tut3d_10

TUTORIAL 10: simple rolling process

Goals of this Unit:

several materials and chambers in 3D
smoothing length definition for chambers, respectively
tear-off criterion

The Fluid Mechanical Problem A fluid coming out of a feeder is rolled into a film by two rolls. The rolls are filled with high-viscosity fluids, such that they practically perform a rigid rotation. The rolls are cooled at the inside. Here should be a picture

Figure 25: (a) Initial Stage of the Point Cloud; (b) Stage when Jet has been cut

Setting up the problem Altogether we have three different materials. In order to handle the model with FPM we introduce three chambers, one for each material:

KOP(1) = LIQUID V:IMPLICIT T:EXPIMP(1.0) LAGRANGE vp- KOP(2) = LIQUID V:IMPLICIT T:EXPIMP(1.0) LAGRANGE vp- KOP(3) = LIQUID V:IMPLICIT T:EXPIMP(1.0) LAGRANGE vp-

For each chamber we need to define a smoothing length, so we define three additional points in the Boundary Elements section:

BND_point &Point_H_Curve1& 0.0 0.0 0.0 BND_point &Point_P_100& 0.0 0.0 0.0 BND_point &Point_P_200& 0.0 0.0 0.0

The rolls do not require a dense particle cloud. In contrast we should use a small smoothing length close to where the two rolls almost touch:

USER_h_funct = 'DSCR' SMOOTH_LENGTH($H_CURVE1$) = ( %H_constant%, 0.4 ) SMOOTH_LENGTH($P_100$) = ( %H_constant%, 0.3 ) SMOOTH_LENGTH($P_200$) = ( %H_constant%, 0.3 )

In the alias section we now have to specify the chamber to which the geometric entities belong. For chamber 1 (the liquid melt), we define

"in" = " REV_ORIENT BC$BC_inflow$ ACTIVE$noinit_always$ IDENT%IDENT_inflow% MAT$GLASS$ TOUCH%TOUCH_always% MOVE$NO_MOVE$ CHAMBER1 " "out_left" = " BC$BC_outflow$ ACTIVE$noinit_always$ IDENT%IDENT_outflow% MAT$GLASS$ TOUCH%TOUCH_liquid% MOVE$NO_MOVE$ CHAMBER1 " "out_right" = " REV_ORIENT BC$BC_outflow$ ACTIVE$noinit_always$ IDENT%IDENT_outflow% MAT$GLASS$ TOUCH%TOUCH_liquid% MOVE$NO_MOVE$ CHAMBER1 " "out_back" = " BC$BC_outflow$ ACTIVE$noinit_always$ IDENT%IDENT_outflow% MAT$GLASS$ TOUCH%TOUCH_liquid% MOVE$NO_MOVE$ CHAMBER1 " "out_front" = " REV_ORIENT BC$BC_outflow$ ACTIVE$noinit_always$ IDENT%IDENT_outflow% MAT$GLASS$ TOUCH%TOUCH_liquid% MOVE$NO_MOVE$ CHAMBER1 " "out_bottom" = " BC$BC_outflow$ ACTIVE$noinit_always$ IDENT%IDENT_outflow% MAT$GLASS$ TOUCH%TOUCH_liquid% MOVE$NO_MOVE$ CHAMBER1 " "roll_left_out" = " REV_ORIENT BC$BC_left_out2$ ACTIVE$noinit_always$ IDENT%IDENT_wall% MAT$GLASS$ TOUCH%TOUCH_liquid% MOVE$MOVE_RLEFT$ CHAMBER1 " "roll_right_out" = " REV_ORIENT BC$BC_right_out2$ ACTIVE$noinit_always$ IDENT%IDENT_wall% MAT$GLASS$ TOUCH%TOUCH_liquid% MOVE$MOVE_RRIGHT$ CHAMBER1 "

