!------------------------------------------------------------------------------- !VERS ! This file is part of Code_Saturne, a general-purpose CFD tool. ! ! Copyright (C) 1998-2011 EDF S.A. ! ! This program is free software; you can redistribute it and/or modify it under ! the terms of the GNU General Public License as published by the Free Software ! Foundation; either version 2 of the License, or (at your option) any later ! version. ! ! This program is distributed in the hope that it will be useful, but WITHOUT ! ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS ! FOR A PARTICULAR PURPOSE. See the GNU General Public License for more ! details. ! ! You should have received a copy of the GNU General Public License along with ! this program; if not, write to the Free Software Foundation, Inc., 51 Franklin ! Street, Fifth Floor, Boston, MA 02110-1301, USA. !------------------------------------------------------------------------------- ! Purpose : ! --------- ! User subroutine dedicated to Fluid - Structure internal coupling ! --- Definition and management of internal Fluid Structure coupled calculations, ! using a simplified solid modeling (linear "mass, friction and spring" modeling). ! Here are 2 differents subroutines that need to be filled : ! - USSTR1 : Called at the beginning of the calculation. It enables one to define ! internal structures and corresponding initial conditions (initial ! displacement and velocity). ! - USSTR2 : Called at each time step of the calculation. Here one defines ! structural parameters (considered to be potentially time dependent), ! i.e. Mass, Friction, Stiffness and Fluid Stresses. ! --- Boundary faces identification ! ============================= ! Boundary faces may be identified using the 'getfbr' subroutine. ! The syntax of this subroutine is described in the 'usclim' subroutine, ! but a more thorough description can be found in the user guide. !------------------------------------------------------------------------------- subroutine usstr1 & !================ ( idfstr , & aexxst , bexxst , cfopre , & xstr0 , vstr0 , xstreq ) !=============================================================================== ! Purpose : ! --------- ! --- Definition of internal structures and corresponding initial conditions ! (initial displacement and velocity ) !------------------------------------------------------------------------------- ! Arguments !__________________.____._____.________________________________________________. ! name !type!mode ! role ! !__________________!____!_____!________________________________________________! ! idfstr(nfabor) ! ia ! <-- ! boundary faces -> structure definition ! ! aexxst,bexxst ! r ! <-- ! prediction coefficients of structural data ! ! cfopre ! r ! <-- ! prediction coefficients of fluid forces ! ! xstr0(ndim, ! ra ! <-- ! initial displacement of internal structures ! ! nbstru) ! ! ! ! ! vstr0(ndim, ! ra ! <-- ! initial velocity of internal structures ! ! nbstru) ! ! ! ! ! xstreq(ndim, ! ra ! <-- ! displacement of initial mesh compared to ! ! nbstru) ! ! ! the structures position at equilibrium ! !__________________!____!_____!________________________________________________! ! Type: i (integer), r (real), s (string), a (array), l (logical), ! and composite types (ex: ra real array) ! mode: <-- input, --> output, <-> modifies data, --- work array !=============================================================================== !=============================================================================== ! Module files !=============================================================================== use paramx use cstnum use optcal use entsor use albase use parall use period use mesh !=============================================================================== implicit none ! Arguments integer nbstru integer idfstr(nfabor) double precision aexxst, bexxst, cfopre double precision xstr0(3,nstrmx), xstreq(3,nstrmx) double precision vstr0(3,nstrmx) ! Local variables integer ifac integer ilelt, nlelt integer, allocatable, dimension(:) :: lstelt !=============================================================================== ! TEST_TO_REMOVE_FOR_USE_OF_SUBROUTINE_START !if(1.eq.1) then ! nbstru = 0 ! return !endif ! TEST_TO_REMOVE_FOR_USE_OF_SUBROUTINE_END !=============================================================================== ! 1. Initialization !=============================================================================== ! Allocate a temporary array for boundary faces selection allocate(lstelt(nfabor)) !=============================================================================== ! 2. Definition of internal structures !