An enhancement of vortex-motion damping in thin Pb/In superconducting films is obtained through coupling to an adjacent two-dimensional electron gas formed in a modulation-doped GaAs/AlGaAs heterostructure. This effect is observed by monitoring the power dissipation in the superconductor in the vortex state while increasing the density of the electron gas using a gate voltage. Quantitative agre...

Turbulent flows are intrinsic to many processes in science and engineering, and efforts to elucidate the physics of turbulence are of critical importance to many fields. However, ongoing efforts to achieve a fundamental understanding of the mechanisms of turbulent flow are hindered by the difficulty of quantifying the complex, nonlinear interactions between individual eddies in these flows. The...

This paper presents a series of dynamical states using an idealized three-dimensional general circulation model with gray radiation and latent heat release. Beginning with the case of radiative–convective equilibrium, an eddy-free two-dimensional state with zonally symmetric flow is developed, followed by a threedimensional state that includes baroclinic eddy fluxes. In both dry and moist cases...

[1] In this paper, by using a dynamic model with synoptic eddy and low-frequency flow (SELF) interaction, we show that the SELF feedback is of significant importance for the formation of the AO/NAO in both winter and summer. Although background storm activity is significantly weaker in summer than that in winter, the positive SELF feedback associated with the AO/NAO mode in summer can be as str...

The feasibility of using a commercial CFD code for large eddy simulation (LES) is investigated. A first test on homogeneous turbulence decay allows a fine-tuning of the eddy viscosity with respect to the numerical features of the code. Then, a flow over forward–backward facing step at Reynolds number Reh 1⁄4 1:7 10 is computed. The results found show good agreement with the new LDA data of Lecl...

The deposition of particles in fully-developed turbulent channel flow has been calculated using large eddy simulation of the incompressible Navier-Stokes equations. Calculations were performed for Reynolds numbers of 11,160 and 79,400 (based on bulk velocity and hydraulic diameter); subgrid-scale stresses were parameterized using the dynamic eddy viscosity model. Particle motion was governed by...

Aerodynamic noise produced by aerodynamic interaction between a cylinder (rod) and an airfoil in tandem arrangement is investigated using large eddy simulations. Wake from the rod convects with the flow, impinges of the airfoil to produce unsteady force which acts as a sound source. This rod-airfoil interaction problem is a model problem for noise generation due to inflow or upstream-generated ...

Large-eddy simulation of particle-laden turbulent channel flow is investigated for several subgrid models and Stokes numbers with the objective to investigate the accuracy of the subgrid models studied with respect to particle behavior. It is shown that the wall-normal particle velocity and particle velocity fluctuations are reduced compared to DNS, if the filtered fluid velocity calculated in ...

Today, whereas aeronautical CFD applications are mainly based on Reynolds Average Navier-Stokes modeling, Large Eddy Simulation (L.E.S.) is becoming more used for some of them. LES needs the instantaneous inlet velocity as turbulent inflow boundary conditions which motivates the implementation and validation of a synthetic turbulent inflow condition for LES. The so called "Synthetic Eddy Method...

Townsend’s attached eddy hypothesis states that the flow in the logarithmic region of wall-bounded turbulent flows will be dominated at the energy-containing scales by a hierarchy of eddies, whose corresponding velocity fields extend to the wall [20]. These eddies are assumed to be geometrically self-similar, differing from each other only in their size, which scales with their distance from th...