DEVELOPMENT OF A SPREAD SUBMODEL FOR SPRAY/WALL IMPACTION

In this paper, a new spray/wall impingement model is developed and tested. This model is based on the momentum conservation law and experimental observations. A new formula is derived for the motion of a droplet in the spread regime of the wall impaction model based on analysis of droplet evolution dynamic with consideration of surface tension, and viscous and drag forces. Following the experimental findings, the new model consists of four representative regimes which are stick, rebound, spread, and splash. To validate the new model, numerical calculations are made using several experimental cases as well as a nonevaporating impinging spray on a flat wall. The results of the model are compared with the experimental data of spray tip penetration and wall impaction. Predicted spray penetration matches up with the experimental data. The results show that the new model generally predicts the spread and splash behavior, local droplet velocity, and size better than the existing models. In addition, this model is able to improve prediction of overall and internal structure of wall spray in comparison to existing models.