分析内跳时没有考虑它。提出了一个动量原理模型， 关于我们 循环辊的性能。该模型被证实预测的混合性能的内部跳跃的上游密度弗劳德数的函数合理，这还没有被任何现有的分析模型解释。(2)径向内水跃本文对渐扩通道内径向内水跃的流动特性进行了理论和实验研究。逐渐扩大的渠道遵循河口几何形状的例子。通过假设跳跃剖面为抛物线形，将动量原理推广到跳跃的扩展段。理论结果与实验结果进行了比较。(3)代数应力模型（ASM）在平面浮力射流中的应用为了准确地考虑重力场和自由表面对湍流结构的阻尼作用，本文建立了一个用于预测浮力射流特性的代数应力模型。ASM解决方案测试产生了良好的协议与测量的流动发展和湍流卷吸的平面浮力表面射流。目前正在努力将ASM应用于内部液压接头。少

(1) Recirculating Roller Observed in Internal Hydraulic JumpThe hydraulic and turbulent mixing properties of an internal hydraulic jump were investigated in a two-layered flow system. Experimental results indicated that the internal jump was characterized by a recirculating roller flowed beneath the jump interface in the opposite direction to the internal jump flow. Although its origin was similar to the roller observed in an open channel hydraulic jump, the size and reverse flow rate of the recirculating roller were shown to be remarkably large. Besides, the roller made a large scale circulation form in connection with the jump flow because of the miscible density difference of two-layered fluids. Consequently, it directly prevented the internal jump from entraining ambient fluid. In spite of the existence of the characteristic recirculating roller, it had not been taken into consideration in analyzing an internal jump. A momentum principle model were presented in due consideration of … More the recirculating roller properties. This model was confirmed to predict the mixing properties of the internal jump as a function of the upstream densimetric Froude number reasonably, which had not been explained by any existing analytical model.(2) Radial Internal Hydraulic JumpThe flow properties of a radial internal jump within a gradually expanding channel are examined treoretically and experimentally. The gradually expanding channel follows an example of an estuary geometry. The momentum principle is extended to the expanding sections of jump by assuming that the jump profile is parabolic in shape. Theoretical results are compared with experimental ones.(3) Application of Algebraic Stress Model (ASM) to Plane Buoyant Surface Jet An algebraic stress model is developed to predict the behaviours of buoyant surface discharges for taking account of the damping effects of the gravitational field and the free surface on turbulence structure accurately. The ASM solution tested produces a good agreement with measurements on the flow development and turbulent entrainment of plane buoyant surface jets. Efforts to apply the ASM into an internal hydraulic jum are presently ongoing. Less