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A method to predict sub-filter shear-induced velocities on a liquid-gas phase interface for use in a dual scale LES model is presented and compared against prior work on Vortex Sheet methods. The method reconstructs the sub-filter velocity field in the vicinity of the interface by employing a vortex sheet at the interface location. The vortex sheet is transported by an unsplit geometric volume and surface area advection scheme with a Piecewise Linear Interface Construction (PLIC) representation of the material interface. At each step, the vorticity field is constructed by evaluating a volume integral of the vortex sheet and a numerical spreading parameter near the liquid-gas interface. A Poisson equation can then be constructed and solved for the vector potential; the self-induced velocities due to the vortex sheet are subsequently evaluated from the vector potential. The described vortex sheet method is tested and compared against prior literature. 

A method to predict sub-filter shear-induced velocities on a liquid-gas phase interface for use in a dual scale LES model is presented. The method reconstructs the sub-filter velocity field in the vicinity of the interface by introducing a vortex sheet at the interface. The vortex sheet is transported by an unsplit geometric volume and surface area advection scheme with a Piece- wise Linear Interface Construction (PLIC) representation of the material interface. At each step and desired location the shear-induced velocities can be calculated by integrating the vortex sheet and other relevant quantities over the liquid-gas surface with the sub-grid velocity recon- struction limited to a small number of cells near the phase interface. The vortex sheet method is tested and compared against prior literature. 

A method to predict sub-filter shear-induced velocities on a liquid-gas phase interface for use in a dual scale LES model is presented. The method reconstructs the sub-filter velocity field in the vicinity of the interface by introducing a vortex sheet at the interface. The vortex sheet is transported by an unsplit geometric volume and surface area advection scheme with a Piecewise Linear Interface Construction (PLIC) representation of the material interface. At each step and desired location the shear-induced velocities can be calculated by integrating the vortex sheet and other relevant quantities over the liquid-gas interface with the sub-grid velocity reconstruction limited to a small number of cells near the phase interface. The vortex sheet method is tested and compared against prior literature. 

A method to compute sub-filter velocities due to shear induced instabilities on a liquid-gas interface for use in a dual scale LES-DNS model is presented. The method reconstructs the sub-filter velocity field as the sum of a prescribed base velocity profile and a perturbation velocity field determined by the Orr-Sommerfeld equations. The base velocity profile is approximated as an error function appropriately scaled with flow parameters, and the perturbation velocity field is computed by solving the Orr-Sommerfeld equations with appropriate boundary and interface conditions. The perturbation velocities of the Orr-Sommerfeld equations are expanded into Chebyshev polynomials to create a linear eigenvalue problem as outlined by Schmid and Henningson (2001). Finally the eigenvalue problem is solved using a standard linear algebra package and used to evaluate the perturbation velocities. The Chebyshev method is tested under a variety of flow parameters and initial interface disturbances. Results are presented and compared against prior literature and asymptotic solutions.