TY - JOUR
T1 - Energy- and flux-budget (EFB) turbulence closure model for stably stratified flows. Part I
T2 - Steady-state, homogeneous regimes
AU - Zilitinkevich, Sergej S.
AU - Elperin, T.
AU - Kleeorin, N.
AU - Rogachevskii, I.
N1 - Funding Information:
Acknowledgements We thank Vittorio Canuto, Igor Esau, Victor L’vov, Thorsten Mauritsen and Gunil-la Svensson for discussions and Igor Esau for his valuable contribution to data analysis and for making Figures 5 and 6. This work has been supported by EU Marie Curie Chair Project MEXC-CT-2003-509742, EU Project FUMAPEX EVK4-CT-2002-00097, ARO Project W911NF-05-1-0055, Carl-Gustaf Rossby International Meteorological Institute in Stockholm, German-Israeli Project Cooperation (DIP) administrated by the Federal Ministry of Education and Research (BMBF), Israel Science Foundation governed by the Israeli Academy of Science, Israeli Universities Budget Planning Committee (VATAT) and Israeli Atomic Energy Commission.
PY - 2007/11/1
Y1 - 2007/11/1
N2 - We propose a new turbulence closure model based on the budget equations for the key second moments: turbulent kinetic and potential energies: TKE and TPE (comprising the turbulent total energy: TTE = TKE + TPE) and vertical turbulent fluxes of momentum and buoyancy (proportional to potential temperature). Besides the concept of TTE, we take into account the non-gradient correction to the traditional buoyancy flux formulation. The proposed model permits the existence of turbulence at any gradient Richardson number, Ri. Instead of the critical value of Richardson number separating-as is usually assumed - the turbulent and the laminar regimes, the suggested model reveals a transitional interval, 0.1 < Ri < 1, which separates two regimes of essentially different nature but both turbulent: strong turbulence at Ri ≪ 1; and weak turbulence, capable of transporting momentum but much less efficient in transporting heat, at Ri > 1. Predictions from this model are consistent with available data from atmospheric and laboratory experiments, direct numerical simulation and large-eddy simulation.
AB - We propose a new turbulence closure model based on the budget equations for the key second moments: turbulent kinetic and potential energies: TKE and TPE (comprising the turbulent total energy: TTE = TKE + TPE) and vertical turbulent fluxes of momentum and buoyancy (proportional to potential temperature). Besides the concept of TTE, we take into account the non-gradient correction to the traditional buoyancy flux formulation. The proposed model permits the existence of turbulence at any gradient Richardson number, Ri. Instead of the critical value of Richardson number separating-as is usually assumed - the turbulent and the laminar regimes, the suggested model reveals a transitional interval, 0.1 < Ri < 1, which separates two regimes of essentially different nature but both turbulent: strong turbulence at Ri ≪ 1; and weak turbulence, capable of transporting momentum but much less efficient in transporting heat, at Ri > 1. Predictions from this model are consistent with available data from atmospheric and laboratory experiments, direct numerical simulation and large-eddy simulation.
KW - Anisotropy
KW - Critical Richardson number
KW - Eddy viscosity
KW - Heat conductivity
KW - Kinetic, potential and total turbulent energies
KW - Stable stratification
KW - Turbulence closure
KW - Turbulent fluxes
KW - Turbulent length scale
UR - http://www.scopus.com/inward/record.url?scp=34848855725&partnerID=8YFLogxK
U2 - 10.1007/s10546-007-9189-2
DO - 10.1007/s10546-007-9189-2
M3 - Article
AN - SCOPUS:34848855725
SN - 0006-8314
VL - 125
SP - 167
EP - 191
JO - Boundary-Layer Meteorology
JF - Boundary-Layer Meteorology
IS - 2
ER -