=============================================================================== ! Here one fills array IDFSTR(NFABOR) ! For each boundary face IFAC, IDFSTR(IFAC) is the number of the structure ! the face belongs to (if IDFSTR(IFAC) = 0, the face IFAC doesn't ! belong to any structure.) ! When using internal coupling, structure number necessarily ! needs to be positive (as shown in following examples). ! The number of "internal" structures is automatically defined with the ! maximum value of IDFSTR table, meaning that ! internal structure numbers must be defined sequentially with positive values, ! beginning with integer value '1'. ! In following example, boundary faces with color 4 belong to internal structure '1'. ! Boundary faces with color 2 belong to internal structure '2'. ! The total number of internal structures equals 2. ! Boundary faces identification ! ============================= ! Boundary faces may be identified using the 'getfbr' subroutine. ! The syntax of this subroutine is described in the 'usclim' subroutine, ! but a more thorough description can be found in the user guide. !CALL GETFBR('4',NLELT,LSTELT) !========== !do ilelt = 1, nlelt ! ifac = lstelt(ilelt) ! idfstr(ifac) = 1 !enddo CALL GETFBR('paroi',NLELT,LSTELT) !========== do ilelt = 1, nlelt ifac = lstelt(ilelt) idfstr(ifac) = 1 enddo ! --- For each internal structure one can here define : ! - an initial velocity VSTR0 ! - an initial displacement XSTR0 (i.e. XSTR0 is the value of the displacement XSTR ! compared to the initial mesh at time t = 0) ! - a displacement compared to equilibrium XSTREQ (i.e. XSTREQ is the initial displacement ! of the internal structure compared to its position at equilibrium; at each ! time step t and for a displacement XSTR(t) associated internal structure will be ! subjected to a force -k*(XSTR(t)+XSTREQ) due to the spring). ! --- Note that XSTR0, XSTREQ and VSTR0 arrays are initialized at the beginning of the calculations ! to the value of 0. ! --- When starting a calculation using ALE, or re-starting a calculation with ALE basing ! on a first calculation without ALE, an initial iteration 0 is automatically calculated ! in order to take initial arrays XSTR0, VSTR0 and XSTREQ into account. In another case ! add the following expression 'italin=1' in subroutine 'usalin', so that the code can ! deal with arrays XSTR0, VSTR0 or XSTREQ. ! --- In the following example : ! - internal structure '1' has got an initial displacement XSTR0 = 2 (m) in 'y' direction and ! a displacement compared to equilibrium XSTREQ = 1 (m) in 'y' direction, too. ! - Initial velocity in 'z' direction of structure '2' equals VSTR0=-0.5 (m/s). xstr0(1,1) = 0.d0 xstr0(2,1) = 0.d0 xstr0(3,1) = 0.d0 xstreq(1,1) = 0.d0 xstreq(2,1) = 0.d0 xstreq(3,1) = 0.d0 vstr0(1,1) =0.d0 vstr0(2,1) =0.d0 vstr0(3,1) =0.d0 ! --- Here one can modify the values of the prediction coefficients for ! displacements anf fluid forces in internal FSI coupled algorithm. ! ! the use of these coefficients is reminded here : ! - predicted displacement = X(n) + aexxst * DT * X'(n) ! + bexxst * DT * (X'(n)-X'(n-1)) ! X(n) stands for the displacement at iteration 'n' ! X'(n) and X'(n-1) represent internal structure velocity respectively ! at iteration 'n' and 'n-1'. ! - fluid force sent to structure internal solver = CFOPRE * F(n) ! + (1.D0-CFOPRE) * F(n-1) ! F(n) and F(n-1) stand for fluid force acting on the structure respectively ! at iteration 'n' and 'n-1'. aexxst = 0.5d0 bexxst = 0.0d0 cfopre = 2.d0 ! --- Activation of structural history output (i.e. displacement, structural velocity, ! structural acceleration anf fluid force) ! (ihistr=0, not activated ; ihistr=1, activated) ! The value of structural history output step is the same as the one for standard ! variables ('NTHIST'). ihistr = 1 ! Deallocate the temporary array deallocate(lstelt) return end subroutine !=============================================================================== subroutine usstr2 & !================ ( nbstru , & idfstr , & dtcel , & xmstru , xcstru , xkstru , xstreq , xstr , vstr , forstr , & dtstr ) !=============================================================================== ! Purpose : ! --------- ! --- Definition of structural parameters in case of Fluid Structure internal coupling : ! Mass, Friction, Stiffness anf Fluid Stresses. ! !------------------------------------------------------------------------------- ! Arguments !__________________.____._____.________________________________________________. ! name !type!mode ! role ! !__________________!____!_____!________________________________________________! ! nbstru ! e ! <-- ! nombre de structures definies ! ! nvar ! i ! <-- ! total number of variables ! ! nscal ! i ! <-- ! total number of scalars ! ! idfstr(nfabor ! te ! <-- ! definition des structures ! ! dtcel(ncelet) ! ra ! <-- ! time step (per cell) ! ! xmstru(ndim, ! ra ! --> ! matrix of structural mass ! ! ndim,nbstru) ! ! ! ! ! xcstru(ndim, ! ra ! --> ! matrix of structural friction ! ! ndim,nbstru) ! ! ! ! ! xkstru(ndim, ! ra ! --> ! matrix of structural stiffness ! ! ndim,nbstru) ! ! ! ! ! xstreq(ndim, ! ra ! <-- ! displacement of initial mesh compared to ! ! nbstru) ! ! ! the structures position at equilibrium ! ! xstr(ndim, ! ra ! <-- ! structural displacement ! ! nbstru) ! ! ! ! ! vstr(ndim, ! ra ! <-- ! structural velocity ! ! nbstru) ! ! ! ! ! forstr(ndim ! ra ! <-- ! forces acting on structures (take forces ! ! nbstru) ! ! ! due to fluid effects into account ) ! ! dtstr(nbstru) ! ra ! --> ! structural time step ! !