TY - JOUR T1 - Temporal Evolution and Scaling of Mixing in Turbulent Thermal Convection for Inhomogeneous Boundary Conditions AU - Wei , Yikun AU - Dou , Hua-Shu AU - Zhu , Zuchao AU - Wang , Zhengdao AU - Qian , Yuehong AU - Xue , Haihong JO - Advances in Applied Mathematics and Mechanics VL - 5 SP - 1035 EP - 1051 PY - 2018 DA - 2018/05 SN - 9 DO - http://doi.org/10.4208/aamm.2016.m1562 UR - https://global-sci.org/intro/article_detail/aamm/12188.html KW - Thermal convection, Turbulence, inhomogeneous boundary conditions, Lattice Boltzmann method. AB -

Numerical simulations of two-dimensional (2D) turbulent thermal convection for inhomogeneous boundary condition are investigated using the lattice Boltzmann method (LBM). This study mainly appraises the temporal evolution and the scaling behavior of global quantities and of small-scale turbulence properties. The research results show that the flow is dominated by large-scale structures in the turbulence regime. Mushroom plumes emerge at both ends of each heat source, and smaller plumes increasingly rise. It is found that the gradient of root mean-square (rms) vertical velocities and the gradient of the rms temperature in the bottom boundary layer decrease with time evolution. It is further observed that the temporal evolution of the Kolmogorov scale, the kinetic-energy dissipation rates and thermal dissipation rates agree well with the theoretical predictions. It is also observed that there is a range of linear scaling in the 2nd-order structure functions of the velocity and temperature fluctuations and mixed velocity-temperature structure function.