Turbulence structure over heated surfaces: Numerical solutions

Abstract

The structure of air turbulent motions inside closed volumes (without exchange of material through the boundary) over inhomogeneously heated underlying surfaces is studied by the numerical solution of boundary problems for hydrodynamics equations (Navier–Stokes). Large solitary vortices (coherent structures, topological solitons) are observed over inhomogeneously heated surfaces. The number of vortices and their internal structure depend on the form and size of heated inhomogenities. In the case of simple forms of heating (homogeneous heating, a round heated spot), a coherent turbulence induced by the decay of coherent vortices is observed inside a closed volume. For complex forms of heating (thermal diversity), the toroidal vortices are noticeably deformed. The vortices can be extended along the surface and have spiral (helix) streamlines. The vortices are noticeably mixed during the evolution, which results in a Kolmogorov (incoherent) turbulence. Experimental data received earlier inside dome rooms of astronomical telescopes confirm our numerical simulation.