P hoenics I nput L anguage: PIL

1. Phoenics Input Language: PIL • The PIL language was developed during the first stages of PHOENICS development. • In that time there were no graphics interface and the user had to communicate with the Main program by means of a Q1 file written in PIL. • The PIL is quite similar to FORTRAN and is the Q1 input language. • Despite of the graphics interface development, the PIL is still today largely used because it still can do tasks not possible in VR interface for instance. • For experienced users it is faster to modify Q1 rather than go to VR interface. • At last, it is the most powerfull tool to design your own development.

2. Q1 and RESULT Files • The q1 is the input file. One may written a q1 using VR or typing from the key board the PIL statements. • A balanced use of the two editors is very convenient. • The result file is also written in PIL and echoes all the q1 statements. • Most of the times the q1 statements are functions which, by their turn, became multiple arguments in RESULT file. • We will see some examples in the following slides.

3. q1 PHOTON RESULT PHI XYZ Earth EARDAT AUTOPLOT Satellite GREX (ground examples) Arquivos FORTRAN GRND (user code) NotePad PIL / FORTRAN Schematic of the three main blocks of PHOENICS MENU v 2.0 Virtual Reality v 3.0 VR VIEWER PÓS PROCESSAMENTO: Apresentação Resultados PRÉ PROCESSAMENTO:Definição Problema MAIN: simulação

4. Data input in PHOENICS is organized in 25 groups. • GROUP 1 - Title & Preliminaries • GROUPS 2 thru 6 - Transience & grid specification • GROUPS 7 and 8 - Solver options and controls • GROUP 9 - Properties • GROUP 10 - Interphase transport coefficients • GROUP 11 - Initialization and porosities • GROUP 12 - Coefficients of convection and diffusion • GROUP 13 - Source and boundary conditions • GROUP 14 - Parabolic runs • GROUPS 15 thru 18 - Convergence controls • GROUP 19 - Calls to ground • GROUP 20 thru 25 - Print outs & monitoring controls

5. Z Y CASE STUDY : 1D TRANSIENT CONDUCTION IN A FIN (LE#3 ex. #1) We are going to get acquainted with the PHOENICS Groups and PIL Language by inspecting the echoed groups in Q1 and RESULT files from this case study.

6. GROUP 1 Run titles and other preliminaries • PHOENICS is arranged so as to make it possible to set up and execute a series of computer runs, a facility that is often exploited when 'parametric studies' are required. Each run then needs to be identified by a number; and it is usually convenient to give each run its own title. GROUP 1 is the place for such labeling operations. • Declarations such as REAL(...), CHAR(....), ARRAY(....,...), for variables which they user intends to use, are also best made here. However, so long as the declaration statement s appear in the Q1 file ABOVE the point of their first use, they can appear in any group.

7. GROUP 2 Transience: time-step specification • PHOENICS can simulate both steady-state and transient phenomena. • For the former, no entry is required in GROUP 2; otherwise, data items relating to time dependence must be supplied here.

8. GROUPS 3, 4 and 5 x-, y- and z-direction grid specifications • PHOENICS can represent phenomena in 1, 2 or 3 space dimensions. Provision is therefore made for setting up 'grids' in three directions, designated x, y and z; and each is dealt with separately. • x, y and z are all distances in the standard settings, measured in meters; however, x may be caused, by setting XCYCLE=T, to represent an angular coordinate; and similar changes can be effected, with more difficulty, for y and z.

9. GROUP 6 Body-fitted coordinates or grid distortion • BFC=T, if body-fitted coordinates are required, is set here. If it is, further commands such as GSET(....) usually follow, for specifying the grid.

10. GROUP 7 Variables stored, solved and named • PHOENICS has been set up so that it can solve differential equations for up to 50 dependent variables simultaneously with especial ease; but more can also be dealt with. • What variables are to be solved is settled in GROUP 7; also, to some extent, HOW they are to be solved. • If variables are to be given storage space but not actually solved, as is often convenient for important auxiliary variables, this information is also conveyed here.

