Dust formation in turbulent media

Ch. Helling, M. Lüttke, E. Sedlmayr, R. Klein

Eighth International Conference on Hyperbolic Problems: Theory, Numerics, Applications (Feb. 2000)

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Abstract:

The present study investigates the role of turbulence in generating an inhomogeneous distribution of solid particles in rarefied gases where colliding gas elements produce acoustic waves with associated temperature, pressure and density enhancements. The dominant physical interactions in the reactive, dust-forming gas flow are estimated and detailed multi-dimensional simulations of compressible fluid-dynamics including dust formation kinetics have been carried out exemplary for physical conditions typical for brown dwarf atmospheres. The dust particle density directly maps the gas density distribution. An inhomogeneous distribution of the dust results. Since the dust formation time scales are considerably smaller than the hydrodynamic time scale, the largest particles are formed at sites of the highest density. Resulting expansion waves cause a decrease of temperature which becomes essential in hot environments.