ID 305

Pairwise Interaction Extended Point-Particle (PIEP) Model for droplet-droplet interaction in dense spray systems

 

Abstract:

Euler-Lagrange (EL) methodology is the common approach used to simulate the collective dynamics of a very large number of dispersed droplets in the mid region of a spray. Traditional point-particle models used in these EL simulations assume the force on a droplets to depend only on mean Reynolds number and the mean volume fraction. This approximation ignores interactions among the droplets at the microscale and therefore significantly under-predicts fluctuations in droplet velocity and feed-back forces, resulting in incorrect mesoscale structures and macroscale dispersion. In this study we investigate the extended point-particle force model and rigorously account for the hydrodynamic influence of the neighboring droplets. The model computes the drag and lift forces, and heat/mass transfer on each droplet by accounting for the precise location of few surrounding neighbors. We consider a hybrid approach that combines a physics-based modeling approach that is built upon the Faxen theorem with data-driven approach that relies on training data from fully-resolved simulations. The model is tested extensively for the cases of a random array of stationary and freely sedimenting particles. The overall objective of our project is to demonstrate multiphysics control of liquid sprays. The talk will also present the on-going simulation effort of a spray in the mid-field region, where the dispersed droplets in a turbulent flow is considered with the PIPE model. Mid-field control of spray using electrostatic and acoustic forcing will be systematically explored. This study is part of a multi-disciplinary university research initiative (MURI) funded by the Office of Naval Research to experimentally and computationally explore multi-physics spray control.