Channel Flow

DNS by Kim et al.


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Description

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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.

Geometry

A diagram of the flow geometry and co-ordinate system are shown below in figure 1. The channel half-width is designated delta.

figure

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 4pidelta and 2pidelta, respectively (2300 and 1150 in wall units). With this computational domain, the grid spacings in the streamwise and spanwise directions are respectively Deltax+ approx 12 and Deltaz+ approx 7 in wall units. Non uniform meshes are used in the normal direction with yj = cos thetaj for thetaj = (j-1)pi/(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+ approx 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.

Flow Conditions/Parameters

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 delta (a Reynolds number of 180 based on the wall shear velocity utau).

Simulation Details

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Available Results

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Previous and Reference Numerical Solutions

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References

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