Sensitivity analysis of initial condition parameters on the transitional temporal turbulent mixing layer

Abstract

This paper aims at determining the most influential inlet turbulence parameters on the downstream transitional mixing region. To this end, a stochastic method is developed to generate a divergence-free random velocity field with a prescribed energy distribution in physical and wave-number space. In addition, predetermined integral length scales can be established. Ten direct numerical simulations of a temporally evolving transitional turbulent mixing layer are examined in detail. Simulation results show a large disparity in mean and instantaneous turbulent quantities, mainly effected by the energy spectrum, the integral length scale and the divergence freeness of the initial field.

Keywords:

• direct numerical simulation
• stochastic turbulence
• divergence-free operator
• temporal mixing layer
• initial condition

PACS:

• 47.27.Eq
• 47.27.Cn

Acknowledgements

This research was performed in the framework of FWO-project G.0130.02. The authors are grateful for the financial support by FWO-Vlaanderen.