Industrial fluid mechanics relevant to paper and sprays

与造纸和喷雾相关的工业流体力学

• 批准号: 46520-2011
• 负责人: Green, Sheldon
• 金额: $ 2.33万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568973
• 关键词: Industrial; fluid; mechanics; relevant; paper

Over the past few years we have developed increasingly accurate numerical models of the single phase flow through a papermachine forming fabric. We propose to validate these models by carrying out PIV measurements of the flow through a scale model of a forming fabric. We also plan to expand on these models by including fibre interactions with the forming fabric. Each fibre in the flow will be modeling as a strand of linked spheroids, and the dynamics of the fibres in the forming-fabric flow will be studied. We plan to validate the numerical models by comparison with experimental observations of the interaction of a single fibre with a cylinder surface, which is a simple representation of one filament in a forming fabric. We will study the range of fibre orientations and positions for which a fibre will be hung up on a cylinder. The spraying of liquids onto a solid substrate is important industrially but faces many technical challenges. We have recently developed a new approach to spraying that has significant merit when uniformity of coverage is not an issue (e.g., when the spray material will subsequently be spread by other means). In this approach, the liquid to be applied is formulated to be highly viscous and elastic, and a pressure atomizer is used for application, similar to squeezing toothpaste from a tube. The impaction of this high speed column of fluid on a moving surface will be explored in two facilities. At lower speeds (up to 100 km/hour) a novel air cannon linear track we have developed will be used, and at higher speeds (up to 250 km/hour) we will develop a new "propeller-like" test facility. A variety of Newtonian and non-Newtonian fluids will be tested. The impaction process will be studied as a function of liquid column diameter, liquid physical characteristics, liquid impact velocity, surface roughness, and surface wettability. Recent experiments have shown that the surrounding air has an effect on the deposition or splash of individual droplets. We plan to repeat such experiments in a custom facility for studying liquid column impaction at low air pressure.

在过去的几年里，我们已经开发出越来越精确的数值模型的单相流通过造纸机成形织物。我们建议通过对成形织物的比例模型进行PIV测量来验证这些模型。我们还计划通过包括纤维与成形织物的相互作用来扩展这些模型。在流中的每一个纤维将建模为一个链接的球体链，并在成形织物流中的纤维的动力学将被研究。我们计划通过与实验观察的单纤维与圆柱体表面的相互作用进行比较来验证数值模型，圆柱体表面是成形织物中的一根长丝的简单表示。我们将研究纤维的取向范围和纤维在圆柱体上的悬挂位置。 将液体喷射到固体基底上在工业上是重要的，但面临许多技术挑战。我们最近开发了一种新的喷洒方法，当覆盖均匀性不是问题时，该方法具有显著的优点（例如，当喷射材料随后将通过其它方式散布时）。在这种方法中，待涂抹的液体被配制成高粘性和弹性的，并且压力雾化器用于涂抹，类似于从管中挤出牙膏。将在两个设施中探索这种高速流体柱在移动表面上的冲击。在较低的速度（高达100公里/小时），我们开发的一种新型的空气炮线性轨道将被使用，在较高的速度（高达250公里/小时），我们将开发一种新的“螺旋桨式”测试设备。将测试各种牛顿和非牛顿流体。冲击过程将作为液柱直径，液体物理特性，液体冲击速度，表面粗糙度和表面润湿性的函数进行研究。最近的实验表明，周围的空气对单个液滴的沉积或飞溅有影响。我们计划在一个定制的设备中重复这样的实验，以研究低气压下的液柱碰撞。