The case considered is natural convection flow between two differentially heated, infinite vertical walls. DNS data is available for a range of Rayleigh numbers from 105 to 5x106.
The cavity is of width 2h, as shown in the figure, and the temperature
difference between the two walls is defined as 
T=Thot-Tcold. The
non-dimensional parameter characterising the flow is the Rayleigh number Ra =g
T(2h)3/(
k) where g is acceleration due to gravity, the coefficient of volumetric
expansion, the kinematic
viscosity and k the heat conduction coefficent.
DNS data is available from 2 independent simulations. The first, by Boudjemadi et al (1996) employed a mixed spectral/finite difference approach to simulate the flow at Rayleigh numbers of 105 and 5.4x105 on a 128 x 32 x 128 grid covering a domain of size 5h, 2h and 2h in the vertical, spanwise and wall-normal directions respectively.
The simulations were run with a distance h=0.5 and temperature difference T=1. The results are
normalized using the friction velocity u* and temperature 
*=k/u*(dT/dy)]wall.
In the simulations it was found that *=0.0515T
and 0.0582T for the low
and high Rayleigh numbers respectively. Similarly, the friction velocity was found to be u*/Vb=4.94x10-4
and 1.637x10-4 for the two cases respectively, where the reference velocity Vb=gT(2h)2/.
The second set of simulations, by Nieuwstadt and Versteegh (1997) studied the flow at Rayleigh numbers of 5.4x105, 8.2x105, 2x106 and 5x106. In this case, a finite volume scheme was used on a 432 x 216 x 96 grid covering a domain of 24h x 12h x 2h in the vertical, spanwise and wall-normal directions respectively.
Both simulations were carried out using a Prandtl number Pr=/k of 0.71.
The flow only requires a 1-dimensional computation to be carried out, with constant temperatures applied at the two walls.
Since we will only be comparing normalized quantities, the dimensions and fluid
property values can be chosen by participants. If the above h and T from the first case are
taken, for example, then suitable values should be assigned to g, and to give the required Rayleigh numbers.
We intend to make comparisons of the profiles of mean velocity and temperature and of the second-moment statistics across the cavity.
Data of Boudjemadi et al:
case5_3edf.tar.gz (for gunzip)
case5_3edf.tar.Z (for uncompress)
Data of Nieuwstadt and Versteegh:
case5_3vn.tar.gz (for gunzip)
case5_3vn.tar.Z (for uncompress)
Boudjemadi, R., Maupu, V., Laurence, D., Le Quere, P. 1997 "Budgets of turbulent stresses and fluxes in a vertical slot natural convection flow at Rayleigh Ra=105 and 5.4x105" Int. J. Heat Fluid Flow, 18, 70-79.
Versteegh, T.A.M., Nieuwstadt, F.T.M. 1997 "Coherent structures in natural convection between two vertical, differentially heated walls" Proc. 2nd Int. Symposium on Turbulence, Heat and Mass Transfer, Delft.
Nieuwstadt, F.T.M., Versteegh, T.A.M. 1997 "DNS of natural convection between two vertical, differentially heated walls" Proc. 11th Turbulent Shear Flows Symposium, Grenoble.