11. GROUP 8 Terms (in differential equations) and devices • The typical differential equation which PHOENICS solves has terms corresponding to transient, convection, diffusion and source-sink effects; but not all the variables of a given problem exhibit all the effects. • GROUP 8 allows distinctions to be made between the variables in these respects. This facility can also be exploited as an economy measure, when some effects which are present are so small as to be negligible; for then they can be omitted entirely, with consequent saving of computation time. • Should users wish to intervene, through GROUND, in the procedures for setting up and solving the flow-simulating equations, they can do so by setting certain 'switches' in GROUP 8 of SATELLITE, and then providing corresponding coding sequences in GROUP 8 of GROUND.

12. GROUP 9 Properties of the medium (or media) • It is necessary to inform PHOENICS about the physical properties of the medium in which the flow to be simulated actually occurs; and, since the computer code is equipped for the simulation of two-phase (ie two-interpenetrating-media) phenomena, two sets of property data may require to be specified. The properties in question may be thermodynamic (eg density), transport (eg viscosity), or inter-phase (eg saturation enthalpy). • GROUP 9 is the place for such data items.

13. GROUP 10 Interphase-transfer processes and properties • A special group, number 10, has been set aside for those property- data items which relate to the interactions between phases which are both present in the same location and at the same time. The interactions may involve heat transfer, mass transfer and momentum transfer; and information may also need to be supplied about the thermodynamic-equilibrium and chemical-kinetic natures of the interactions.

14. GROUP 11 Initialization of variable or porosity fields • When PHOENICS is solving a problem involving time-dependence, the problem specification usually starts with a statement about what values of all the dependent variables pertain, to all the points in the space in question, at the first instant to be considered. These 'initial values' can be supplied among the data items of GROUP 11. • Even in problems of steady-state character, because PHOENICS proceeds in an iterative manner, initial values must be supplied. These are the 'first guesses', rather than problem-specifying data; and their values should not ordinarily influence the final solution. However, they are supplied in precisely the same way as are the initial values of true time-dependent phenomena. • Among the variables which may be initialized in this way are the so-called 'porosities', which indicate what fractions of the areas and volumes of the computational cells are actually accessible to the fluid. These are not ordinarily dependent variables of differential equations; but they may be stored and handled within PHOENICS as though they were.

15. GROUP 12 Convection and diffusion adjustments • The above-mentioned 'porosities' limit the magnitudes of the relevant fluxes of heat, mass and momentum uniformly in respect of all dependent variables. However, it may be useful sometimes to distinguish one variable from another, as when, for example, a membrane is introduced which is permeable to heat and some constituents of a mixture, but impermeable to other constituents.

16. GROUP 13 Boundary conditions and special sources • What makes one flow phenomenon differ from another is partly the properties of the medium, partly the initial conditions and partly the boundary conditions (which, despite their name, may be located inside the flow domain). PHOENICS is therefore supplied, in the sections appropriate to data-input GROUP 13, with an extensive set of procedures which permit the relevant information to be supplied. • All such boundary and internal conditions are treated, in PHOENICS, as sources and sinks; therefore the same data-input procedures are employed whenever any source/sink information is to be transmitted. GROUP 13 may thus also be used for representing generation terms in a turbulence-energy equation, or for introducing novel formulations for chemical-reaction rates.

17. GROUP 14 Downstream pressure for PARAB=T • PHOENICS can simulate fluid-flow phenomena of the kind known as 'parabolic', for example the development of a boundary layer on an airfoil. Some of these phenomena require, for their complete simulation, the specification of the way in which the fluid pressure varies with downstream (ie z-direction) distance. GROUP 14 has been provided as the repository of information of this kind.

18. GROUP 15 Termination of sweeps • PHOENICS solves its equations by guess-and-correct procedures, which, provided that they are indeed converging, cause the imbalances in the finite-domain equations to become smaller and smaller. • There is no limit to the number of cycles of successive adjustments that PHOENICS can perform; but there is a limit to how many are worth performing. It is for the user to provide PHOENICS with information about the latter limit; and GROUP 15 is the place where this provision should be made.

