Encyclopaedia Index
(see IMON)
ICEM-CFD... a grid-generation and data-input package, developed by Control Data Corporation.
An interface exists between ICEM and PHOENICS.
See "What's new in PHOENICS 3.3 ".
--------- PIL integer; group 13 ---------
IBUOYA... is used to carry a variable name into GREX to use as a criterion for activating certain storage.
See GREX3 for further information.
--------- PIL integer; group 13 ---------
IBUOYB... is used to carry a variable name into GXBUOY and BFCGR so that the value part of the gravitational source term may be calculated as a linear function of this and one other variable.
See GXBUOY and BFCGR for further information.
--------- PIL integer; group 13 ---------
IBUOYC... is used to carry a variable name into GXBUOY and BFCGR so that the value part of the gravitational source term may be calculated as a linear function of this and one other variable.
See GXBUOY and BFCGR for further information.
------ PIL integer; default=2; group 23 --- -
ICHR....controls the print-out of contour-plot levels as follows,
ICHR=1 signifies that even numbers are used; ICHR=2 signifies that odd numbers are used; ICHR=3 means that both even and odd numbers are used.
--------- PIL integer; group 8 ----------
ICNGRA... is used, when the Conjugate Gradient solver in GXCNGR is activated, to select whether a preconditioning is (ICNGRA=1) or is not (ICNGRA<>1) to be used.
--------- PIL integer; group 8 ----------
ICNGRB... is used to select the first variable, in addition to first-phase pressure and velocities, to be solved using the Conjugate Gradient solver, GXCNGR.
--------- PIL integer; group 8 ----------
ICNGRC... is used to select the last variable, in addition to first-phase pressure and velocities, to be solved using the Conjugate Gradient solver, GXCNGR.
----------- PIL integer Switch ----------
ICOLOA... is used to activate the interpolation schemes for the cell-face velocities for CCU.
------- PIL integer; groups 1 & 19 ------
IDISPA, when greater than 0, specifies the frequency, in terms of z-steps for PARAB=T and of time steps for STEADY=F, at which x-y fields of variables are dumped to the parphi (or parada) file by way of GXPARA, called from GREX, for plotting by VR-Viewer or PHOTON.
IDISPA also specifies the frequency, in terms of isweeps for steady elliptic simulations, and of time steps for transient calculations, at which fields of variables and the grid are dumped to the PHI(or PHIDA) and XYZ(or XYZDA) files by way of DUMPS, called from GREX, for plotting by way of VR-Viewer or PHOTON.
The names of the dumped files can be customised by setting CSG1 and CSG2 in Q1.
In transient cases, the first character of CSG1 is used together with the timestep number to generate the name of the dumped phi (or phida) file e.g. if CSG1=A, the files will be A1, A2, A3 etc (or A1DA, A2DA for phida files). The files are written at the end of each step. Adding 'IN' after the letter (CSG1=AIN) will cause the initial fields to be dumped to A0.
For BFC cases the first letter of CSG2 (if set) is used to derive the name of the dumped grid file.
In steady cases, CSG1 must be set to SW, otherwise no files will be dumped. The file names will be S1, S2 S3 etc. CSG1=SWIN will generate a file of the initial values, S0.
Setting CSG1=SW in a transient case will cause files to be dumped each for sweep of each timestep, each step overwriting the files from the previous step.
It is the first, i.e. parabolic, mode which is active whenever CSG1 is not set.
--------- PIL integer; group 9 ----------
IDISPB, in addition to specifying the first (z or time) step at which dumping by GXPARA occurs, determines the first sweep or time step at which PHI(or PHIDA) and XYZ(or XYZDA) are dumped by way of DUMPS. The default value of 0 means start at the first sweep or step.
IDISPB was also used in GXHOL to specify, for STEADY cases for which the Height Of Liquid method is activated, the first sweep at which the VFOL variable is updated. See HOL and the encyclopaedia for further information. This use is replaced by SPEDAT(SET,HOL,IFIRST,ifirst)
--------- PIL integer; group 9 ----------
IDISPC, in addition to specifying the last (z or time) step at which dumping by GXPARA occurs, determines the last sweep or time step at which PHI(or PHIDA) and XYZ(or XYZDA) are dumped by way of DUMPS. The default value of 0 means no limit.
