Numerical and experimental investigation of jet atomization at low We number*

Dispersed phase flows are widely observed in industrial and everyday life applications, studying their characteristics is essential for controlling and optimizing.

We are interested in water infiltration inside the awning box of a car vehicle. It occurs either as jet atomization in stagnant air (Heating, Ventilation, and Air-Conditioning or HVAC off) and as a jet sheared by air (HVAC on). The industrial objective is twofold, (i) preventing water ingestion by the HVAC (ii) optimizing time and resources in the vehicle conception.

We propose to study the atomization of a cylindrical jet under the same flow conditions (water and air) observed in the awning box. We focus on low water Webber number (We=ρU²D/σ) where we observe typically dripping, jetting, and first wind-induced breakup regimes. The airflow starts from stagnant air at zero velocity to a maximum of 10 m/s, which remains relatively low compared to similar studies. We study the evolution of the jet breakup length, the temporal statistic of drops (bulk and satellite), and the trajectory of the jet and drops. We combine approaches: a numerical using a CFD Basilisk code which solves the N-S equations with Adaptive Mesh Refinement (AMR), and an experimental by setting an experimental setup of the problem.