Steady straight towing condition
Measurement location x/L = 0.935
At point A, the number of data N = 1,720 (Ntotal =2,250) collected from 30 carriage runs.
N < Ntotal due to the locally insufficient PIV particle density and by rejecting spurious vectors at the data reduction phase.
Mean axial velocity, U | Turbulent kinetic energy, k |
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U, V, W data are apparently stationary, random, and normal.
Mean values, x = 0.534, -0.023, 0.059
Variance values, s2 = 0.0075, 0.0035, 0.0024
Data | Probability density function |
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Time histories of the mean x and variance s2 values as increasing the number of sample N.
For each N, s2 is recalculated with the new x value using the following recursive equation:
x converges fast, typically for N > 100.
s2 first fluctuates large and converges slowly for N > 500.
Mean | Variance |
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E (% UC) = 0.4, 0.3, 0.3 for U, V, W, respectively.
EU (% k) = 8, 4, 3 for uu, vv, ww, respectively.
Mean velocity | Reynolds normal stresses |
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