19. GROUP 16 Termination of iterations • There are iterations of two main kinds in PHOENICS: the 'outer iterations' or 'sweeps' , which are the concern of GROUP 15; and the 'inner iterations', for which the limiting information is supplied in GROUP 16. The former are concerned with eliminating imbalances deriving from the non-linearities, while the latter are associated with the fact that PHOENICS uses iterative procedures for solving even the linear equations which arise (in large numbers) at various points in the solution procedure.

20. GROUP 17 Under-relaxation devices • In order to ensure convergence, iterative solution procedures for non-linear sets may require the judicious introduction of 'under- relaxation' practices. For linear equations, on the other hand, over-relaxation may cause convergence to be attained more rapidly. • PHOENICS possesses several features which allow under- and over- relaxation to be practised, and in a rather discriminating way. GROUP 17 is the place at which these devices are normally activated.

21. GROUP 18 Limits on variables or increments to them • During the course of a sequence of outer-iteration cycles, values of dependent variables may wander rather far from both their initial values and from the values which are finally found to satisfy all the equations, ie from the solution. At times, this 'wandering' may become excessive; and, if no limits are placed on it, the result may be that 'divergence' occurs; no solution of the equations is then arrived at. • The latter outcome can however often be prevented if PHOENICS is informed about the upper and lower limits, relevant to each dependent variable separately, which the said variables should not exceed. These limits may be set by the user, possibly on physical grounds (which preclude negative densities, for example), or perhaps to express other insights or desires which he possesses. GROUP 18 provides the necessary opportunities.

22. GROUP 19 Data communicated by SATELLITE to GROUND • PHOENICS users can, if they wish, modify or add to the GROUND sub- routines which are attached to the EARTH module; and spare variables such as RSG's (Reals connecting Satellite and Ground), LSG's (Logicals connecting Satellite and Ground), ISG's (Integers...) and CSG's (Characters ....) are provided to enable them to transmit information from the SATELLITE to the coding which they have introduced. • These are usually set in Group 19.

23. GROUPS 20 to 24 • Preliminary-, variable-, spot-value- and field- print-out; plot control and dumps for restarts • Quite apart from the ability to accept special print-out instructions via arrangements made through GROUP 19, PHOENICS possesses extensive controls for its already-built-in print-out procedures. The controls are distributed between the last five data-input groups. • GROUP 20 controls the extent to which EARTH prints out data-input summaries before execution begins. GROUP 21 accepts information about the extent and frequency of the print-out of dependent- variable fields, while GROUP 22 does the same for the print-out of the single-point values which are used for monitoring the course of the solution process. • GROUP 23 is the repository of information about which types of print-out are elicited for which stored variable; and, finally, GROUP 24 concerns that special kind of information 'dump' which permits continuation of an EARTH computation which has been paused, either with or without changed arrangements for print-out.

24. RESIDUAL AND NET SOURCES IN RESULT FILE Whole-field residuals before solution with resref values determined by EARTH & resfac= 1.000000E-02 variable resref (res sum)/resref (res sum) TEM1 4.625E-02 4.551E-05 2.105E-06 Nett source of TEM1 at patch named: OB1 (LOW ) = 3.272568E-01 Nett source of TEM1 at patch named: OC2 (NORTH ) =-2.624250E-01 pos. sum= 3.272568E-01 neg. sum=-2.624250E-01 nett sum= 6.483176E-02

25. CPU PERFORMANCE IN RESULT FILE • ************************************************************ • SATLIT RUN NUMBER = 1 ; LIBRARY REF.= 0 • Run completed at 20:34:06 on Tuesday, 12 April 2005 • MACHINE-CLOCK TIME OF RUN = 3 SECONDS. • TIME/(VARIABLES*CELLS*TSTEPS*SWEEPS*ITS) = 5.000E-04

