Predicting spray carry over through computational modelling

喷雾无处不在，可用于将材料(如油漆、农用化学品、药品、个人护理产品)输送到表面(如农作物、织物、皮肤)。喷雾过程很复杂，包括以下物理问题：(1)离开喷嘴时连续流动的(配制)液体分解成(2)离散液滴(喷雾)；(3)推进剂的蒸发；(4)液滴/颗粒向表面的传输；(5)液滴/颗粒撞击、粘合或反弹进入将物质带离表面的不断发展的流动中。提出了一种建模方法，它将使人们能够更好地理解描述喷洒到表面上的液滴/颗粒的命运的控制参数。拟议的方法将重点放在个人护理产品上，在这些产品中，颗粒物携带到空气中会导致呼吸不适。这项工作的一个特殊特点是，喷雾是一种复杂的配方产品，在撞击点将是形成功能涂层的颗粒和油的混合物，载液负责从材料中蒸发推进剂。此外，喷雾指向的表面的形状相对复杂，也将负责气流(从而传输)的演变。

Spraying is ubiquitous and finds application within delivery of materials (e.g. paints, agrochemicals, pharmaceuticals, personal-care products) to surfaces (e.g. crops, fabrics, skin). The spraying process is complex and includes physics around (i) a breakup of a (formulated) liquid from a continuous stream on leaving the spray-nozzle into (ii) discrete droplets (the spray) (iii) evaporation of propellant (iv) transport of droplet/particles to surfaces and (v) impact, adhesion or bounce of droplets/particulate into the evolving flow that carries material away from the surface. A modelling approach is proposed which will allow a better understanding of the controlling parameters that describe the fate of droplets/particles sprayed onto surfaces. The proposed approach will focus on personal care products where carryover of particulates into the air can cause respiratory discomfort. A particular feature of this work is that the spray is a complex formulated product and at the point of impact will be a mix of particulates and oils that form the functional coating, with the carrier fluid responsible for the propellant having evaporated from the material. Also, the shape of the surface to which the spray is directed is relatively complex and will also be responsible for how the airflow (and thus the transport) evolves.