label TOP q1quit=t;dmpstk=f;nocomm=t;nocopy=t;nowipe=t rset(v,0) Preliminaries : Satelite subroutine sat calls CHKINP for FORTRAN string comparison namsat=chkc Set up 4 character values, and one logical. Logical is set true immediately prior to satrun call, and is returned false Character strings are set to give prompts and accept data for test boolean(log1) char(cvl1,cvl2,cvl3,cvl4);cvl3='Correct!' QCOM statements are used to annotate the Q1 file, DCOM to process command and annotate Q1 file ----- start of tutorial : ----- write group identifiers etc to Q1 file qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 1. Run title and other preliminaries qcom( * display WELCOME TO PIL TUTORIAL NUMBER 2 ******************************** This tutorial continues to teach you the basic PIL commands and specifies a simple problem of flow in circular- polar geometry which can then be run by PHOENICS. The problem being set-up is shown below POLAR GEOMETRY Wall ____________________________ \ / \ / Inlet \ / Outlet \ / \ / \____________/ Wall CALL LOAD_96 The tutorial is configured to expect valid PIL commands to be entered by you at the terminal. String comparison is then undertaken to ensure that you have entered the correct data. As such, it is important to note that the exact numbers are required to be input. * YOU MUST READ the panels presented to you * The form of the PIL commands and other hints are given NB: You can quit the tutorial at any time by entering "quit" CALL LOAD_96 GRID X-Direction Y-Direction XLength : 1.5 YLength : 0.1 No. of regions: 1 No. of regions: 1 No. of cells : 15 No. of cells : -20 Power : 1.0 Power : 1.4 NB. Negative sign on No. of cells in Y indicates that these are symmetrically distributed. CALL LOAD_96 VARIABLES Solved: P1, U1, V1 Stored : ENUT PROPERTIES Turbulence model : k-epsilon Reference pressure (PRESS0): 1.E5 Density (RHO1 ): 1.22 Viscosity (ENUL ): 1.4654E-4 INITIAL FIELDS KE=0.04 ; EP=0.13 CALL LOAD_96 BOUNDARY CONDITIONS All PATCH LOCATIONS ARE: #1,#1,#1,#1,#1,#1,#1,#1 WALL NAME : TOP ; BOT TYPE : NORTH ; SOUTH PIL var Coef Value U1 loglaw 0.0 KE loglaw loglaw EP loglaw loglaw CALL LOAD_96 INLET NAME : INLET TYPE : WEST PIL var Value P1 10.0*rho1 U1 10 V1 0.0 KE 0.04 EP 0.13 CALL LOAD_96 OUTLET NAME : OUT TYPE : EAST PIL var Value P1 0.0 CALL LOAD_96 * Start of Tutorial 2 * * * * EXPECTED title is 'tutorial.2' Group 1 of the Q1 file is used to specify the title of the prediction The title should be a unique identifier. This is presented on PHOTON output, and included in results files. The PIL command to set the title has the syntax: TEXT(Required Text The required text in this case is the title shown above hence the input required at the prompt MUST be text(Tutorial.2 cvl2=text(Tutorial.2 cvl4='Please_enter_the_TEXT_command_to_set_the_title_for_this_case' CALL LOAD_95 qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 2. Transience; time-step specification qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 3. X-direction grid specification qcom( * regions in x = 1 GROUP 2. Transience; time-step specification GROUP 3. X-direction grid specification There are several methods available within PHOENICS to define the computational mesh. This Tutorial will show how to specify a cylindrical polar mesh. The mesh for this tutorial is cylindrical polar, hence we must add a PIL statement as follows: CARTES=F This statement informs PHOENICS that the mesh is cylindrical polar with the following sign convention : X cells going round the circle : Y cells starting at the centre : Z cells runnning along the axis cvl4='Please_indicate_a_cylindrical_polar_prediction' cvl2=cartes=f CALL LOAD_95 Having specified a cylindrical polar geometry, we have to specify how many cells are present around the circumference of the geometry. This is done in a manner similar to piltut.1, where we define the number of regions in the X direction and then use grdpwr to specify the distribution. These region identities are then used to control the mesh spacing according to other PIL commands. The number of regions in each direction is given by a PIL command with the syntax NREGdir=integer number where : dir is T,X,Y, or Z for time,or spatial co-ordinates and the integer is the required number of regions cvl4='Please_set_the_number_of_regions_in_the_x_direction_to_1' cvl2=nregx=1 CALL LOAD_95 * * * * * iregx 1 + grdpwr Having specified the number of regions in X, we now have to specify