26. ************************************************************ Group 1. Run Title TEXT(LE#3 - EX#1 ) ************************************************************ Group 2. Transience STEADY=F * Set overall time and no. of steps RSET(U,0.000000E+00,1.000000E+03,100) * Modify regions ************************************************************ Groups 3, 4, 5 Grid InformationNEXT * Overall number of cells, RSET(M,NX,NY,NZ,tolerance) RSET(M,1,1,20) * Set overall domain extent: * xulast yvlast zwlast name XSI= 6.283190E+00; YSI= 5.000000E-03; ZSI= 1.000000E-01 RSET(D,CHAM ) * Cylindrical-polar grid CARTES=F ************************************************************ Group 6. Body-Fitted coordinates ************************************************************

27. Group 24. Dumps For Restarts NEXT NOWIPE = T IDISPA = 10 ;IDISPB = 1 ;IDISPC = 100 CSG1 ='F' GVIEW(P,-8.114650E-01,-6.012347E-02,-5.813001E-01) GVIEW(UP,-5.798833E-01,-4.060527E-02,8.136870E-01) > DOM, SIZE, 6.283190E+00, 5.00E-03, 1.00E-01 > DOM, MONIT, 3.141590E+00, 2.50E-03, 9.250E-02 > DOM, SCALE, 1.00E+00, 1.00E+00, 1.00E+00 > DOM, SNAPSIZE, 1.000E-02 > DOM, RELAX, 5.000E-01

28. ************************************************************ Group 7. Variables: STOREd,SOLVEd,NAMEdNEXT ONEPHS = T * Non-default variable names NAME(148) =PRPS ; NAME(149) =SPH1 NAME(150) =TEM1 * Solved variables list SOLVE(TEM1) * Stored variables list STORE(SPH1,PRPS) * Additional solver options SOLUTN(TEM1,Y,Y,Y,N,N,Y) ************************************************************ Group 8. Terms & DevicesNEXT TERMS (TEM1,Y,Y,Y,Y,Y,Y) ************************************************************

29. ************************************************************ Group 9. PropertiesNEXT SETPRPS(1, 67) RHO1 = 9.982300E+02 PRESS0 = 1.000000E+05 TEMP0 = 2.730000E+02 CP1 = 4.181800E+03 ENUL = 1.006000E-06 ;ENUT = 0.000000E+00 DVO1DT = 1.180000E-04 PRNDTL(TEM1) = -5.970000E-01 ************************************************************ Group 10.Inter-Phase Transfer Processes ************************************************************ Group 11.Initialise Var/Porosity FieldsNEXT FIINIT(PRPS) = 6.700000E+01 ;FIINIT(SPH1) = 4.730000E+02 FIINIT(TEM1) = 2.000000E+01 No PATCHes used for this Group INIADD = F ************************************************************ Group 12. Convection and diffusion adjustments No PATCHes used for this Group

30. ************************************************************ Group 13. Boundary & Special SourcesNEXT No PATCHes used for this Group EGWF = T ************************************************************ Group 14. Downstream Pressure For PARAB ************************************************************ Group 15. Terminate SweepsNEXT LSWEEP = 1000 RESFAC = 1.000000E-02 ************************************************************ Group 16. Terminate IterationsNEXT ************************************************************ Group 17. RelaxationNEXT ************************************************************ Group 18. LimitsNEXT ************************************************************ Group 19. EARTH Calls To GROUND StationNEXT USEGRD = T ;USEGRX = T ASAP = T IDISPB = 1 ;IDISPC = 100 CSG1 ='F' ************************************************************

31. Group 24. Dumps For Restarts NEXT > OBJ1, NAME, LOW > OBJ1, POSITION, 0.00E+00, 0.00E+00, 0.00E+00 > OBJ1, SIZE, 6.283190E+00, 5.00E-03, 0.00E+00 > OBJ1, CLIPART, polcu2 > OBJ1, ROTATION24, 1 > OBJ1, TYPE, PLATE > OBJ1, SURF_TEMP, 0.00E+00, 1.00E+02 > OBJ2, NAME, NORTH > OBJ2, POSITION, 0.00E+00, 5.00E-03, 0.00E+00 > OBJ2, SIZE, 6.283185E+00, 0.00E+00, 1.00E-01 > OBJ2, CLIPART, polcu2 > OBJ2, ROTATION24, 1 > OBJ2, TYPE, PLATE > OBJ2, LINR_HEAT, 1.075E+01, 2.00E+01 STOP

