Advective transport in the ocean fundamentally is Lagrangian in nature. At model grid scales, this transport is parameterized by eddy or turbulent exchange coefficients in analogy to molecular diffusion. Nevertheless, much of the transport is by advection on scales larger than the grid cell yet smaller than basin scale. Moreover, flow at these scales tends to be nonstationary in time and irregu...

Observed long-term warming trends in the Southern Ocean have been interpreted as a sign of increased poleward eddy heat transport or of a poleward displacement of the entire Antarctic Circumpolar Current (ACC) frontal system. The two-decade-long record from satellite altimetry is an important source of information for evaluating the mechanisms governing these trends. While several recent studie...

A High Temperature Gas-cooled Reactor (HTGR) is one of the renewed reactor designs to play a role in nuclear power generation. This reactor design concept is currently under consideration and development worldwide. The combination of coated particle fuel, inert helium gas as coolant and graphite moderated reactor makes possible to operate at high temperature yielding a high efficiency. In this ...

Coherent sets in dynamical systems are regions in phase space that optimally "carry mass" with them under the system's evolution, so that these regions experience minimal leakage. The dominant tool for determining coherent sets is the transfer operator, which provides a complete description of Lagrangian mass transport. In this work, we combine existing transfer operator methods with a windowin...

Large eddy simulations in a wall bounded domain are conducted in order to study the kinematic structure of premixed turbulent flame. The linear model presents a prospect of isolating the effects of each of the physical mechanisms that underly turbulent combustion. In the present study, we investigate the flame structure in the absence of thermodyamic effects such as heat release using this mode...

A Large-Eddy Simulation of several cycles of a spark-ignition engine with port fuel injection has been performed. The investigated engine is a modified Rotax-engine with one cylinder and four valves, built and measured (Heidenreich, Private communication) by the Institute of Reciprocating Engines of the University of Karlsruhe (IFKM). A recently modified (Magagnato et al., 2008) progress variab...

Articles you may be interested in Partially integrated transport modeling method for turbulence simulation with variable filters Development of large eddy simulation for modeling of decaying compressible magnetohydrodynamic turbulence A dynamic flame surface density model for large eddy simulation of turbulent premixed combustion The effect of axisymmetric contraction and expansion on isotropic...

The dynamical equations of atmospheric flow are written using potential vorticity as the meridional coordinate and potential temperature as the vertical coordinate. Within this system, the atmosphere is divided into undulating tubes bounded by isentropic and constant potential vorticity surfaces, and, under adiabatic and frictionless conditions, the air moves through the tubes without penetrati...

[1] Most parameterizations used in Large Eddy Simulations of the atmospheric boundary layer are based on the assumption that subgrid-scale fluxes are aligned against spatial gradients of transported quantities (down-gradient closures). Based on field experiments, we determine the distribution and most probable relative orientations of the subgrid-scale (SGS) heat flux relative to parameterizati...

[1] The Tasman Sea is unique characterised by a strong seasonal western boundary current that breaks down into a complicated field of mesoscale eddies almost immediately after separating from the coast. Through a 16-year analysis of Tasman Sea eddies, we identify a region along the southeast Australian coast which we name ‘Eddy Avenue’ where eddies have higher sea level anomalies, faster rotati...