the cell spacing in each region To do this requires two operations: 1) to identify the relevant region 2) to specify the grid spacing The identification of the relevant region is via a PIL statement with the Syntax IREGdir=integer number where : dir is T,X,Y, or Z for time,or spatial co-ordinates the integer is the required region cvl4='Please_enter_the_index_of_the_first_x_region_to_be_modified' cvl2=iregx=1 CALL LOAD_95 Cell spacing in region 1 is determined via a PIL statement with the syntax: GRDPWR(dir,IC,LENGTH,PWR) where : dir is T,X,Y, or Z for time, and spatial co-ordinates IC is the number of cells in the region LENGTH is the extent of the region PWR is the power that is used to distribute the cells GRDPWR(x,10,1,1.4) would put 10 cells in x over 1 RADIAN, with small cells at the beginning, large cells at the end. Negative powers will put large cells at the beginning! Negative numbers of cells symmetrically place cells according to the power reminder: xlength=1.5; no. of cells = 15; power=1.0 (...and remember....RADIANS now) cvl4='Please_enter_the_distribution_of_cells_in_x_region_1' cvl2=grdpwr(x,15,1.5,1.0) CALL LOAD_95 do jj=1,25 mesg( enddo Congratulations, You have now set the X direction mesh distribution. This mesh will now be shown by use of the view statement. NOTE: we have only defined the mesh in X thus far. please press "enter" to view the mesh thus far and then press "enter" again to continue the tutorial CALL LOAD_96 view(k,1) qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 4. Y-direction grid specification qcom( * regions in y = 1 GROUP 4. Y-direction grid specification Having completed the specification of the X Mesh, running around the circle, The next task is to specify the Mesh in Y, for the radial cells. cylindrical polar gemetries within PHOENICS can either start at the AXIS (0,0,0) or at some nominated 'inner radius'. The inner radius is required for this case, and is specified by a PIL statement with the form: RINNER=val where: val=the inner radius (in metres) cvl4='Please_set_the_inner_radius_for_this_case_to_0.1' cvl2=rinner=0.1 CALL LOAD_95 The next task is to specify the Mesh in Y, and again we will use the method of REGIONS and gridpower Hence, The first step in setting the mesh in Y is to define the number of regions in Y These region identities are then used to control the mesh spacing according to other PIL commands The number of regions in each direction is given by a PIL command with the syntax NREGdir=integer number where : dir is T,X,Y, or Z for time, and spatial co-ordinates the integer is the required number of regions cvl4='Please_set_the_number_of_regions_in_y_to_1' cvl2=nregy=1 CALL LOAD_95 * * * iregy 1 + grdpwr The specification in Y is analogous to that in X. Remember, To do this requires two operations: 1) to identify the region. 2) to specify the grid spacing Remember, the identification of the relevant region is via a PIL statement with the Syntax IREGdir=integer number And the grid spacing is specified with GRDPWR(dir,IC,LENGTH,PWR) where : dir is T,X,Y, or Z for time,or spatial co-ordinates the integer is the current region to be modified IC is the number of cells in the region LENGTH is the cartesian extent of the region positive/negative power expands/contracts cells reminder: ylength=0.1 ; No. of cells =-20; power=1.4 cvl4='Please_enter_the_index_of_the_y_region_to_be_modified' cvl2=iregy=1 CALL LOAD_95 cvl4='Please_enter_the_distribution_of_cells_in_y_region_1' cvl2=grdpwr(y,-20,0.1,1.4) CALL LOAD_95 Congratulations, You have now completed the mesh specification in the XY plane for the tutorial This mesh will now be shown by use of the view statement please press "enter" to view the mesh and then press "enter" again to continue the tutorial CALL LOAD_96 view(k,1) qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 5. Z-direction grid specification qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 6. Body-fitted coordinates or grid distortion qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 7. Variables stored, solved & named qcom( * variables to be solved GROUP 5. Z-direction grid specification GROUP 6. Body-fitted coordinates or grid distortion GROUP 7. Variables stored, solved & named The PHOENICS code requires you to specify which equations are to be solved as the solution proceeds. PHOENICS solves the Navier-Stokes equations for fluid flow using the SIMPLEST scheme. As such, the relevant velocity