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A numerical study of heat island flows: Stationary solutions
Author(s) -
Dubois Thierry,
Touzani Rachid
Publication year - 2008
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.1840
Subject(s) - discretization , finite volume method , stratification (seeds) , natural convection , mechanics , thermal , boussinesq approximation (buoyancy) , geometry , grid , convergence (economics) , convection , mathematics , geology , meteorology , mathematical analysis , physics , rayleigh number , seed dormancy , germination , botany , dormancy , economics , biology , economic growth
We present two‐dimensional numerical simulations of a natural convection problem in an unbounded domain. The flow circulation is induced by a heat island located on the ground and thermal stratification is applied in the vertical direction. The main effect of this stably stratified environment is to induce the propagation of thermal perturbations in the horizontal direction far from the local thermal source. Numerical stationary solutions at Ra ⩽10 5 are computed in large elongated computational domains: convergence with respect to the domain sizes is investigated at different resolutions. On fine grids, with mesh size ${h} = {{1} \over {128}}$ , a thermal sponge layer is added at the vertical boundaries: this local damping technique improves the convergence with respect to the domain length. Boussinesq equations are discretized with a second‐order finite volume scheme on a staggered grid combined with a second‐order projection method for the time integration. Copyright © 2008 John Wiley & Sons, Ltd.