To evaluate the accuracy of the lattice Boltzmann method with the zonal grid refinement for high Reynolds number turbulent flows, large eddy simulation of turbulent channel flows is carried out by the D3Q27 multiple-relaxation time lattice Boltzmann method with the imbalance-correction grid refinement method. Considering the continuity of the pressure and the momentum fluxes at the finer and co...

The effect of the spanwise discretisation on numerical calculations turbulent flow around a circular cylinder is systematically assessed at subcritical Reynolds number 10000 in frame three-dimensional large-eddy simulation. eddy-viscosity k-equation subgrid scale model implemented to evaluate unsteady field. Large-eddy simulation known be reliable method resolve such challenging field, however,...

We use a numerical model of Saturn’s thermosphere to investigate the flow of angular momentum from the atmosphere to the magnetosphere. The thermosphere model is driven by Joule heating and ion drag calculated from a simple model of the magnetospheric plasma flows and a fixed model of the ionospheric conductivity. We describe an initial study in which our plasma flow model is fixed and find tha...

We report results gained with a three-dimensional, semi-implicit, semi-spectral model of the shallow water equations on the rotating Earth that allowed one to compute the wind-induced motion in lakes. The barotropic response to unidirectional, uniform winds, Heaviside in time, is determined in a rectangular basin with constant depth, and in Lake Constance, for different values and vertical dist...

The accuracy of large-eddy simulations is limited, among others, by the quality of the subgrid parameterisation and the numerical contamination of the smaller retained flow structures. We review the effects of discretisation and modelling errors from two different perspectives. We first show that spatial discretisation induces its own filter and compare the dynamic importance of this numerical ...

This study aimed to highlight a general lack of clarity regarding the scale temporal averaging implicit in Ekman-type models. Under assumption time and depth-dependent eddy viscosity, we present an analytical Fourier series solution for wave-modified Ekman model. The depth dependence viscosity is based on K-Profile Parameterization (KPP) scheme. reproduces major characteristics diurnal variatio...

In the framework of the Gas-Power Conversion System for the Advanced Sodium Technological Reactor for Industrial Demonstration (ASTRID) project design, works done at CEA are focused on the design of the sodium-gas heat exchanger. Compact plate heat exchangers are indicated as the most suitable technology for such applications. An innovative compact heat exchanger geometry is proposed in this pa...

Stochastic coherent adaptive large eddy simulation SCALES is an extension of the large eddy simulation approach in which a wavelet filter-based dynamic grid adaptation strategy is employed to solve for the most “energetic” coherent structures in a turbulent field while modeling the effect of the less energetic background flow. In order to take full advantage of the ability of the method in simu...