component for each direction and the pressure are the minimum equations to be solved. The PIL statement has the Syntax SOLVE(variable list) Variables are separated by a comma, and are P1 pressure U1 velocity in X direction V1 velocity in Y direction cvl4='Please_enter_the_names_of_the_variables_to_be_solved' cvl2=solve(p1,u1,v1) CALL LOAD_95 The solution process for the PRESSURE correction can be configured to be "whole field" or slabwise Slabwise solution is the default, and is more suited for thin shear (parabolic), or hyperbolic (supersonic) flows PIL syntax: SOLUTN(var,Y,Y,N,N,N,N) where : var is the variable name, and the six other parameters store,solve,elliptical,jacobi,explicit,harmonic For more information, see the encyclopaedia entry on SOLUTN Elliptical (whole field) pressure fields are normal for general engineering flows, and are essential for flows with recirculations/separations. This case has recirculation, and hence requires an elliptical pressure field. eg: SOLUTN(P1,Y,Y,Y,N,N,N) cvl4='Change_pressure_solver_to_be_whole_field' cvl2=solutn(p1,y,y,y,n,n,n) CALL LOAD_95 other stored variables The PHOENICS code can solve/store up to 50 variables Some of which we have already activated. Storage of auxiliary variables and properties such as density are required according to which problem is being examined. The variables stored can then be under-relaxed if required to assist convergence, and are available for plotting within PHOTON and AUTOPLOT This case has no problems with convergence, but will use the k-epsilon turbulence model, and the auxiliary store for the turbulent viscosity (ENUT) is required The PIL statement for the storage is : STORE(variable list) For more information, see Encyclopaedia entry on STORE cvl4='Please_indicate_variables_to_be_stored' cvl2=store(enut) CALL LOAD_95 qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 8. Terms (in differential equations) & devices qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 9. Properties of the medium (or media) qcom( * reference pressure GROUP 8. Terms (in differential equations) & devices GROUP 9. Properties of the medium (or media) PHOENICS can model fluids with fluid properties that vary,for example, density as a function of temperature and pressure The Auxiliary equations used for relationships quite often require reference values to avoid divisions by zero and to minimise rounding errors. For this case, we do NOT vary the density, but as a measure of "Good Practice" we should set a reference pressure. The PIL Syntax for setting a reference pressure is: PRESS0=required real number ( reminder ref. pressure is 1.e5 ) cvl4='Please_set_the_reference_pressure' cvl2=press0=1.e5 CALL LOAD_95 fluid density PHOENICS has default values for typical variables such as density, laminar viscosity etc. As mentioned in the previous panel, it is possible to specify relationships for these parameters. For the purpose of this tutorial, the density is constant, and its value must be specified. The PIL statement : RHO1=real value will specify a constant density throughout the flow domain. (Reminder density=1.22) cvl4='Please_set_the_fluid_density' cvl2=rho1=1.22 CALL LOAD_95 reference laminar viscosity For a similar reason, we must specify a value for the Laminar viscosity Constant values are specified via a PIL statement: ENUL=real number (Reminder viscosity of fluid is 1.465e-5) cvl4='Please_set_the_reference_laminar_viscosity' cvl2=enul=1.465e-5 CALL LOAD_95 activate turbulence models PHOENICS can use several models of turbulence. The PIL statement to activate a turbulence model is: TURMOD(text) where text is: KLMODL - The Prandtl energy model KEMODL - The Kolmorogov k-epsilon model (which solves KE and EP) Other models are available, such as fixed viscosity (PIL: ENUT=required viscosity) Laminar (PIL: ENUT=0.0) cvl4='Please_activate_the_k-epsilon_turbulence_model' cvl2=turmod(kemodl) CALL LOAD_95 qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 10. Inter-phase-transfer processes and properties qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 11. Initialization of variable or porosity fields qcom( * set initial fields PHOENICS uses an iterative solution process to reach the predicted flow. As such, some guesses to the initial fields should be supplied to the iterative solver. All initial fields are set to 1.e-10 by default If this value is inapropriate for any variable then we can set these to suit. with the