The ABL case user-file

Contains: user specified routines for the ABL case. More...

Functions/Subroutines
subroutine	uservp (ix, iy, iz, ieg)
	Set variable properties, does not call any subroutines / functions. More...
subroutine	userf (ix, iy, iz, eg)
	Compute Coriolis acceleration. More...
subroutine	userq (ix, iy, iz, eg)
subroutine	useric (ix, iy, iz, eg)
	Set up initial conditions. More...
subroutine	userbc (ix, iy, iz, iside, eg)
	Compute the boundary condition. See subdirectory bc/. More...
subroutine	userchk ()
	Compute the turbulent stress tensors and write statistics. More...
subroutine	userqtl
subroutine	usrdat ()
subroutine	usrdat2 ()
subroutine	usrdat3 ()
	Compute inflow / outflow conditions a.k.a. driving force. Ubar=1 Not required when coriolis force is specified in userf. More...

Detailed Description

Contains: user specified routines for the ABL case.

• uservp() : variable properties
• userf() : local acceleration term for fluid
• userq() : local source term for scalars
• userbc() : boundary conditions
• useric() : initial conditions
• userchk() : general purpose routine for checking errors etc.
• userqtl() : thermal divergence for lowMach number flows
• usrdat() : modify element vertices
• usrdat2() : modify mesh coordinates
• usrdat3() : general purpose routine for initialization

Function/Subroutine Documentation

userbc()

subroutine userbc	(	integer	ix,
		integer	iy,
		integer	iz,
		integer	iside,
		integer	eg
	)

Compute the boundary condition. See subdirectory bc/.

Note

it is OK to define both flux and temp here since only one would be used at the same time. See BCNEUSC(), BCDIRSC() and FACEIS()

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userchk()

subroutine userchk

Compute the turbulent stress tensors and write statistics.

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userf()

subroutine userf	(	integer	ix,
		integer	iy,
		integer	iz,
		integer	eg
	)

Compute Coriolis acceleration.

\[ F_x, F_z = - f\hat{e}_y \times \vec{u} \]

See https://lists.mcs.anl.gov/pipermail/nek5000-users/2014-May/002798.html

Note

The Coroiolis acceleration also absorbs the part of the pressure under hydrostatic balance, which in turn drives the flow. When it is turned off, usrdat3() drives the flow.

Parameters

[in]	ix,iy,iz	GLL point index
[in]	eg	global element number

Todo:

Choose correct Ri

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useric()

subroutine useric	(	integer	ix,
		integer	iy,
		integer	iz,
		integer	eg
	)

Set up initial conditions.

Use standard subroutine RANDOM_NUMBER. See https://gcc.gnu.org/onlinedocs/gfortran/RANDOM_005fNUMBER.html

userq()

subroutine userq	(	integer	ix,
		integer	iy,
		integer	iz,
		integer	eg
	)

userqtl()

subroutine userqtl

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uservp()

subroutine uservp	(	integer	ix,
		integer	iy,
		integer	iz,
		integer	ieg
	)

Set variable properties, does not call any subroutines / functions.

Parameters

ix	x-index
iy	y-index
iz	z-index
ieg	element index

Todo:

Implement turbulent Prandtl number parameter

usrdat()

subroutine usrdat

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usrdat2()

subroutine usrdat2

usrdat3()

subroutine usrdat3

Compute inflow / outflow conditions a.k.a. driving force. Ubar=1 Not required when coriolis force is specified in userf.

See also

https://github.com/Nek5000/NekExamples/blob/70a5792b04b7a4c2da16463f517863b10627398f/turbChannel/turbChannel.usr#L375-L386