For the two other chambers (rolls), we define

"roll_left_front" = " BC$BC_roll_side$ ACTIVE$init_always$ IDENT%IDENT_slip% MAT$MAT_RLEFT$ TOUCH%TOUCH_always% MOVE$MOVE_RLEFT$ CHAMBER2 " "roll_left_back" = " BC$BC_roll_side$ ACTIVE$init_always$ IDENT%IDENT_slip% MAT$MAT_RLEFT$ TOUCH%TOUCH_always% MOVE$MOVE_RLEFT$ CHAMBER2 " "roll_left_in" = " BC$BC_roll_in$ ACTIVE$init_always$ IDENT%IDENT_wall% MAT$MAT_RLEFT$ TOUCH%TOUCH_always% MOVE$MOVE_RLEFT$ CHAMBER2 " "roll_left_out" = " BC$BC_left_out1$ ACTIVE$init_always$ IDENT%IDENT_wall% MAT$MAT_RLEFT$ TOUCH%TOUCH_always% MOVE$MOVE_RLEFT$ CHAMBER2 " ... "roll_right_front" = " BC$BC_roll_side$ ACTIVE$init_always$ IDENT%IDENT_slip% MAT$MAT_RRIGHT$ TOUCH%TOUCH_always% MOVE$MOVE_RRIGHT$ CHAMBER3 " "roll_right_back" = " BC$BC_roll_side$ ACTIVE$init_always$ IDENT%IDENT_slip% MAT$MAT_RRIGHT$ TOUCH%TOUCH_always% MOVE$MOVE_RRIGHT$ CHAMBER3 " "roll_right_in" = " BC$BC_roll_in$ ACTIVE$init_always$ IDENT%IDENT_wall% MAT$MAT_RRIGHT$ TOUCH%TOUCH_always% MOVE$MOVE_RRIGHT$ CHAMBER3 " "roll_right_out" = " BC$BC_right_out1$ ACTIVE$init_always$ IDENT%IDENT_wall% MAT$MAT_RRIGHT$ TOUCH%TOUCH_always% MOVE$MOVE_RRIGHT$ CHAMBER3 " #ALIAS_points "Point_H_Curve1" = " ACTIVE$init_always$ SMOOTH_LENGTH$H_CURVE1$ MOVE$NO_MOVE$ CHAMBER1 " "Point_P_100" = " ACTIVE$init_always$ SMOOTH_LENGTH$P_100$ MOVE$NO_MOVE$ CHAMBER2 " "Point_P_200" = " ACTIVE$init_always$ SMOOTH_LENGTH$P_200$ MOVE$NO_MOVE$ CHAMBER3 "

Please observe, that "roll_left_out" and "roll_right_out" (the outer skins of the rolls) are defined twice, as they are part of the rolls as well as of the liquid melt. Especially have a look at the temperature boundary conditions for the contact between the melt and the rolls, where we prescribe a big heat transfer coefficient:

BCON_CNTCT($BC_left_out1$,%ind_T%) = ( %BND_ROBIN%, 200000, 0, 0 )# almost perfect heat contact BCON_CNTCT($BC_left_out2$,%ind_T%) = ( %BND_ROBIN%, 200000, 0, 0 )# almost perfect heat contact BCON_CNTCT($BC_right_out1$,%ind_T%) = ( %BND_ROBIN%, 200000, 0, 0 )# almost perfect heat contact BCON_CNTCT($BC_right_out2$,%ind_T%) = ( %BND_ROBIN%, 200000, 0, 0 )# almost perfect heat contact

In order to release the liquid melt from the rolls, we have to provide tear-off criteria

BC_TearOffCriterion($BC_left_out2$) = equn{$TearOff$} BC_TearOffCriterion($BC_right_out2$) = equn{$TearOff$}

Note: In order to reproduce Figure 25, load the state file tut10_figure25.pvsm in ParaView and choose 'Search files under specified directory'. Then, select the correct data directory (MESHFREE results folder).