PIL statement FIINIT(var)=required value eg: FIINIT(U1)=100 sets uniform U1 velocity of 100 ms-1 cvl4='Please_set_initial_field_value_of_0.04_for_ke' cvl2=fiinit(ke)=0.04 CALL LOAD_95 do jj=1,25 mesg( enddo It is normally good practice to set initial fields for both ke and ep to minimise convergence problems cvl4='Please_set_initial_field_value_of_0.13_for_epsilon' cvl2=fiinit(ep)=0.13 CALL LOAD_95 qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 12. Patchwise adjustment of terms qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 13. Boundary conditions and special sources qcom( * Having specified the geometry and the fluid properties we must now indicate the locations of relevant boundaries and what exactly is happening at each boundary. This tutorial will introduce three types of boundary condition * INLETs where fluid will enter the domain * OUTLETS where fluid leaves the domain * Wall friction There are numerous methods and types of boundary specification the methods demonstrated in this tutorial are only a small sub-set of the full range. CALL LOAD_96 GROUP 10. Inter-phase-transfer processes and properties GROUP 11. Initialization of variable or porosity fields GROUP 12. Patchwise variation of terms GROUP 13. Boundary conditions and special sources Boundary conditions are located within the computational volume by the pil statements with the form PATCH(name,type,ixf,ixl,iyf,iyl,izf,izl,itf,itl) where: name is a unique text identifier to link patches and the values being set on the patch. type is the relevant cell face area, volume etc. ixf, etc are region indices if prefixed by a #, or else CELL indices. example: INLET(IN,LOW,1,NX,#1,#2,1,1,#1,#1) sets an inlet patch on the low cell faces for all x cells in the first two regions in Y (reminder Inlet is called INLET, is on the west side of the first region in X, Y and Z) cvl4='Please_set_name,_type_and_location_of_the_inlet' cvl2=inlet(inlet,west,#1,#1,#1,#1,#1,#1,#1,#1) CALL LOAD_95 Having specified the patch location, we now have to specify what mass flows etc are present in the inlet patch. Mass flow rates are specified by adding a source to P1 the pressure correction equation. The source within PHOENICS is linearised to have a coefficient and value. The magnitude of the coefficient is assumed for the INLET style of PATCH, and the value must be mass per unit area. Other variables are just set to the required value VALUE(name,variable,value) where: name is used to link value to the patch. Variable is the relevant equation eg. P1 Value is the required flux (reminder the flow rate is 10.0*rho1; inlet velocity is 10.0) cvl4='Please_set_mass_flow_rate_for_inlet_called_inlet' cvl2=value(inlet,p1,10.0*rho1) CALL LOAD_95 cvl4='Please_set_u_velocity_component_for_inlet_to_10.0' cvl2=value(inlet,u1,10.0) CALL LOAD_95 cvl4='Please_set_v_velocity_component_for_inlet_to_0.0' cvl2=value(inlet,v1,0.0) CALL LOAD_95 cvl4='Please_set_kinetic_energy_entrained_at_the_inlet_to_0.04' cvl2=value(inlet,ke,0.04) CALL LOAD_95 cvl4='Please_set_epsilon_being_entrained_at_the_inlet_to_0.13' cvl2=value(inlet,ep,0.13) CALL LOAD_95 congratulations.... you are really quite good at this now !! Having specified the the inlet patch, we now have to specify the outlet patch. Regions of outflow are normally specified by regions of nomimally constant pressure in a manner similar to inlet above, but the patch name is OUTLET. example: OUTLET(OUT,HIGH,1,NX,#1,#2,NZ,NZ,#1,#1) sets an outlet over all x, first two regions in Y last Z for the first time region (reminder outlet is called out and is on the east of the domain, extending over region 1 in y and z) cvl4='Please_set_name,type_and_location_of_the_outlet' cvl2=outlet(out,east,#1,#1,#1,#1,#1,#1,#1,#1) CALL LOAD_95 Again, on outlet boundaries, Mass flow rates etc are linearised to have a coefficient and value. At an outlet, only the relative pressure need be set - all other values are internal, and hence known to EARTH. Required pressure values are set using : VALUE(name,P1,value) where: name is used to link value to the patch. value is the external pressure, relative to PRESS0 cvl4='Please_set_nominal_pressure_on_outlet_boundary_to_0.0' cvl2=value(out,p1,0.0) CALL LOAD_95 Having specified the inlet and exit patches, we now have to specify wall friction. Regions with wall friction can be specified using a PATCH. example: PATCH(TOP,NWALL,1,NX,#1,#1,1,NZ,#1,#1) sets a north wall over all x, last cell in Y, all Z