32. ARQUIVO RESULT • ‘ECOA’ TODOS OS COMANDOS EMITIDOS DO Q1 • ELE ESCREVE NUMA LINGUAGEM ‘PIL’ BÁSICA • NOTE QUE OS COMANDOS DO Q1 SÃO ‘RE-INTERPRETADOS’ PARA APARECER NO RESULT • DEVE-SE DESTACAR QUE ELES SÃO TOTALMENTE EQUIVALENTES. • SE VOCÊ UTILIZASSE OS COMANDOS ECOADOS NO RESULT NO Q1 O RESULTADO SERIA O MESMO • MUITAS VEZES OS COMANDOS DO Q1 SÃO MAIS CONVENIENTES POR SEREM MAIS ‘COMPACTOS’.

33. ************************************************************ Group 2. Transience STEADY = F * Set overall time and no. of steps TFIRST = 0.000000E+00 ;TLAST = 1.000000E+03 LSTEP = 100 TFRAC ( 1) = 1.000000E-02 ;TFRAC ( 2) = 2.000000E-02 TFRAC ( 3) = 3.000000E-02 ;TFRAC ( 4) = 4.000000E-02 TFRAC ( 5) = 5.000000E-02 ;TFRAC ( 6) = 6.000000E-02 TFRAC ( 7) = 7.000000E-02 ;TFRAC ( 8) = 8.000001E-02 TFRAC ( 9) = 9.000000E-02 ;TFRAC ( 10) = 1.000000E-01 . . . TFRAC ( 93) = 9.300001E-01 ;TFRAC ( 94) = 9.400001E-01 TFRAC ( 95) = 9.500000E-01 ;TFRAC ( 96) = 9.600000E-01 TFRAC ( 97) = 9.700000E-01 ;TFRAC ( 98) = 9.800000E-01 TFRAC ( 99) = 9.900001E-01 ;TFRAC (100) = 1.000000E+00 ************************************************************

34. Group 3. X-Direction Grid SpacingBACK CARTES = F NX = 1 XULAST = 6.283190E+00 ************************************************************ Group 4. Y-Direction Grid Spacing NY = 1 YVLAST = 5.000000E-03 ************************************************************ Group 5. Z-Direction Grid Spacing PARAB = F NZ = 20 ZWLAST = 1.000000E-01 ZFRAC ( 1) = 5.000000E-02 ;ZFRAC ( 2) = 9.999999E-02 ZFRAC ( 3) = 1.500000E-01 ;ZFRAC ( 4) = 2.000000E-01 . . . ZFRAC (17) = 8.500000E-01 ;ZFRAC (18) = 9.000000E-01 ZFRAC (19) = 9.500000E-01 ;ZFRAC (20) = 1.000000E+00 ************************************************************

35. ************************************************************ Group 7. Variables: STOREd,SOLVEd,NAMEdBACK ONEPHS = T NAME(148) =PRPS ;NAME(149) =SPH1 NAME(150) =TEM1 * Y in SOLUTN argument list denotes: * 1-stored 2-solved 3-whole-field * 4-point-by-point 5-explicit 6-harmonic averaging SOLUTN(PRPS,Y,N,N,N,N,Y) SOLUTN(SPH1,Y,N,N,N,N,N) SOLUTN(TEM1,Y,Y,Y,N,N,Y) PRPS = 148 ************************************************************ Group 8. Terms & DevicesBACK * Y in TERMS argument list denotes: * 1-built-in source 2-convection 3-diffusion 4-transient * 5-first phase variable 6-interphase transport TERMS (TEM1,Y,N,Y,Y,Y,N) DIFCUT = 5.000000E-01 ;ZDIFAC = 1.000000E+00 GALA = F ;ADDDIF = F ISOLX = 0 ;ISOLY = 0 ;ISOLZ = 1 ************************************************************

