Direct numerical simulation of a turbulent channel flow where all essential scales of motion are resolved.
Re = 3300 based on channel half height and centreline velocity.
A diagram of the flow geometry and co-ordinate system are shown below in figure 1. The channel half-width is designated .
The initial choice of the computational domain is made by examining experimental two-point correlations. The computational domain is adjusted as necessary to ensure that the turbulent fluctuations are uncorrelated at a separation of one half-period in the homogenous directions.
The computation is carried out with 3,962,880 grid points (192 × 129 × 160, in x, y, z). For the Reynolds number considered here, the streamwise and spanwise computational periods are chosen to be 4 and 2, respectively (2300 and 1150 in wall units). With this computational domain, the grid spacings in the streamwise and spanwise directions are respectively x+ 12 and z+ 7 in wall units. Non uniform meshes are used in the normal direction with yj = cos j for j = (j-1)/(N-1), j = 1, 2,...., N. Here N is the number of grid points in the y direction. The first mesh point away from the wall is at y+ 0.05 and the maximum spacing (at the centreline of the channel) is 4.4 wall units. No subgrid-scale model is used in the computation.
Fully developed channel flow.
Computations carried out for a Reynolds number of 3300, which is based on the mean centreline velocity Uc and the channel half-width (a Reynolds number of 180 based on the wall shear velocity ).
Previous and Reference Numerical Solutions
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