Experimental and numerical investigations of multiphase jets

在许多工程应用中，都可以发现带有泥沙和气泡的射流。向环境水中注入空气(即气泡射流)通常用于加强湖泊和河流、废水处理、热交换器和工业反应堆的混合和曝气。在采矿作业、水力运输、疏浚材料处理以及工业和生活废水排放中，可以发现满载沙粒的射流(即泥浆射流)。了解气泡或沙粒与环境水的动态相互作用对于合理设计和优化包括氧气扩散器和海洋排污口在内的工程系统具有重要意义。 对气泡射流进行了大量的实验研究，以测量气泡尺寸、比界面面积、气泡速度和周围水结构等参数的变化。早期对气泡射流的研究表明，气泡尺寸对气泡射流的混合性能有很大影响。泥浆射流也有许多工业和工程应用，如泥浆运输、海洋床盖、采矿作业、疏浚材料处理以及工业和生活废水的排放。了解泥沙颗粒与周围环境的动力相互作用对于合理设计和优化这些工程系统具有重要意义。根据流动形态的不同，沉积物可以通过管道/渠道输送，也可以通过喷嘴形成泥浆射流。沙粒与周围环境的动态相互作用还与沉积物的物理性质有关，如沉积物的大小、形状、密度和浓度。 该计划试图了解不同相(即固、液和气相)之间的潜在机理，并试图增强该领域的现有知识。将采用实验和数值两种方法来研究这一问题。将培训高素质的人员从事这一领域的研究，并监测自然界和工业的现有系统。数值模拟是研究含沙气泡射流动力学的一种合适选择。该程序可以使用商业建模包或基于研究的开源模型。为了进行设计和优化，可以使用经过验证的模型来模拟许多场景，以研究其他流程配置。可以为基于研究的代码开发子例程，以增强模型的能力，以便在该领域进行更准确的模拟。

Sediment-laden and bubbly jets can be found in many engineering applications. Air injection into ambient water (i.e., bubbly jets) has been commonly used to enhance mixing and aeration in lakes and rivers, wastewater treatment, heat exchanger and industrial reactors. Sand-laden jets (i.e., slurry jets) can be found in mining operations, hydro-transport, dredging material disposal, and discharge of industrial and domestic wastewater. Understanding the dynamic interactions of air bubbles or sand particles with the ambient water are important for proper design and optimizing the engineering systems including oxygen diffusers and ocean outfalls. Extensive experimental investigations on bubbly jets have been carried out to measure the variations of bubble parameters such as bubble size, specific interfacial area, bubble velocity and ambient water structure. Early investigations of bubbly jets have shown that the mixing performance of bubbly jets is greatly influenced by the bubble size. Slurry jets have also many industrial and engineering applications, such as, slurry transport, marine bed capping, mining operations, dredging material disposal, and discharge of industrial and domestic wastewater. Understanding the dynamic interactions of the sediment particles and its ambient are important for proper design and optimizing those engineering systems. Depending upon the flow configurations, sediments can be transported through pipelines/channels or can be passed through a nozzle to form a slurry jet. Dynamic interactions of the sand particles and its ambient are also correlated with the physical characteristics of sediments such as sediment size, shape, density and concentration. This program attempts to understand the underlying mechanisms between different phases (i.e., solid, liquid and gas phases) and tries to enhance the existing knowledge in this field. Both experimental and numerical approaches are going to be used to study the problem. Highly qualified personnel will be trained to pursue research in this area and monitor the existing systems in both nature and industry. Numerical modeling can be a suitable choice to study the dynamics of sediment-laden and bubbly jets. Commercial modeling packages or research-based open source models can be used in this program. Many scenarios can be simulated using a validated model to study other flow configurations for designing and optimization purposes. Sub-routines can be developed for research-based codes to enhance the capability of models for more accurate simulations in this field.