Additional experiments with the slowly varying axisymmetric hurricane model described by Anthes are presented. Variable horizontal eddy viscosity coefficients are utilized to study circulations that result from an increased heating function and a heating function with a double maximum along the radial direction. Infrared radiative cooling is modeled for the clear tropical atmosphere following S...

An eddy viscosity model for two-dimensional breaking waves and its validation with laboratory experiments Zhigang Tian,1 Marc Perlin,2 and Wooyoung Choi1,3 1Division of Ocean Systems Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea 2Department of Naval Architecture and Marine Engineering, University of Michigan, Ann Arbor, Michigan, USA 3Department o...

The spectral vanishing viscosity (SVV) method has recently appeared of interest for the large-eddy simulation (LES) of turbulent flows. Here we show that the SVV-LES approach allows to easily compute turbulent quantities, like the dissipation rates of the turbulent kinetic energy or of the variance of a passive scalar and to clearly discern the subgrid and viscous contributions. Results obtaine...

In this paper, we provide a method of evaluating the efficacy of nonlinear subgridscale models for use in the large eddy simulation of incompressible viscous flow problems. We compare subgridscale “artificial” viscosity models using a posteriori error estimation and adaptive mesh refinement. Specifically, we compare α-Laplacian based subgridscale models and discuss the benefits and limitations ...

We extend a large-eddy simulation (LES) methodology, based on using the spectral vanishing viscosity (SVV) method to stabilize spectral collocation approximations, from the Cartesian to the cylindrical geometry. The capabilities of the SVV–LES approach are illustrated for two very different physical problems: (1) the influence of thermal stratification on the wake of a cylinder, and (2) the ins...

A non-hydrostatic code that numerically solves the unsteady, three-dimensional, primitive equations is used. Advanced models such as the dynamic mixed model and the dynamic eddy viscosity model are utilized to represent subgrid processes in the LES approach. A novel near-wall model has been developed so as to increase the Reynolds number of boundary flows to realistically large geophysical valu...

Abstract. Three-dimensional transonic flow over a delta wing is investigated using several turbulence models. The performance of linear eddy viscosity models and an explicit algebraic stress model is assessed at the start of vortex flow, and the results compared with experimental data. To assess the effect of transition location, computations that either fix transition aft of the leading edge o...

We use the mean-eld dynamo equations to show that spatially and temporally incoherent uctuations in the helicity in mirror-symmetric turbulence in a shearing ow can generate a large scale, coherent magnetic eld. We illustrate this eeect with simulations of a few simple systems. For statistically homogeneous turbulence we nd that the dynamo growth rate is roughly ?2=3 eddy ?1=3 shear N ?1=3 eddy...

The goal of this study is to compare the performances of the ensemble Kalman filter and a reduced-rank extended Kalman filter when applied to different dynamic regimes. Data assimilation experiments are performed using an eddy-resolving quasi-geostrophic model of the winddriven ocean circulation. By changing eddy viscosity, this model exhibits two qualitatively distinct behaviors: strongly chao...

In this paper, we study the classical problem of wind in steady atmospheric Ekman layer with constant eddy viscosity. Different from previous work, modify boundary conditions and derive explicit solution by using notation matrix cosine sine. For arbitrary height-dependent viscosity, get zero velocity acceleration at bottom layer. addition, uniqueness is shown dynamical properties are characteri...