Direct numerical simulations of turbulent jets: vortex-interface-surfactant interactions
Abstract
We study the effect of insoluble surfactants on the spatio-temporal evolution of turbulent jets. We use three-dimensional numerical simulations and employ an interface-tracking/level-set method that accounts for surfactant-induced Marangoni stresses. The present study builds on our previous work (Constante et al., 2021, J. Fluid Mech., 922, A6) in which we examined in detail the vortex-surface interaction in the absence of surfactants. Numerical solutions are obtained for a wide range of Weber and elasticity numbers in which vorticity production is generated by surface deformation and surfactant-induced Marangoni stresses. The present work demonstrates, for the first time, the crucial role of Marangoni stresses, brought about by surfactant concentration gradients, in the formation of coherent, hairpin-like vortex structures. These structures have a profound influence on the development of the three-dimensional interfacial dynamics. We also present theoretical expressions for the mechanisms that influence the rate of production of circulation in the presence of surfactants for a general, three-dimensional, two-phase flow and highlight the dominant contribution of Marangoni stresses.
Cite
@article{arxiv.2207.05795,
title = {Direct numerical simulations of turbulent jets: vortex-interface-surfactant interactions},
author = {C. R. Constante-Amores and T. Abadie and L. Kahouadji and S. Shin and J. Chergui and D. Juric and A. A. Castrejon-Pita and O. K. Matar},
journal= {arXiv preprint arXiv:2207.05795},
year = {2023}
}