IDISPC was also used in GXHOL to specify, for STEADY cases for which the Height Of Liquid method is activated, the frequency in sweeps at which the VFOL variable is updated. See HOL and the encyclopaedia for further information. This use is replaced by SPEDAT(SET,HOL,IFREQU,ifrequ)
--------- PIL integer; group 19 ---------
IDISPD, when greater than 0, specifies the frequency, in terms of z-steps for PARAB=T and of time steps for STEADY=F, at which fields of variables are dumped to the Pxx files and ,for BFC=T, grids are dumped to the Xxx files, for viewing in PHOTON, between the values of IDISPB and IDISPC (See PHENC entries on these)
------ PIL integer; groups 1, 9 & 13 -----
IENUTA... is used to control turbulence-model options, in Satellite, GREX and EARTH.
| IENUTA | Turbulence model |
| 1 | RNG high-Re k-ε model |
| 2 | Chen-Kim high-Re k-ε model |
| 3 | Lam-Bremhorst low-Re k-ε model |
| 4 | Chen-Kim low-Re k-ε model |
| 5 | |
| 6 | Simple eddy-viscosity multiplier for low Reynolds numbers |
| 7 | Two-scale high-Re k-ε model |
| 8 | Two-layer low-Re k-ε model |
| 9 | Another simple eddy-viscosity multiplier for low Reynolds numbers |
| 10 | Wilcox-Kolmogorov high-Re k-ω model |
| 11 | Wilcox-Kolmogorov low-Re k-ω model |
| 12 | MMK high-Re k-ε model |
| 13 | Kato-Launder high-Re k-ε model |
| 14 | Realisable high-Re k-ε model |
| 15 | Wilcox (2008) high-Re k-ω model |
| 16 | Wilcox (2008) low-Re k-ω model |
| 17 | Menter (1992) high-Re k-ω model |
| 18 | Menter (1992) low-Re k-ω model |
| 19 | high-Re k-ω SST model |
| 20 | low-Re k-ω SST model |
IENUTA is not used for the LVEL and constant-effective-viscosity turbulence models."
See help on TURMOD and TURBULence for further information.
---------------- Advanced PIL command --- -
First element of the PIL IF construct.
The PIL IF construct is used in two circumstances. One is to exit from loops (see the entry on LOOP) and the other is the FORTRAN-like IF..THEN..ELSE..ENDIF explained here.
The syntax of the block IF is:
IF <logical expression> THEN
<PIL statements 1>
ELSE
<PIL statements 2>
ENDIF
For example: IF (NX.GT.1) THEN + SOLVE(U1) -----> PIL statement ELSE + SOLVE(V1) -----> PIL statement ENDIF
The <logical expression> has a syntax and capability are very similar to the corresponding FORTRAN construct, with the following differences:
IFs can be nested to a maximum depth of 20.
This can be achieved by placing the following statement in the q1 file:
SPEDAT(MONITOR,IFREQU,I,the desired value).
-------- PIL integer array; default=0; group -
IG....is an array for transferring to GROUND any integer data that the user may need there.
IGR, an integer set by EARTH to dictate which part (group) of GROUND, GREX3, etc is to be entered.
See PHENC: GROUND.F
----- PIL integer; groups 1, 8, 9, 13 & 19 -
IHOLA... is used, for the Height-Of-Liquid method for free-surface flows, to specify the direction along which the liquid height should be measured. See the help and encyclopaedia entries on Height of liquid for further information.
----- PIL integer; group 13 ---------
ILATGA... is used by GXLATG in the calculation of horizontal gravitational forces resulting from differences in a liquid-layer depth in a pipe. The constant is used to define the direction in which gravity acts. See the help on GRAV for further information.
IMAT is the "material index" showing the position of the property data in the PROPS file. It is conveyed to EARTH via the PRPS field. See PHENC entry PRPS.
------ PIL integer name; group 7 ----------
IMB1.... indicates which whole-field store will be used for the continuity imbalances of phase 1 in response to the command STORE(IMB1). Units are mass/time. Display of the field of continuity imbalances can be useful in isolating areas of the integration domain where the imbalances remaining are largest. Sometimes just a few cells can contain all the errors: once such zones are located, PATCH-wise under-relaxation can be used over them to promote faster convergence.
