Finite element simulation of buoyancy-driven turbulent flows [Elektronische Ressource] / vorgelegt von Tobias Knopp

Finite-element simulationofbuoyancy-driven turbulent owsDissertationzur Erlangung des Doktorgradesder Mathematisch-Naturwissenschaftlichen Fakult atender Georg-August-Universit at zu G ottingenvorgelegt vonTobias KnoppausLub eckG ottingen 2003D7Referent: Prof. Dr. G. LubeKorreferent: Prof. Dr. R. SchabackTag der mundlic hen Prufung: 4. Juni 20032ContentsPreface 7Epitome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9I. Turbulence modelling for buoyancy driven ows 111. The laminar model 131.1. Laminar thermally coupled ow problems . . . . . . . . . . . . . . . . . . . 131.2. Boundary conditions for thermally coupled ows . . . . . . . . . . . . . . . 151.3. A model for non-isothermal ow problems . . . . . . . . . . . . . . . . . . . 181.4. Modelling turbulent boundary layers using a fully overlapping DDM . . . . 192. Fundamentals, modelling and simulation of turbulent ows 232.1. Aspects of randomness and statistical description of turbulent ows . . . . 232.2. The scales of turbulent ows . . . . . . . . . . . . . . . . . . . . . . . . . . 262.3. Criteria for appraising approaches in CFD . . . . . . . . . . . . . . . . . . . 273. The k= turbulence model 293.1. The Reynolds averaged Navier-Stokes equations . . . . . . . . . . . . . . . . 293.2. Turbulent-viscosity and gradient-di usion hypotheses . . . . . . . . . . . . .