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Turbulent Channel Flow

Preliminary Check List

Mass Flow Rate

  • Mass flow from <logfile.dat>
    • Is the mass flow rate constant?
    • Is the bulk-mean velocity (U_b) equal to unity? If not, rescale the velocity to make U_b=1.

Time History

  • Skin friction or Re_tau from <tautotal1.dat>
    • Is it in equilibrium?
    • Is it at the target Re_tau value?
  • Velocity and pressure from <freq1.dat>
    • How does the flow look at different y locations?
    • Are they turbulent/laminar?
    • Is it in equilibrium?
  • Time step size from <cfl.dat>
    • Is the time step constant?
    • Is the time step too large/small?

Time mean profile - 1D

  • Time mean velocity profile from <umean-txza.dat>
    • U, u', v', w' - Does it compare well with other DNS data?
  • Reynolds shear stress <shear-txza.dat>
    • Is the total shear stress linear?

Instantaneous Data - 2D

  • Velocity and pressure contours in the xz plane from <up2-xz.plt>
    • Are low speed streaks clearly seen?
    • Is the velocity field periodic in the streamwise direction?
    • Are there any spurious peaks?
    • Is the pressure fluctuations periodic or NOT?
  • Velocity and pressure contours in the xy plane from <up2-xy.plt>
    • Is the high speed fluid in the channel centre region?
    • Is the no-slip boundary condition satisfied near the channel walls?
    • Does the w contours show the characteristic patterns?
  • Velocity and pressure contours in the yz plane from <up2-yz.plt>
    • Does the vector plot show the streamwise vortices?
    • Does the pressure contours show the centre of the streamwise vortices?

Advanced Check List

Vorticity Fluctuations

TKE (Turbulent Kindtic Energy) Budgets

Higher order statistics