------ PIL integer name; group 7 ----------
IMB2.... indicates which whole-field store will be used for the continuity imbalances of phase 2 in response to the command STORE(IMB2). See IMB1 for further information.
IMMERSOL , the method of handling simultaneous radiation and conjugate heat transfer in
complex circumstances.
See PHENC entry: Radiative
Heat Transfer in PHOENICS; section 3
------ PIL integer; default=1; group 6 ----
IMON....index for specifying I location ( in BFC nomenclature ) at which the coordinates:
The finite-volume equations solved by PHOENICS (see PHENC entry) include algebraic formulae for FP, the value of variable F at point P, in terms of the values of F at the nort, south, east, west, high and low neighbouring cells, i.e. FE, FW, FN, FS, FH, and FL.
If these neighbour values of F are those which prevail at the current time step, the "implicit formulation" is said to be in use. This is what is used when N is entered as the 6th argument of SOLUTN; it is the default; and it is recommended for general use.
When Y is entered as the 6th argument, the neighbour values are taken as those which prevailed at the end of the previous time step, the "explicit formulation" is said to be in use. This option may be used to effect computer-time economies when the so-called "Courant criterion" is satisfied, namely u*dt/dx <1, where dt and dx refer to the time and space step sizes and u is the velocity.
One may wish to select for explicit treatment those variables which change much more slowly with time than other variables, again for reasons of economy.
See PHENC entry: schemes
---- PIL integer; default=1; group 25 --- -
INCHCK....element number of F-array, the value of which is checked to be greater than SMCHCK and less than BGCHCK. The number may be obtained by setting DBINDX=T.
Insertion of INCL(file_name , on a single line in a Q1 file, with or without a closing bracket, will load the named file into the instruction stack with the same effect as though the contents of the file resided in the Input-File Library.
If lines containing TALK=... or STOP are present in the file, these lines will be ignored. Q1's can therefore be "swallowed whole".
This feature enables users to use the same set of instructions in many different Q1 files, without having to copy them in.
The so-loaded file can itself contain l( or incl( commands.
(see STEADY)
In general, a phenomenon simulated by PHOENICS will be four-dimensional, the four dimensions being time, and three space dimensions. The latter are called, for ease of reference: north-south; east-west; and high-low. Specifically:
------------------------------------
Ground integer.
INDVAR....is the number of current dependent- or auxiliary- variable number.
----- PIL real flag; value= 23.0; group 13 -
INFLO....is a PATCH type used to specify PATCHes at which only inflow is desired. Thus, where a pressure boundary condition prevails at such a PATCH, cell pressures in excess of the outside pressure do not cause outflow.
---- PIL logical; default=F; group 11 --- -
INIADD....controls whether or not the initial fields which are set by way of FIINIT, PATCH and INIT are additive over intersecting PATCHes.
When INIADD is T, they are added.
When INIADD is F, they are not added, and the
last PATCH overwrites what is implied by FIINIT and any preceding PATCHes.
The CONPOR command unconditionally resets INIADD to F.
It is also set to .FALSE. in EARTH, whenever PRPS is stored and its value is set to a value which is present in the PROPS file; for the addition of such values can have no physical significance.
---- PIL logical; default=F; group 21 --- -
INIFLD....may be set to T if it is desired that the initial fields should be printed. See FIINIT to learn how these are set.
(Stream Menu)------------------------------------- Photon Help ----
[IniPln] specifies the initial seeding plane. All streamlines will be drawn from this plane.
See also: [Set]
When the grid is cylindrical polar, and it is desired to create an initial velocity field which is uniform, the following provisions in the Q1 file will have the desired effect:
INIADD=F
PATCH(INIPOLxx,INIVAL,1,NX,1,NY,1,NZ,1,1)
INIT(INIPOLxx,U1,0.0,GRND)
INIT(INIPOLxx,V1,0.0,GRND)
FIINIT(V1) = absolute velocity in the XY plane
FIINIT(U1) = angle (in radians) between the direction of the velocity and the (angular
)x-axis
------ Command; group 11 --------------
INIT....is a command used for setting PATCH-wise initial conditions. It has four arguments.