36. ************************************************************ Group 9. PropertiesBACK RHO1 = 9.982300E+02 ;TMP1 = 0.000000E+00 EL1 = 0.000000E+00 TSURR = 0.000000E+00 ;TEMP0 = 2.730000E+02 PRESS0 = 1.000000E+05 DVO1DT = 1.180000E-04 ENUL = 1.006000E-06 ;ENUT = 0.000000E+00 PRNDTL(TEM1) = -5.970000E-01 PRT (TEM1) = 1.000000E+00 CP1 = 4.181800E+03 ;CP2 = 4.181800E+03 ************************************************************ Group 10.Inter-Phase Transfer Processes ************************************************************

37. ************************************************************ Group 11.Initialise Var/Porosity FieldsBACK FIINIT(PRPS) = 6.700000E+01 ;FIINIT(SPH1) = 4.730000E+02 FIINIT(TEM1) = 2.000000E+01 No PATCHes yet used for this Group INIADD = F FSWEEP = 1 NAMFI =CHAM ************************************************************ Group 12. Patchwise adjustment of terms Patches for this group are printed with those for Group 13. Their names begin either with GP12 or &

38. ************************************************************ Group 13. Boundary & Special SourcesBACK Parent VR object for this patch is: LOW PATCH(OB1 ,LWALL , 1, 1, 1, 1, 1, 1, 1, 100) COVAL(OB1 ,TEM1, 1.000000E+00, 1.000000E+02) Parent VR object for this patch is: NORTH PATCH(OB2 ,NWALL , 1, 1, 1, 1, 1, 20, 1, 100) Parent VR object for this patch is: NORTH PATCH(OC2 ,NORTH , 1, 1, 1, 1, 1, 20, 1, 100) COVAL(OC2 ,TEM1, 1.075000E+01, 2.000000E+01) XCYCLE = F EGWF = F

39. ************************************************************ Group 14. Downstream Pressure For PARAB ************************************************************ Group 15. Terminate SweepsBACK LSWEEP = 1000 ;ISWC1 = 1 LITHYD = 1 ;LITFLX = 1 ;LITC = 1 ;ITHC1 = 1 SELREF = T RESFAC = 1.000000E-02 ************************************************************ Group 16. Terminate IterationsBACK LITER (TEM1) = 20 ENDIT (TEM1) = 1.000000E-03 ************************************************************ Group 17. RelaxationBACK RELAX(PRPS,LINRLX, 1.000000E+00) RELAX(SPH1,LINRLX, 1.000000E+00) RELAX(TEM1,FALSDT, 1.000000E+09) OVRRLX = 0.000000E+00 EXPERT = F ;NNORSL = F

40. ************************************************************ Group 18. LimitsBACK VARMAX(PRPS) = 1.000000E+10 ;VARMIN(PRPS) =-1.000000E+10 VARMAX(SPH1) = 1.000000E+10 ;VARMIN(SPH1) =-1.000000E+10 VARMAX(TEM1) = 1.000000E+10 ;VARMIN(TEM1) =-1.000000E+10 ************************************************************ Group 19. EARTH Calls To GROUND StationBACK USEGRD = T ;USEGRX = T ASAP = T IDISPB = 1 ;IDISPC = 100 CSG1 ='F' SPEDAT(SET,DOMAIN,PHASE_1_MAT,I,67) SPEDAT(SET,OBJNAM,^OB1,C,LOW) SPEDAT(SET,IGESTYPE,^OB1,C,PLATE) SPEDAT(SET,OBJNAM,^OB2,C,NORTH) SPEDAT(SET,IGESTYPE,^OB2,C,PLATE) SPEDAT(SET,OBJNAM,^OC2,C,NORTH) SPEDAT(SET,IGESTYPE,^OC2,C,USER_DEFINED) SPEDAT(SET,MATERIAL,67,L,T)

41. END