Numerical simulation of the evening transition in the atmospheric boundary layer using LES and RANS models
- 1Lomonosov Moscow State University, Moscow, Russian Federation
- 2Moscow Center for Fundamental and Applied Mathematics, Moscow, Russian Federation
- 3A.M. Obukhov Institute of Atmospheric Physics RAS, Moscow, Russian Federation
- 4Marchuk Institute of Numerical Mathematics RAS, Moscow, Russian Federation
Two types of ABL numerical modeling are compared: three-dimensional large-eddy simulation (LES) models and one-dimensional Reynolds-averaged Navier-Stokes (RANS) models. The evening transition is simulated through facilitating the formation of the convective boundary layer (CBL) by having a constant positive surface heat flux, and the subsequent decay of the CBL when the surface heat flux is decreased.
Several features of this process have been studied in relative depth, in particular the TKE decay rate at different stages of the evening transition, the sensitivity of the results to the domain size, and the dynamics of the large- and small-scale turbulence during the transition period. LES experiments with different setups were performed, and the results were then compared to those obtained through RANS experiments based on the k-epsilon model (a two-equation model for TKE and dissipation rate, where model constants are chosen to allow for correct simulation of SBL main properties [1], as well as CBL growth rate [2]).
This study was funded by Russian Foundation of Basic Research within the project N 20-05-00776 and the grant of the RF President within the MK-1867.2020.5 project.
2. Burchard H. Applied Turbulence Modelling in Marine Waters. Berlin, Germany: Springer, 2002. P. 57-59
How to cite: Tkachenko, E., Debolskiy, A., and Mortikov, E.: Numerical simulation of the evening transition in the atmospheric boundary layer using LES and RANS models, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14787, https://doi.org/10.5194/egusphere-egu21-14787, 2021.