Low turbulence natural convection in an air filled square cavity

High Rayleigh number convection in a cubic cell with adiabatic sidewalls

“…Experimental realization of 2D turbulent convective flows is a complicated task because 2-D flow could be unstable to 3-D perturbations [4]. Experimental studies of convective flows in a 750 Â 750 Â 1500 mm 3 rectangular tank at Ra ¼ 1:58 Á 10 9 were proposed as experimental benchmark for 2D convection in a square cavity with isothermal vertical borders [5,6]. Approximately two-dimensional air flows were realized in tall rectangular cavities with a small aspect ratio C ¼ 0:013 [7] and C ¼ 0:03 [8,9] (the aspect ratio C is defined as the ratio of the smaller horizontal dimension to the height).…”

Numerical Study of Natural Convection in an Enclosure with an Internal Heat Source at Higher Rayleigh Numbers

“…This shows that the laminar equations with refined time steps can predict the flow behavior with accuracies comparable to that of the turbulent models at high Ra. The simulations for the current study at high Ra (10 10 , 10 11 ) have also been done by solving laminar equations with refined time steps (as solved by Ravi and colleagues [6] in their work at high Ra).…”

“…It was found that the system transits from a fixed point towards chaos via a limit cycle, a period-doubling cascade, periodic windows, and tangential bifurcations with increase in Ra. Tian and Karayiannis [11] studied experimentally low level turbulence natural convection in a 3D cavity having 2D flow for Ra = 1.58 × 10 9 . They reported that low level turbulence existed in the cavity.…”

“…They presented wall shear stress and Nu which can be used for CFD code validation. Tian and Karayiannis [12] in their subsequent paper characterized the turbulence in the cavity presenting RMS of fluctuating temperature, velocities and Reynolds stresses. They found that turbulence region had a base frequency of 0.1 to 0.2 Hz and fluctuations in temperature and velocity were separate.…”

Multiple semi-coarsened multigrid method with application to large eddy simulation

“…Boundary conditions were u = v = w = 0 for all walls (x = 0; L, y = 0; L). The temperature T = T h = 1 was applied to the hot wall at x = 0, and T = T c = 0 to the cold wall at x = L. Along the horizontal side walls, a Dirichlet boundary condition was applied to match the measured proÿles reported in the recent experimental work of Tian and Karianis [24,25]. A periodic boundary condition was applied in the z-direction.…”