Purely dissipative eddy–viscosity subgrid models have proven very successful in large–eddy simulations (LES) at moderate resolution. Simulations at coarse resolutions where the underlying assumption of small–scale universality is not valid, warrant more advanced models. However, non-eddy viscosity models are often unstable due to the lack of sufficient dissipation. This paper proposes a simple ...

Abstract Monin–Obukhov similarity theory (MOST) is a well-tested approach for specifying the fluxes when roughness surfaces are homogeneous. For flow over waves (inhomogeneous surfaces), phase-averaged length scales often prescribed through models based on wave characteristics and wind speed. However, such approaches lack generalizability different ages steepnesses due to reliance model coeffic...

The present paper investigates monitoring of fatigue cracks of a metal structure using an eddy current micro sensor. Fatigue cracks tend to occur at bolt-jointed structures on an aircraft. In order to detect the damage quantitatively, a kind of change-prone micro eddy current sensor is designed and fabricated with flexible printed circuit board (FPCB) technology. A forward semi-analytical model...

An intense subsurface chlorophyll enhancement was found repeatedly within the core of a modewater eddy during a 2-month period. Two controls on chlorophyll concentrations in this deep chlorophyll maximum (DCM) layer are noted: chlorophyll concentration is controlled by nutrients at low nutrient concentrations and by light when nutrients are saturating. To synthesize these results, a simple one-...

Oceanic vortices have been the subject of several experimental and theoretical studies. They play a key role in the energy budget of the global ocean. A better understanding of their physics, (e.g. interaction with the mean currents) would improve our knowledge of the ocean circulation. Satellite altimeter data are used to detect, track and analyze the strong anticyclonic eddies generated by th...

The propagation of light through slab-like photonic crystals (PCs) is frequently described in terms of effective indices (effective index method EIM, cf. e.g. Refs. [1, 2, 3]). One replaces the actual 3-D structure by an effective 2-D permittivity, given by the propagation constants of the slab modes of the local vertical refractive index profiles. Though the approach is being described usually...

Evolution-in-materio (EIM) is the manipulation of a physical system by computer controlled evolution (CCE). It takes the position that to obtain useful functions from a physical system one needs to apply highly specific physical signals and place the system in a particular physical state. It argues that CCE is an effective methodology for doing this. One of the potential advantages of this is t...

An eddy viscosity model can be used as a computationally tractable alternative to that of the Navier-Stokes equations. Model errors immediately become a concern when considering such an approach, and quantifying this error is essential to understanding and using model predictions within an engineering design process. In this paper, sensitivity analysis is presented for a subgrid eddy viscosity ...

We present a dynamical spectral model for large-eddy simulation of the incompressible magnetohydrodynamic (MHD) equations based on the eddy damped quasinormal Markovian approximation. This model extends classical spectral large-eddy simulations for the Navier-Stokes equations to incorporate general (non-Kolmogorovian) spectra as well as eddy noise. We derive the model for MHD flows and show tha...