MULTIPHASE FLOWS SIMULATION WITH THE PARTICLE FINITE ELEMENT METHOD AND ITS COMPARISON WITH EULERIAN ALTERNATIVES

GIMENEZ JUAN; AGUERRE HORACIO; MARQUEZ DAMIAN, SANTIAGO; NIGRO NORBERTO; IDELSOHN, SERGIO

San Carlos de Bariloche

Congreso; ENIEF 2014; 2014

CNEA - Centro Atomico Bariloche

p { margin-bottom: 0in; direction: ltr; color: rgb(0, 0, 0); text-align: justify; widows: 2; orphans: 2; }p.western { font-family: "Times New Roman",serif; font-size: 11pt; font-weight: bold; }p.cjk { font-family: "Times New Roman",serif; font-size: 11pt; font-weight: bold; }p.ctl { font-family: "Times New Roman",serif; font-size: 10pt; }a:link { color: rgb(0, 0, 255); } Abstract.The latest version of the Particle-Finite Element Method (PFEM), which incorporates the novelexplicit integration strategy named eXplicit Integration of Velocity and Acceleration followingStreamlines (X-IVAS), has proven to be fast and accurate to solve homogeneous flows, mainly thanks tothe possibility of using large time-steps. In this work the extension of this strategy to solve multiphaseflows is presented, where the calculation of the interface evolution is of fundamental importance.In Eulerian formulations, one of the most used strategies to determine the interface position is theadvection of an indicator function. This approach is followed, by example, in the Volume of Fluid (VoF)technique, which can add limiters as a method of guaranteeing boundedness and/or sharpness of phase-fractions. On the other hand, Lagrangian frames use typically marker particles. In the case of PFEM, thesame set of particles transported for flow calculation allows to carry a marker function to determinate theinterface position without any extra cost. In order to compare the accuracy of PFEM interface evolutionstrategy with the Eulerian one implemented in the widely used OpenFOAM ® suite, several classical testsare presented.In addition to capture the sharpen interface evolution, PFEM algorithm includes the use of an enrichedfinite element space to avoid spurious solutions due to the discontinuity of pressure gradients, which alsorequires some changes in the streamline integration strategy. The description of those improvements arealso presented in this work. Finally the PFEM algorithm is tested for a number of problems involvingfree surface flows with different ratio between the densities and viscosities of the fluids involved. Theaccuracy of the results are compared with reference ones, focusing in the capability of using large time-steps in contrast with Eulerian solvers, including those with implicit phase-fractions advection treatment,represented by the OpenFOAM ® suite.