Abstract In this study, a series of experiments are performed to investigate the mixing and stratification of buoyancy-driven flows in a narrow inclined tank. The buoyancy-driven flow is produced by continuously releasing dense brine into an inclined tank filled with fresh water. Two distinct mixing regimes are identified. In one of the regimes, fresh water enters the tank because of the negative pressure induced by the brine plume. In the other regime, the fresh water inflow is mainly caused by the stack effect. A light attenuation technique is used to measure the density stratification and distribution in the tank. The effects of the buoyant source volume flow rate, source buoyancy flux, and source location on the mixing and stratification are investigated. The results indicate that the mixing between the buoyant and ambient fluids is strengthened by the increase in the source volume flow rate and the height difference between the source location and the lower end of the tank. However, the current downstream of the source becomes more stratified as the source buoyancy flux increases. A dimensionless parameter, λ , is proposed to evaluate the overall mixing intensity in the tank. As λ increases, the flow changes from a bidirectional one to a unidirectional one. The evolution of reduced gravity along the longitudinal direction is also investigated. The results indicate that fresh water is entrained into the brine layer if the thickness of the brine layer is less than the tank height. Otherwise, the reduced gravity remains constant along the longitudinal direction of the tank.

中文翻译：

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窄斜槽内连续浮力源产生的浮力驱动流混合分层实验研究

摘要 在这项研究中，进行了一系列实验来研究窄斜槽中浮力驱动流的混合和分层。浮力驱动的流动是通过将浓盐水连续释放到充满淡水的倾斜罐中来产生的。确定了两种不同的混合方案。在其中一种情况下，由于盐水羽流引起的负压，淡水进入水箱。在另一种情况下，淡水流入主要是由烟囱效应引起的。使用光衰减技术来测量储罐中的密度分层和分布。研究了浮力源体积流量、源浮力通量和源位置对混合和分层的影响。结果表明，随着源体积流量的增加以及源位置与罐下端之间的高度差，浮力流体和环境流体之间的混合得到加强。然而，随着源浮力通量的增加，源下游的电流变得更加分层。建议使用无量纲参数 λ 来评估罐中的整体混合强度。随着 λ 的增加，流动从双向变为单向。还研究了沿纵向方向减小的重力的演变。结果表明，如果盐水层的厚度小于储罐高度，淡水就会被夹带到盐水层中。否则，减小的重力沿罐的纵向保持恒定。