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Calculation of turbulent inlet conditions for a circular duct flow with smooth wall. More...
Functions/Subroutines | |
subroutine | keendb (uref2, dh, xrho, xmu, cmu, xkappa, ustar2, xk, xeps) |
subroutine | keenin (uref2, xintur, dh, cmu, xkappa, xk, xeps) |
Calculation of ![]() ![]() ![]() ![]() ![]() ![]() | |
Calculation of turbulent inlet conditions for a circular duct flow with smooth wall.
Calculation of ,
and
from a diameter
and the reference velocity
for a circular duct flow with smooth wall (use for inlet boundary conditions).
Both and
are returned, so that the user may compute other values of
and
with the
.
We use the laws coming for Idel'Cik, i.e. the head losses coefficient is defined by:
then the relation reads .
depends on the hydraulic Reynolds number
and is given by:
From , we can estimate
and
from the well known formulae of developped turbulence
subroutine keendb | ( | double precision | uref2, |
double precision | dh, | ||
double precision | xrho, | ||
double precision | xmu, | ||
double precision | cmu, | ||
double precision | xkappa, | ||
double precision | ustar2, | ||
double precision | xk, | ||
double precision | xeps | ||
) |
[in] | uref2 | square of the flow speed of reference |
[in] | dh | hydraulic diameter ![]() |
[in] | xrho | mass density ![]() |
[in] | xmu | dynamic viscosity ![]() |
[in] | cmu | constant ![]() |
[in] | xkappa | constant ![]() |
[out] | ustar2 | square of friction speed |
[out] | xk | calculated turbulent intensity ![]() |
[out] | xeps | calculated turbulent dissipation ![]() |
subroutine keenin | ( | double precision | uref2, |
double precision | xintur, | ||
double precision | dh, | ||
double precision | cmu, | ||
double precision | xkappa, | ||
double precision | xk, | ||
double precision | xeps | ||
) |
Calculation of ,
and
from a diameter
, a turbulent intensity
and the reference velocity
for a circular duct flow with smooth wall (use for inlet boundary conditions).
[in] | uref2 | square of the flow velocity of reference |
[in] | xintur | turbulent intensity ![]() |
[in] | dh | hydraulic diameter ![]() |
[in] | cmu | constant ![]() |
[in] | xkappa | constant ![]() |
[out] | xk | calculated turbulent intensity ![]() |
[out] | xeps | calculated turbulent disspation ![]() |