Information theory provides a concise systematic framework for measuring climate consistency and sensitivity for imperfect models. A suite of increasingly complex physically relevant linear Gaussian models with time periodic features mimicking seasonal cycle are utilized to elucidate central issues that arise in contemporary climate science. These include the role of model error, the memory of ...

to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

To reveal the inner mechanism of gas explosion dynamic behavior affected by gas equivalent concentration, a high speed Schlieren image system and flow field measurement technology was applied to record the gas explosion flame propagation and flame structure transition. The results show that a flame front structure transition occurs, followed by a flame accelerating propagation process. The lami...

The modeling of multiphase, turbulent flows and their dynamics has become increasingly important in many environmental, geophysical, and engineering applications. These areas require the use of models that can effectively represent both the multiphase and turbulent characteristics involved in the simulation. Due to the large increase in computational power required to both simulate multiphase a...

We study the large time asymptotic speeds (turbulent flame speeds sT ) of the simplified Hamilton-Jacobi (HJ) models arising in turbulent combustion. One HJ model is G-equation describing the front motion law in the form of local normal velocity equal to a constant (laminar speed) plus the normal projection of fluid velocity. In level set formulation, G-equations are HJ equations with convex (L...

Flamelets play an important role as subgrid models in large eddy simulations of turbulent flames: they are based on a one-dimensional steady asymptotic solution for the flame. The focus of the present study is to validate their use when unsteadiness and multidimensional effects are present, as to be expected for turbulent flows. To shortcut the prohibitively expansive step of solving the comple...

Key words hydrodynamics – methods: numerical – turbulence We determine the timescales associated with turbulent decay and isotropization in closure models using anisotropically forced and freely decaying turbulence simulations and study the applicability of these models. We compare the results from anisotropically forced three-dimensional numerical simulations with the predictions of the closur...

Reynolds-averaged Navier–Stokes (RANS) methods often cannot predict shock/turbulence interaction correctly. This may be because RANS models do not account for the unsteady motion of the shock wave that is inherent in these interactions. Previous work proposed a shock-unsteadiness correction that significantly improves prediction of turbulent kinetic energy amplification across a normal shock in...

For the past decade, three-dimensional time-dependent computer models have been used to predict and explain how the geomagnetic field is maintained by convection in the Earth’s fluid core. Geodynamo models have simulated magnetic fields that have surface structure and time dependence similar to the Earth’s field, including dipole reversals. However, no dynamo model has yet been run at the spati...