Oscillatory states in thermal convection of a paramagnetic fluid in a cubical enclosure subjected to a magnetic field gradient

We report experimental and numerical studies of combined natural and magnetic convection of a paramagnetic fluid inside a cubical enclosure heated from below and cooled from above and subjected to a magnetic field gradient. Values of the magnetic field gradient are in the range 9?|grad|b0|2|?900 T2/m for imposed magnetic field strengths in the...

Overlap statistics of cumuliform boundary-layer cloud fields in large-eddy simulations

Overlap statistics of cumuliform boundary-layer clouds are studied using large-eddy simulations at high resolutions. The cloud overlap is found to be highly inefficient, due to the typical irregularity of cumuliform clouds over a wide range of scales. The detection of such inefficient overlap is enabled in this study by i) applying fine enough...

'T-RANS' simulation of deterministic eddy structure in flows driven by thermal buoyancy and Lorentz force

The paper reports on the application of the Time-dependent Reynolds-Averaged Navier-Stokes (T-RANS) approach to analysing the effects of magnetic force and bottom-wall configuration on the reorganisation of a large coherent structure and its role in the transport processes in Rayleigh-Benard convection. The large-scale deterministic motion is...

Formulation of the Dutch Atmospheric Large-Eddy Simulation (DALES) and overview of its applications

The current version of the Dutch Atmospheric Large-Eddy Simulation (DALES) is presented. DALES is a large-eddy simulation code designed for studies of the physics of the atmospheric boundary layer, including convective and stable boundary layers as well as cloudy boundary layers. In addition, DALES can be used for studies of more specific cases,...

Controls on precipitation and cloudiness in simulations of trade?wind cumulus as observed during RICO

Twelve large?eddy simulations, with a wide range of microphysical representations, are compared to each other and to independent measurements. The measurements and the initial and forcing data for the simulations are taken from the undisturbed period of the Rain in Cumulus over the Ocean (RICO) field study. A regional downscaling of...

Numerical and Experimental Study of Electromagnetically Driven Vortical Flows

The paper reports on numerical and experimental investigations of electromagnetically driven vortical flows of an electrically conductive fluid in a generic setup. Two different configurations of permanent magnets are considered: a 3-magnet configuration in which the resulting Lorentz force is focused in the wall-boundary layers, and a 2-magnet...

Tackling complex turbulent flows with transient RANS

This article reviews some recent applications of the transient-Reynoldsaveraged Navier–Stokes (T-RANS) approach in simulating complex turbulent flows dominated by externally imposed body forces, primarily by thermal buoyancy and the Lorentz force. The T-RANS aims at numerical resolving unsteady (semi-) deterministic vortical structures in flows...

Numerical analysis of blood flow in realistic arteries subjected to strong non-uniform magnetic fields

The paper reports on a comprehensive mathematical model for simulations of blood flow under the presence of strong non-uniform magnetic fields. The model consists of a set of Navier–Stokes equations accounting for the Lorentz and magnetisation forces, and a simplified set of Maxwell’s equations (Biot–Savart/Ampere’s law) for treating the imposed...

Suitability of quantum cascade laser spectroscopy for CH4 and N2O eddy covariance flux measurements

A quantum cascade laser spectrometer was evaluated for eddy covariance flux measurements of CH4 and N2O using three months of continuous measurements at a field site. The required criteria for eddy covariance flux measurements including continuity, sampling frequency, precision and stationarity were examined. The system operated continuously at...

Chemical Vapor Deposition: It's not just Chemistry

Thermometry for turbulent flames by coherent anti-Stokes Raman spectroscopy with simultaneous referencing to the modeless excitation profile

An optimal system for temperature measurements by coherent anti-Stokes Raman spectroscopy (CARS) in turbulent flames and flows is presented. In addition to a single-mode pump laser and a modeless dye laser, an echelle spectrometer with a cross disperser is used. This system permits simultaneous measurement of the N2 CARS spectrum and the...