3. Surface tension problems solved with the Particle Finite Element Method using large time-steps

GIMENEZ JUAN; NIGRO NORBERTO; IDELSOHN, SERGIO; OÑATE EUGENIO

COMPUTERS & FLUIDS

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016

0045-7930

p { margin-bottom: 0.25cm; line-height: 120%; }In previous works[1, 2], the authors have presented an highly efficientextension of theParticle Finite Element Method, called PFEM-2, to solvetwo-phase flows. Themethodology which uses X-IVS[3] to treat convectionterms allowing largetime-steps was validated for problems where the gravityforces and/or theinertial forces dominate the flow. Although that is thetarget range ofproblems to solve with PFEM-2, most of real problems thatfall in thesecategories also includes other flow regimes in certain regions ofthe domain. Maybethe most common secondary regime is when the surfacetension dominates,as an example when drops or bubbles are released fromthe main flow, andthis feature must be taken into account in any completenumerical strategy.Attending to that,in this work the treatment of the surface tension to PFEM-2 is included.An implicit CSF methodology is employed togetherwith a couplingbetween the marker function with a Level Set functionto obtain a smoothrepresentation of the normal of the interface whichallows an accuratecurvature calculation. Examples for curvature calculationand isolated bubblesand drops are presented where the accuracy and thecomputationalefficiency are analyzed and contrasted with other numericalmethodologies.Finally, a simulation of a jet atomization is analyzed. Thiscase presents theabove mentioned features: it is a inertia-dominant flow witha surface tensionphenomena on drops and ligaments break up that can notbe neglected.