A COUPLED FINITE VOLUME / MATERIAL POINT METHOD FOR COMPRESSIBLE GAS-LIQUID TWO-PHASE FLOWS FOR APPLICATION TO ATOMIZATION

The focus of this study is on developing a numerical methodology to coupled Lagrangian descriptions of liquids using Material Point Methods (MPM) with Eulerian finite volume formulations of compressible flow undergoing atomization. The MPM is based on a generalized interpolation material point (GIMP) using convected particle domain interpolation (CPDI). To couple the phases, a volume fraction based stratified flow description is introduced that enforces zero gas pressure gradient at the gas-liquid interface. 1D benchmark problems are presented to assess the accuracy of the coupling and to demonstrate the stratified flow coupling algorithm satisfies the pressure non-disturbance condition. 2D benchmarks show the interface reconstruction algorithm is second order accurate. Simulations of millimeter sized colliding 2D liquid rings are presented for assessing the limits of the interface reconstruction and sensitivity to gas coupling. Without gas coupling the rings undergo three stages of flow development associated with: 1) fluid jetting, 2) formation of horseshoe vorticies and 3) outer ring creation. With gas coupling, the horseshoe vorticies are suppressed from internal gas pressurization within the rings. Results show the interface reconstruction is able to reliably capture the inner and outer interfaces during all stages of impact - indicating the new coupling methodology is robust.