Vorticity Equations During a turbulent motion
and
become random
functions of space and time, and they may be decomposed into a mean and fluctuating
parts. i.e.,
where and
are the mean
quantities and
and are
the fluctuating parts. As was noted before, a bar on the top of the letter
stands for the (time) averaged quantity.
Substituting (11) and (12) into Equation (10) after
averaging we find the mean vorticity transport equation. That is
.
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(13)
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Subtracting (13) from (10) leads to the equation for the vorticity fluctuation
field. That is
.
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(14)
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Equation (14) may be used to derive the mean square vorticity or dissipation
rate transport equations.
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