Numerical Simulations of Sheared Conditionally Unstable Flows over a Mountain Ridge

Large numerical simulations of turbulent rotating flows

Scientific context Rotation, as measured by the Rossby number (the ratio of the rotation period to the eddy turn over time) is present in astroand geophysics. For example, the high Reynolds number large scales of atmospheric and oceanic flows are affected by the rotation of the Earth; the Rossby number Ro = U0/[L0Ω] for mid-latitude atmospheric synoptic scales is Ro ≈ 0.1 whereas in the solar c...

Numerical Simulations of Rotating Accretion Flows near a Black Hole

We present time-dependent solutions of thin, supersonic accretion flows near a black hole and compare them with analytical solutions. Such flows of inviscid, adiabatic gas are characterized by the specific angular momentum and the specific energy. We confirm that for a wide range of above parameters a stable standing shock wave with a vortex inside it forms close to the black hole. Apart from s...

Numerical Investigation on Contaminant Dispersion from a Source over the Blocks in Steady and Unsteady Flows

This paper deals with numerical study of semi-finite incompressible flow of air over two blocks with different heights in the presence of a condensing-source, dispensing- contaminant in the flow, in both steady and unsteady states. The numerical solution of governing PDE equations are constructed by a finite-volume method applied on structured grid arrangement. The effects of air flow velocity,...

Noise delayed decay of unstable states: theory versus numerical simulations

We study the noise delayed decay of unstable nonequilibrium states in nonlinear dynamical systems within the framework of the overdamped Brownian motion model. We give the exact expressions for the decay times of unstable states for polynomial potential profiles and obtain nonmonotonic behavior of the decay times as a function of the noise intensity for the unstable nonequilibrium states. The a...

A numerical method for vibro-acoustic problems with sheared mean flows