Initial values may be inserted, PATCH-wise, by means of the commands PATCH and INIT. In the former, INIVAL must be inserted as the second entry, thus:
PATCH(patch name, INIVAL, first IX, last IX, etc ) .
Then the INIT command follows, for all variables which it is desired to set in this way, as:
INIT(patch name, variable name or index, ZERO, value ) . See the Encyclopaedia entry: INITIAL CONDITIONS.
---- PIL real flag; value= 26.0; group 11 -
INIVAL....is a PATCH type used in group 11 for specifying zones of constant initial values specified for a given-field variable by the 4th argument of INIT.
See INIT for further information.
An INLET object defines an area of fixed mass flow. The mass flow can be specified as:
----- Command; group 13 --------------
This command is used to declare inlets, i.e. fixed-mass-inflow boundaries. Used in conjunction with VALUE it does no more than can be done via PATCH and COVAL, but is slightly more compact and conceptually easier to deal with.
As well as the mass-flow rate per unit area, non-zero values of velocity and scalar quantities convected in by the mass flow can be specified by the VALUE command. See the entry on VALUE for more information.
The syntax is : INLET(NAME,TYPE,IXF,IXL,IYF,IYL,IZF,IZL,ITF,ITL)
NAME is a unique identifier for the INLET, up to 8 characters in length. TYPE can be NORTH,SOUTH,EAST,WEST,HIGH or LOW, and specifies which cell face areas will be used to multiply the mass-flow set. IXF ... ITL specify the limits in space and time over which the mass source is to be active. Thus :
REAL(WIN,RHOIN); WIN=3; RHOIN=1.0
INLET(INL1,LOW,1,NX,1,NY,1,1,1,LSTEP)
VALUE(INL1,P1,RHOIN*WIN) ; VALUE(INL1,W1,WIN)
specifies an INLET extending from IX = 1 to NX, IY = 1 to NY at IZ = 1, active over all time steps, in which mass is entering the LOW faces of the cell at a rate of RHOIN*WIN/unit area.
The function of the command is to generate a PATCH with the NAME and TYPE specified over the set limits. COVALs are also generated for all solved variables, with ONLYMS,0.0 for the COefficient and VALue, except for P1 (and P2 if .NOT.ONEPHS) which has COefficient FIXFLU, VALue 0.0.
See the entries on SOURCE, PATCH, COVAL, TYPE and FIXFLU for further details.
(see INLET)
(see LITXC)
(see RINNER)
(see IURVAL)
------------------------- Input Photon Help ----
[Input Window] is used to type in the coordinates of each point of the geomentry.
(see CLEAR)
The solution of the differential transport equations is sometimes called (numerical) integration of the equations.
(see XULAST)
(see NX)
(see PHINT)
(see Alternative Interpolation Schemes.)
---------------------------------- Photon Help ----
[Intervals] shows the number of intervals if the current CONTOUR element was drawn with isolines.
(see GRDPWR command)
Integer used in GXIFRIC to denote interphase friction coefficient.
Integer used in GXIMAS to denote interphase mass-transfer rate.
INTPOL is a PIL function to perform a linear interpolation in a table read from a file. The format of the command is:
Yvalue = INTPOL(file_name, Xcol, Ycol, Xvalue)
Yvalue is the output of the function. It can be directed into any valid PIL variable or command.
file_name - is the name of the file to be read. If the file is not in the working directory, the full path to the file must be included. Within the file, blank lines are ignored. Lines starting * or # are ignored. Anything after ! is ignored. The file may contain any number of lines and columns, but each line must contain the same number of columns. The first active line must contain character strings defining the names of the columns. Space, comma, semi-colon or tab can be used as separators between columns.
Xcol - is the name of the column to use as X
Ycol - is the name of the column to use as Y
Xvalue - is the value of X at which Y is to be evaluated.
