Multi-scale Analysis of Turbulence in CFD-Simulations

We performed a 3D DNS simulation using spectral/hp method on an fx79-w151a airfoil at a Reynolds number of Re=5000 at an angle of attack of alpha = 12 degrees. Due to a separating flow, an inhomogeneous turbulent field evolved in the wake above the trailing edge. Within this field time series of the flow properties have been gathered at selected points. The data of the time series at one point have been analyzed on the back ground of a multipoint correlation method. From statistics of velocity increments Kramers-Moyal coefficients have been estimated. The resulting stochastic process given by the Kramers-Moyal coefficients have been used to reconstruct a time series of the flow velocity increments at a differing point in space within the flow field. Even though the short dataset enabled just a first impression of the method, the results showed a surprisingly good agreement.