In this work, a combination of a spin-coating device and a noninvasive planar laser-induced fluorescence technique is realized for characterization of the interaction of sprays with thin wall films. This system enables investigation of resulting film topography and concentration fields after interaction of binary systems (different liquids for spray and film) in dependency of operating conditions. It can be used for the first time to distinguish between wall film liquid and spray liquid in the residual footprint of the interaction to better understand the underlying physical processes of liquid removal and deposition processes. In this first-time study, the interaction of an automotive spray (ECN Spray-B) with an 8.4 μm wall film is investigated for atmospheric conditions and different injection pressures and energizing durations. For each case, a complete removal of wall film fluid can be observed in the center of the impingement zone. The wall film liquid is collected in a characteristic rim around the impingement center. With increasing injection pressure, a flattening of the rim and a higher removal rate of wall film liquid is found. This effect is possibly caused by the increased shear acting on the liquid surface or by increased inertia forces due to a stronger impingement of the spray.

中文翻译：

---

平面激光诱导的荧光在喷涂壁膜相互作用过程中对液体去除和沉积的量化

在这项工作中，将旋涂设备与非侵入性平面激光诱导荧光技术相结合，可以表征喷雾剂与薄壁膜之间的相互作用。该系统能够根据操作条件，在二元系统（喷雾和薄膜的不同液体）相互作用后研究所得薄膜的形貌和浓度场。它可以首次用于在交互作用的残留足迹中区分壁膜液体和喷涂液体，以更好地了解液体去除和沉积过程的潜在物理过程。在这项首次研究中，针对大气条件，不同的注射压力和通电时间，研究了汽车喷雾剂（ECN Spray-B）与8.4μm壁膜的相互作用。对于每种情况，在撞击区域的中心可以观察到壁膜流体的完全清除。壁膜液体被收集在撞击中心周围的特征边缘中。随着注射压力的增加，发现边缘变平并且壁膜液体的去除率更高。这种作用可能是由于作用在液体表面上的剪切力增加或由于喷雾冲击力增加而导致的惯性力增加所致。