Volume of Fluid method for low-Mach-number compressible supercritical liquid jet

Jordi Poblador Ibanez, William Sirignano
2021 International Conference on Liquid Atomization and Spray Systems (ICLASS)  
A two-phase, low-Mach-number compressible flow solver is proposed. Density variations are linked to changes in composition and temperature rather than pressure. The interface is tracked using a split Volume-of-Fluid method generalized for the case where the liquid velocity is not divergence-free and both phases exchange mass across the interface. A sharp interface is maintained by using a Piecewise Linear Interface Construction (PLIC). At supercritical pressures, the dissolution of lighter gas
more » ... pecies into the liquid phase is enhanced and vaporization or condensation can happen simultaneously in different locations along the interface. Mass is conserved to machine-error precision in the limit of incompressible liquid. The numerical cost of solving two-phase supercritical flows increases substantially because: a) a thermodynamic model is used to determine fluid properties; b) local phase equilibrium and jump conditions are solved together at each interface cell; and c) phase-wise values for certain variables (e.g., velocity) are obtained via extrapolation techniques. To alleviate the increase in numerical cost, the pressure Poisson equation (PPE) is split into a constant coefficient part (implicit) and a variable coefficient part (explicit) and solved using a Fast Fourier Transform (FFT) method. Various tests at high pressures are performed to show the accuracy and viability of the present approach: one-dimensional unsteady flow, two-dimensional capillary wave and planar jet.
doi:10.2218/iclass.2021.5914 fatcat:z2ndcl2wa5bcroyb3ssye2n7ea