Rayleigh-Benard on a logarithmic lattice
By Keaton Burns
Our ability to numerically study turbulent convection is limited by the high cost of direct numerical simulations (DNS) in the regimes relevant to geophysical and astrophysical flows. This motivates the development of alternatives to DNS which enable faster computation by using reduced models of the full dynamics. Here we explore the use of logarithmic Fourier lattices (LFLs) combined with sparse Chebyshev methods to capture extreme dynamic ranges of spatial scales in Rayleigh-Benard and rotating convection. LFL schemes use a Fourier series with logarithmically rather than linearly distributed wavenumbers. We will discuss ongoing work testing different forms of LFL discretizations by examining their ability to reproduce spectra and transport scalings at extreme parameters. This includes formulations with different lattice spacings, triad weightings, and new modifications for the inclusion of coherent structures.
Co-authors: Steven Tobias (Univ. Edinburgh), Curtis Saxton (Univ. Leeds), Richard Kerswell (Univ. Cambridge)