for the first time region the type is NWALL, SWALL EWALL,WWALL,HWALL or LWALL as required, but ONLY for wall regions. These are special names used to identify regions where the distance from wall to cell centre is important (reminder, wall is called TOP and is on the North part of the domain, extending in all x-regions) cvl4='Please_set_name_type_and_location_of_the_top_wall' cvl2=patch(top,nwall,#1,#1,#1,#1,#1,#1,#1,#1) CALL LOAD_95 The wall condition must be specified in the linearised form having a coefficient and value. The magnitudes of the coefficients are NOT KNOWN for the formal PATCH statement, and we use COVAL statements to specify the required data COVAL(name,variable,COefficient,VALue) where: name is used to link value to the patch. Variable is the relevant equation eg. P1 Coeffficient can be set as follows: Coef, influence on prediction blasius Blasius law loglaw Log law genlaw Generalised log law Value Velocities Wall speed. ke-ep loglaw or genlaw Bounds the Ke and ep equations For this wall the log law method is to be activated. cvl4='Please_set_the_coval_for_the_velocity_parallel_to_the_wall' cvl2=coval(top,u1,loglaw,0.0) CALL LOAD_95 cvl4='Please_set_the_coval_for_the_kinetic_energy_boundary' cvl2=coval(top,ke,loglaw,loglaw) CALL LOAD_95 cvl4='Please_set_the_coval_for_the_dissipation_boundary' cvl2=coval(top,ep,loglaw,loglaw) CALL LOAD_95 CONGRATULATIONS. You have set the three types of Boundary to be covered in this tutorial. All other boundaries ( one wall in this case ) are being set for you. CALL LOAD_96 dcom(patch(bot,swall,#1,#1,#1,#1,#1,#1,#1,#1) dcom(coval(bot,u1,loglaw,0.0) dcom(coval(bot,ke,loglaw,loglaw) dcom(coval(bot,ep,loglaw,loglaw) qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 14. Downstream pressure for PARAB=.TRUE. qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 15. Termination of sweeps qcom( * GROUP 14. Downstream pressure for PARAB=.TRUE. GROUP 15. Termination of sweeps PHOENICS is an iterative code that proceeds from your first guess to a converged prediction. For general engineering problems, the "whole field" pressure is likely to be used, and the iterative process can be described as follows: 1) A series of "sweeps" through the domain from IZ = 1 to IZ = NZ. 2) Each Z "slab" is treated in turn to derive velocity updates to satisfy momentum, and the pressure coefficients for the 3D solver 3) The 3D pressure field is solved, and then used to derive velocities that satisfy continuity. For this tutorial, we are only concerned with the overall number of SWEEPS, with the PIL statement LSWEEP=n where n is the integer number of sweeps required. cvl4='Set_the_iteration_sweeps_to_50' cvl2=lsweep=50 CALL LOAD_95 qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 16. Termination of iterations qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 17. Under-relaxation devices qcom( * dcom(real(maxv,minl,relx) dcom(maxv=5.0 dcom(minl=0.1 dcom(relx=10.0 dcom(relax(p1,linrlx,0.8) dcom(relax(u1,falsdt,minl/maxv*relx) dcom(relax(v1,falsdt,minl/maxv*relx) dcom(relax(ke,falsdt,minl/maxv*relx) dcom(relax(ep,falsdt,minl/maxv*relx) qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 18. Limits on variables or increments to them qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 19. Data communicated by satellite to GROUND qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 20. Preliminary print-out qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 21. Print-out of variables qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 22. Spot-value print-out qcom( * dcom(ixmon=5 dcom(iymon=5 dcom(tstswp=-1 qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 23. Field print-out and plot control qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * qcom( * qcom( * GROUP 24. Dumps for restarts qcom( * qcom( * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * You have now completed the tutorial. You may now end satellite and write out the Q1 file, or quit this tutorial. 'Enter' will end the satellite and save the Q1. 'Quit' will quit the tutorial. IMPORTANT!! If you are running from the satellite top menu, and you want to save the Q1 you have generated, you MUST select 'Command mode', NOT 'End satellite' when you return to the top panel, otherwise you will lose your Q1. CALL LOAD_96 goto DONE label QUIT CALL LOAD_97 label DONE ENDMAIN SUBROUTINE LOAD_95 L($095) ENDSUB SUBROUTINE LOAD_96 L($096) ENDSUB SUBROUTINE LOAD_97 L($097) ENDSUB