TY - JOUR

T1 - Calculation of Higher-Order Moments in the Atmospheric Boundary Layer

AU - Ilyushin, B. B.

PY - 2018/7/1

Y1 - 2018/7/1

N2 - The results of analyzing a number of models to calculate the statistical fourth-order moments of turbulent fluctuations of vertical velocity and temperature, which describe diffusion processes in equations for triple correlations in RANS models, are presented. Correct calculation of higher-order moments allows adequate description of the impact of large-scale vortex structures on the vertical flow of turbulence energy, as well as the impact of chemical reactions (in the case of reactive impurities) and/or phase transitions (moisture condensation and evaporation) in the atmospheric boundary layer.Results of calculations with the use of the quasi-normality hypothesis, a number of empirical formulas. and algebraic models for fourth-order cumulants are comparedwith in situ measurements in the convective boundary layer of the atmosphere. It is shown that the secondorder- closure models, which are much more efficient in numerical implementation than the thirdorder models, predict the behavior of the higher-order moments not worse than the latter.

AB - The results of analyzing a number of models to calculate the statistical fourth-order moments of turbulent fluctuations of vertical velocity and temperature, which describe diffusion processes in equations for triple correlations in RANS models, are presented. Correct calculation of higher-order moments allows adequate description of the impact of large-scale vortex structures on the vertical flow of turbulence energy, as well as the impact of chemical reactions (in the case of reactive impurities) and/or phase transitions (moisture condensation and evaporation) in the atmospheric boundary layer.Results of calculations with the use of the quasi-normality hypothesis, a number of empirical formulas. and algebraic models for fourth-order cumulants are comparedwith in situ measurements in the convective boundary layer of the atmosphere. It is shown that the secondorder- closure models, which are much more efficient in numerical implementation than the thirdorder models, predict the behavior of the higher-order moments not worse than the latter.

UR - http://www.scopus.com/inward/record.url?scp=85051228803&partnerID=8YFLogxK

U2 - 10.1134/S1810232818030098

DO - 10.1134/S1810232818030098

M3 - Article

AN - SCOPUS:85051228803

VL - 27

SP - 339

EP - 344

JO - Journal of Engineering Thermophysics

JF - Journal of Engineering Thermophysics

SN - 1810-2328

IS - 3

ER -