ID 44

Numerical study of interface reconstruction method in under-resolved regions of the flow for liquid jet primary breakup

 

Abstract:

Atomization of injected fuel in internal combustion (IC) engines and gas turbines plays a major role in the pollutant emissions. Due to the multiphase and multi-physical aspect of fuel spray atomization, experimental investigations proves challenging for studying liquid/gas interface in these devices. This motivates the need for high fidelity numerical simulations.

Commonly, volume of fluid (VOF) (Aulisa JCP 2003), level set (LS) (Desjardins JCP 2008; Herrmann Atom. Sprays 2011; Shinjo IJMF 2011) or their variants (Ménard IJMF 2007) have been used for liquid/gas interface reconstruction for such applications. A key point of these methods is geometrical properties computation which can fail in under-resolved regions of the flow due to incorrect computation of interface unit normal.

To this end, a numerical method for interface reconstruction is developed in this work called moment of fluid (MOF) method (Dyadechko JCP 2008; Li IJNMF 2015). MOF uses liquid volume fraction and centre of mass (COM) for interface reconstruction. Interface reconstruction in MOF require information only from the current computational cell and thus, the treatment for interior and boundary cells is identical. The liquid volume fraction is advected using directionally split algorithm (Weymouth and Yue JCP 2010) and the COM is advected using directionally split Eulerian Implicit-Lagrangian Explicit method. Results concern the comparison of interface reconstruction by MOF and CLSVOF method for various interface configurations pertaining to primary breakup of liquid jet in terms of accuracy, computational time consumption, and relevance of usage of method at specific regions of the flow.