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Cheap non-Gaussian turbulence: An example of construction of random vector fields using Ambit Stochastics

Emil Hedevang
(Department of Mathematics, Aarhus University)
Torsdag, 12 marts, 2015, at 13:15-14:00, in Koll. D (1531-211)

Turbulence is not Gaussian. In this talk I will discuss the recently developed framework of Ambit Stochastic and show how it can be used to construct non-Gaussian random vector fields that are easy to simulate from, the main application being the velocity vector field in a turbulent flow. First we see how to reproduce the correlation structure, i.e., the spectral tensor in a homogeneous, isotropic, incompressible vector field. Then we see simple ways of introducing inhomogeneity and anisotropy. Important features of turbulence are the non-Gaussian (peaked, heavy-tailed and slightly skewed) distributions of velocity increments and the intermittency of the energy dissipation. Using the generalized hyperbolic distribution we see how to produce non-Gaussian increments, and using stochastic volatility modulation we see how to produce intermittency.

Organiseret af: The T.N. Thiele Centre
Kontaktperson: Søren Asmussen