As an example let the file ethglyc.csv contain the values of enthalpy (ENT), specific volume (SPV), kinematic viscosity (ENU), conductivity (CND) and diffusion coefficient (DIF) as functions of temperature (TEM):
TEM, ENT, SPV, ENU, CND, DIF -17.8 , -1238746.805 , 0.000862069 , 0.000115882 , 0.24813444 , 9.46135E-08 4.4 , -1171705.951 , 0.000873362 , 5.85505E-05 , 0.252724 , 9.38042E-08 26.7 , -1104278.562 , 0.000884956 , 1.9263E-05 , 0.256915667 , 9.20403E-08 48.9 , -1037069.369 , 0.000896861 , 6.34036E-06 , 0.259949667 , 9.09873E-08 71.1 , -969776.1961 , 0.000909091 , 3.90773E-06 , 0.261084667 , 8.85781E-08 93.3 , -902399.0434 , 0.000922509 , 2.28581E-06 , 0.260923667 , 8.7108E-08 115.6 , -834633.8417 , 0.000937207 , 1.43921E-06 , 0.259341333 , 8.4257E-08 137.8 , -767088.3508 , 0.000952381 , 9.49333E-07 , 0.255937333 , 8.19981E-08 170 , -668967.72 , 0.00100038 , 6.55049E-07 , 0.2475 , 8.11784E-08 197.5 , -585029.1675 , 0.001025599 , 4.84083E-07 , 0.2366 , 7.60679E-08
Note that the CND column cannot be used as an independent (X) variable, as it passes through a maximum before decreasing again.
To extract the value of dynamic viscosity (kinematic viscosity / specific volume) at 50 deg, one could use:
REAL(EMU,TEMVAL) TEMVAL=50. EMU=INTPOL(ETHGLYC.CSV,TEM,ENU,TEMVAL)/INTPOL(ETHGLYC.CSV,TEM,SPV,TEMVAL)
INTPOL can also be used as an InForm function to be executed at solver run-time, as exemplified in the InForm coding below for insertion in Group 9 of the Q1 file:
save9begin ! use INTPOL to perform linear interpolation in data file ! get temperature from solved enthalpy ! File X-col Y-col X-value (property of tmp1 is intpol(ethglyc.csv,ent, tem, h1)) ! get density as 1/(specific volume) as f(temperature) (property rho1 is 1/intpol(ethglyc.csv,tem,spv,tmp1)) ! get kinematic viscosity as a function of temperature (property enul is intpol(ethglyc.csv,tem,enu,tmp1)) ! get conductivity as function of temperature (property of prndtl(h1) is -intpol(ethglyc.csv,tem,cnd,tmp1)) ! store specific volume and dynamic viscosity for checking (stored of spv is 1./rho1) (stored of emu is rho1*intpol(ethglyc.csv,tem,enu,tmp1)) save9end
Integer used in GXIDIF to denote phase-1 to interface transfer coefficient.
Integer used in GXIDIF to denote phase-2 to interface transfer coefficient.
Integer used in GXIVAL to denote interface value for a first-phase variable.
Integer used in GXIVAL to denote interface value for a second-phase variable.
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IOPTN....holds the value of the PHOENICS option which has been installed, and which governs the capabilities of PHOENICS which may be activated.
>>> See also the Encyclopaedia entry 'OPTIONS'.
The value of IOPTN is "locked" into EARTH at the time of installation, and cannot be changed by the user.
---- PIL integer; default=0; group 14 --- -
IPARAB....specifies the pressure-boundary type for parabolic calculations ( i.e. PARAB=T ).
IPARAB=0 instructs EARTH to deduce the pressure downstream of each z slab, by reference to total mass continuity. This option is for use in flows whose lateral ( i.e. x-wise and y-wise ) boundaries are confined ones ( as in pipes and ducts generally ).
Other options are:
----- PIL integer; default=1; group 23 --- -
IPLTF....first sweep for plots of spot values and residuals.
On restart runs, this should be set to FSWEEP in order to avoid the allocation of a segment of EARTH storage for the information from 1 to FSWEEP-1 which will not be used.
----- PIL integer; default=-1; group 23 -- -
IPLTL...last sweep for plots of spot values, etc. The default of -1 ensures that if the user has not set IPLTL, EARTH will set it to LSWEEP ( or to LITHYD if PARABolic ).
------- PIL integer; group 11 & 19 ------
IPORIA... is used in the specification of porosities that depend, dynamically, upon pressure for cells for which IZ is no greater than IPORIA.
See the help and encyclopaedia entries on POROSI, and GREX3, GXHOL, GXPORA and GXSURF for further information.
