DOI: 10.1615/TSFP9
DIRECT NUMERICAL SIMULATION OF SURFACE TENSION EFFECTS ON INTERFACE DYNAMICS AND ENERGY TRANSFER IN TURBULENCE
要約
The interaction between turbulence and surface tension is studied through direct numerical simulation of a canonical multiphase flow. An initially flat interface is inserted into a triply periodic box of decaying homogeneous isotropic turbulence, simulated for a variety of turbulent Reynolds and Weber numbers on mesh sizes of 5123 and 10243. Unity density and viscosity ratios are used in order to isolate the interaction between fluid inertia and the surface tension force. Interface height correlations and liquid volume fraction variance spectra are used to study the spatial scales of corrugations on the interface. A case with zero surface tension is first considered, yielding a passive interface that moves materially with the fluid. The power spectral density of the liquid volume fraction variance follows a κ−1 scaling, where κ is the wavenumber, which is consistent with dimensionality arguments. In the presence of surface tension, this corrugation spectrum follows a κ−1 scaling for large scales, but then deviates at a length scale wich corresponds to the critical radius. A spectral analysis of liquid volume fraction variance transfer is conducted, shedding light on the role played by surface tension in this process. Results will be used to deduce important ramifications for sub-grid scale models in large-eddy simulations of liquid-gas flows.