__________________!____!_____!________________________________________________! ! Type: i (integer), r (real), s (string), a (array), l (logical), ! and composite types (ex: ra real array) ! mode: <-- input, --> output, <-> modifies data, --- work array !=============================================================================== !=============================================================================== ! Module files !=============================================================================== use paramx use cstnum use optcal use albase use parall use period use mesh !=============================================================================== implicit none ! Arguments integer nbstru integer idfstr(nfabor) double precision dtcel(ncelet) double precision xmstru(3,3,nstrmx) double precision xcstru(3,3,nstrmx) double precision xkstru(3,3,nstrmx) double precision xstreq(3,nstrmx) double precision xstr(3,nstrmx) double precision vstr(3,nstrmx) double precision forstr(3,nstrmx) double precision dtstr(nstrmx) ! VARIABLES LOCALES integer ii, jj, istr double precision theta, sint, cost, xm, xc, xk, fx, fy !=============================================================================== ! TEST_TO_REMOVE_FOR_USE_OF_SUBROUTINE_START !if(1.eq.1) return ! TEST_TO_REMOVE_FOR_USE_OF_SUBROUTINE_END !=============================================================================== ! 1. INITIALIZATION !=============================================================================== !=============================================================================== ! 2. Structural parameters (subroutine usstr2 is called at each time step ! of the calculation) !=============================================================================== ! --- For each internal structure one defines here : ! - its Mass (XMSTRU) ! - its Friction coefficient C (XCSTRU) ! - its Stiffness K (XKSTRU) ! FORSTR array gives fluid stresses acting on each internal structure. Moreover ! it's possible to take external forces (gravity for example )into account, too. ! XSTR array indicates the displacement of the structure compared to its position ! in initial mesh. ! XSTR0 array gives the displacement of the structures in initial mesh compared to ! structural equilibrium. ! VSTR array stands for structural velocity. ! XSTR, XSTR0, and VSTR arrays are DATA tables that can be used to define arrays ! Mass, Friction and Stiffness. THOSE ARE NOT TO BE MODIFIED. ! The 3D structural equation that is solved is the following one : ! M.X'' + C.X' + K.(X+X0) = F (1) ! = - = - = - -- - ! X stands for the structural displacement compared to initil mesh postition (XSTR) ! - ! X0 represents the displacement of the structure in initial mesh compared to equilibrium ! -- ! Note that M, C and K are 3x3 matrices. ! = = = ! Equation (1) is solved using a Newmark HHT algorithm. ! Note that the time step used to solve this equation (DTSTR) can be different from the one of fluid ! calculations. USER is free to define DTSTR array. At the beginning of the calculation DTSTR is ! initialized to the value of DTCEL (Fluid time step). ! ! --- Matrices XMSTRU, XCSTRU and XKSTRU are initialized to the value of 0. !do istr = 1, nbstru ! do ii = 1, 3 ! do jj = 1, 3 ! xmstru(ii,jj,istr) = 0.d0 ! xcstru(ii,jj,istr) = 0.d0 ! xkstru(ii,jj,istr) = 0.d0 ! enddo ! enddo !enddo ! --- Example 1): In following example structure '1' is defined as an isotropic system (i.e. matrices ! M, C and K are diagonal) : mass equals 5 kg, stiffness equals 2 N/m and friction ! = = = ! coefficient equals 3 kg.s . do ii = 1, 3 xmstru(ii,ii,1) = 5.d0 xcstru(ii,ii,1) = 3.d0 xkstru(ii,ii,1) = 2.d0 enddo ! --- Example 2): In this example structure '2' is subjected to the following movement : ! - In plane xOy the movement is locally defined along an axis (OX). Structural parameters ! in X direction are called xm, xc and xk. The angle of inclination between global (Ox) axis ! and local (OX) axis is called THETA. Movement in local (OY) direction is imposed to be rigid. ! - In 'z' direction the movement is modeled to be oscillating and harmonic (meaning that ! there is no friction). Mass equals 1. kg and stiffness equals 1. N/m. Fluid stresses in that direction ! are taken into account. Moreover the structure is also subjected to an external oscillating ! force Fz_ext = 3 * cos(4*t). ! This leads to the following local equations : ! xm.X'' + xc.X' + xk.X = FX ! Y = 0 ! Z'' + Z = FZ + 3.cos(4.t) theta = pi/6.d0 cost = cos(theta) sint = sin(theta) ! FX, FY, and FZ stand for the local fluid forces components. They are defined as follows, using gobal ! components of fluid forces Fx, Fy and Fz . ! FX = COST*Fx + SINT*Fy ! FY = -SINT*Fx + COST*Fy ! FZ = Fz ! After changing of basis, the problem can be described as follows, using global coordinates: xm = 1.d0 xc = 3.d-1 xk = 2.d0 fx = forstr(1,1) fy = forstr(2,1) forstr(1,1) = fx*cost**2 + fy*sint*cost forstr(2,1) = fx*sint*cost + fy*sint**2 forstr(3,1) = forstr(3,1) + 3.d0*cos(4.d0*ttcabs) do istr = 1, nbstru dtstr(istr) = dtcel(1) enddo return end subroutine