Monte Carlo Spectral Integration: a Consistent Approximation for Radiative Transfer in Large Eddy Simulations

摘要: Large-eddy simulation (LES) refers to a class of calculations in which the large energy-rich eddies are simulated directly and are insensitive errors modeling sub-grid scale processes. Flows represented by LES often driven by radiative heating therefore require calculation transfer along with fluid-dynamical simulation. Current methods for detailed radiation calculations, even those using simple one-dimensional transfer, far too expensive routine use, while popular shortcuts are either limited applicability or run risk introducing on time space scales that might affect overall simulation. A new approximate method is described relies Monte Carlo sampling spectral integration rate applicable any problem. The error introduced when using this substantial individual samples (single columns at single times) but uncorrelated so does not bias statistics well resolved LES. evaluated through two test problems; these behave as expected. A scaling analysis shows diminish flow features become resolved. Errors approximation increase decreasing spatial spurious energy approximation is less than expected unperturbed flow, i.e. associated cascade from scale, grid scale.