A statistical model of strains in homogeneous and isotropic turbulence

A statistical model of strains obeying the Kolmogorov laws in homogeneous and isotropic turbulence is proposed. For given dissipation rate, skewness and flatness the model allows to efficiently generate all components of turbulent strains, thereby simulating turbulent velocity field at time scales below 0.2 s and length scales ranging between the Kolmogorov and inertial scales. The verification test showed that the model successfully reproduces PDF of strains reported in literature, PDF of the total dissipation rate, as well as the PDF of single squared velocity derivatives. The log-normal distribution of the dissipation rate is reproduced in case when effects of turbulent intermittency (skewness and flatness of the PDF of strains) were taken into account. The model has been shown efficient for investigation of motion and collisions of inertial spherical and non-spherical atmospheric particles. Computer codes of the model are available on request.