Time stepper for Nek5000. More...

Collaboration diagram for Time stepper routines:

Modules
	Arnoldi algorithm using parpack
	Arnoldi algorithm with PARPACK.

	Power itertion routines
	Power iteration submodule.

Files
file	tstpr.f
	Set of subroutines to use time steppers for e.g. power iterations or solution of eigenvalue problem with Arnoldi algorithm.

Functions
subroutine	tstpr_register ()
	Register time stepper module. More...

subroutine	tstpr_init ()
	Initilise time stepper module. More...

logical function	tstpr_is_initialised ()
	Check if module was initialised. More...

subroutine	tstpr_main ()
	Control time stepper after every nek5000 step and call suitable stepper_vsolve of required submodule. More...

subroutine	tstpr_dssum
	Average velocity and temperature at element faces. More...

Detailed Description

Time stepper for Nek5000.

This module implements time stepper method for linear solver in Nek5000 using the userchk interface. It allows to perform a number of constant length cycles providing the result vector to the submodule. There are two possible submodules: power iteration and spectra calculation using the Arnoldi algorithm implemented in PARPACK. The initial condition for the next stepping cycle is provided by the submodule. Three stepper modes are supported: direct, adjoint, direct+adjoint.

There are two parameters in TSTRP include file that heve to be adjusted for the given setup. These parameters are tstpr_pr and tstpr_ht defining whetere pressure ro themperature are included in the simlulation vector. These parameters can be equal 0 or 1. The pressure is never included in the vector inner product, however for tstpr_pr=0 it is reset to zero at the beginning of each cycle. On the other hand tstpr_ht should be set to 1 for all simulations including temperature.

Todo:: Finish temperature. Check pressure treatment

Module interface:

Global interface list:

Interface provided:

Global interface dependency:

Interface required:

multiple interfaces from Runtime parameters and Monitoring module modules
cnht_register, cnht_init, cnht_is_initialised, cnht_glsc2_wt, cnht_cpfld_set and cnht_opcmult from Conjugated heat transfer tools module (automatically registered)
stepper_register; provided by a submodule
stepper_init; provided by a submodule
stepper_vsolve; provided by a submodule

Module interface usage:: !======================================================================

subroutine userchk

include 'TSTEP'

if (istep.eq.0) then

! start framework

call frame_start

endif

! monitor simulation

call frame_monitor

! call time stepper

call tstpr_main()

! finalise framework

if (istep.eq.nsteps.or.lastep.eq.1) then

call frame_end

endif

return

end

!======================================================================

subroutine frame_usr_register

implicit none

include 'SIZE'

include 'FRAMELP'

!-----------------------------------------------------------------------

! register modules

call chkpt_register

call tstpr_register()

return

end subroutine

!======================================================================

subroutine frame_usr_init

implicit none

include 'SIZE'

include 'FRAMELP'

!-----------------------------------------------------------------------

! initialise modules

call chkpt_init

call tstpr_init()

return

end subroutine

!======================================================================

subroutine frame_usr_end

implicit none

include 'SIZE'

include 'FRAMELP'

!-----------------------------------------------------------------------

return

end subroutine

!======================================================================

chkpt_init
subroutine chkpt_init()
Initilise checkpointing module.
Definition: chkpt.f:87

chkpt_register
subroutine chkpt_register()
Register checkpointing module.
Definition: chkpt.f:11

frame_monitor
subroutine frame_monitor
Simulataion monitoring.
Definition: frame.f:59

frame_start
subroutine frame_start
Start framework.
Definition: frame.f:12

frame_end
subroutine frame_end
Finalise framework.
Definition: frame.f:76

tstpr_main
subroutine tstpr_main()
Control time stepper after every nek5000 step and call suitable stepper_vsolve of required submodule.
Definition: tstpr.f:259

tstpr_init
subroutine tstpr_init()
Initilise time stepper module.
Definition: tstpr.f:108

tstpr_register
subroutine tstpr_register()
Register time stepper module.
Definition: tstpr.f:12

Module parameters:

Global parameter list:: Parameters provided by time stepper module (include file - TSTPRD):

Varaible	Type	Runtime parameter	Description
tstpr_mode	integer	_tstpr:mode	simulation mode (1-direct, 2-adjoint, 3-direct+adjoint)
tstpr_step	integer	_tstpr:steps	frequency of calling stepper_vsolve (number of time steps)
tstpr_cmax	integer	_tstpr:maxcycles	maximal number of stepper cycles
tstpr_tol	real	_tstpr:tol	convergence tolerance (e.g. PARPACK tolerance for Ritz values)

Module parameters:

Global parameter dependency:

Parameters required by time stepper module:

Nek5000 PARAM array and logical flags:
- PARAM(12) - time step dt
- IFTRAN, IFPERT, IFBASE, IFHEAT, NSTEPS, NPERT

Module parameter usage:: [_TSTPR] # Runtime paramere section for time stepper module

MODE = DIR # Simulation mode

STEPS = 40 # Length of stepper phase

MAXCYC = 10 # Max number of stepper cycles

TOL = 0.10000000E-05 # Convergence threshold