College of Humanities and Sciences Faculty Posters

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  Multiscale modeling of internal waves and turbulence at rough, realistic topography with SOMAR-LES

  Edward Santilli, Vamsi Chalamalla, Alberto Scotti, and Sutanu Sarkar

  The Stratified Ocean Model with Adaptive Refinement (SOMAR) is a modeling framework with the flexibility of adaptive mesh refinement (AMR) at localized regions with high gradients. Several test cases including the lock-exchange problem, solitary wave propagation, and internal tide generation have been previously considered to validate the method. Local refinement of the grid allows the solver to achieve highly accurate results with substantial reduction in computational cost. Recently, SOMAR-LES has been developed wherein a three-dimensional, body-conforming, Large Eddy Simulation (LES) model that resolves turbulent scales is coupled with SOMAR to accurately represent small scale turbulence as well as its effect on flow evolution at large scales. The coupling is two-way: the LES is driven with large scale forcing, and SOMAR receives feedback in the form of an eddy viscosity, diffusivity, and sub-grid scale fluxes. This novel multi-scale modeling technique is applied to study the near- and far-field baroclinic response when the oscillating barotropic tide interacts with underwater topography. Numerical simulations are currently being performed with SOMAR-LES to examine the flow at Kaena ridge, a steep supercritical generation site, where the topographic length scales are of O(100 km), and the barotropic forcing corresponds to a small outer excursion number (Ex ~ 0.01) and small Froude number (Fr ~ 0.006). The SOMAR-LES results will be used to quantify baroclinic energy conversion and internal wave properties such as the radiated wave flux and modal composition.