--------- PIL integer; group 11 ---------
IPORIB... is used in the initialisation of porosities to simulate different fixed geometries.
See the help and encyclopaedia entries on POROSI, and GREX3 and GXPORI for further information.
------- PIL integer array ----------------- Read only.
Internal storage of information set by OUTPUT command.
The settings of IPRN are based on prime numbers. ISLN(PHI) divisible by 2, 3, 5, 7, 11, 13.
----- PIL integer; default=1; group 23 --- -
IPROF....integer controlling the format of line-printer plots elicited by PATCH(...., PROFIL,....), as follows:
For IPROF greater than 0, the third and fourth PLOT arguments have the following significances:
The number of columns printed horizontally for option IPROF=0 is set by NCOLPF, whereas for IPROF=1, 2 and 3 the dimensions of the diagrams plotted are determined by ABSIZ and ORSIZ.
Index used in GXPRUTIL and elsewhere to indicate which material property is in question.
--------- PIL integer; group 9 ----------
IPRPSA... is used to carry the PRPS index of the heavier fluid in free-surface problems. See the help and encyclopaedia entries on Height of liquid, VOF and Scalar-equation method and GREX3 for further information.
--------- PIL integer; group 9 ----------
IPRPSB... is used to carry the PRPS index of the lighter fluid in free-surface problems. See the help and encyclopaedia entries on Height of liquid , VOF and Scalar-equation method and GREX3 for further information.
--------- PIL integer; group 9 ----------
IPRPSC... is used to carry the PRPS index of the third fluid in three-phase VOF problems. See the help and encyclopaedia entries on VOF and Scalar-equation method and GREX3 for further information.
Method used in PHOENICS to solve the system of algebraic equations for two-phase flows. IPSA stands for Inter-Phase Slip Algorithm.
PIL Integer; group 13 ----------
IROTAA... is a switch used to activate a source term for velocities in cases with rotating coordinate systems.
See the encyclopaedia entry for ROTATIONAL Momentum Sources.
Ground integer.
IRUN....is the current run number.
an integer set by EARTH, together with IGR, to dictate which section of GROUND, GREX3, etc is to be entered.
See PHENC: GROUND
PIL Integer; default=1; group 8 ---------
Denotes the first sweep on which higher-order schemes are active. For transient cases and restart runs, the schemes are always active.
See the item Schemes for Convection Discretization for details of the schemes available.
------ PIL integer; default=0; group 19 --- -
ISG1, ISG2, ISG3, etc were originally provided as spare integer variables which could be ascribed values in (group 19 of) the Q1 file, and then transmitted to the solver module, EARTH, via the eardat file.
They reside in the file which is "included" in both SATELLITE and GROUND Fortran, namely: satgrd.
The common block /ISG/, which is dimensioned in main.for has 100 elements; but, as will be seen, many of them have other names than ISGx.
These variables have, in the course of time, become PIL variables used for particular purposes, as can be seen by inspecting the common block /ISG/ of satgrd.
Thus ISG20 has been replaced by MAXSEC, which is used in the "time-out" feature.
Further, ISG21 (which has not yet been given a PIL equivalent) sets the minimum number of sweeps which must be performed, regardless of the values to which the residuals have fallen (for versions 3.5.1 and beyond only).
Additionally (for version 3.6 and beyond):
--------- PIL integer; group 13 ---------
ISKINA... is used to carry the number of iterations to be taken in the calculation of the dimensionless skin-friction factor for turbulent wall-functions.
See the help and encyclopaedia entries on TURBUL and WALL, and GXWFUN for further information.
--------- PIL integer; group 13 ---------
ISKINB... is a switch used to activate different formulae for the skin-friction factor for turbulent wall-functions.
See the help and encyclopaedia entries on TURBUL and WALL, and GXWFUN for further information.
------- PIL integer array -----------------
Read only.
Internal storage of information set by SOLUTN command.
(View Menu) ------------------------------------ Photon Help ----
Reset the view direction to (1, 1, 1).
This sets the iteration frequency with which the user-defined block corrections are performed. The default of 0 means that no block corrections are made. See BLOK for further details.
----- PIL integer; default=-1; group 8 --- -
ISOLX....parameter controlling the iteration frequency of x-wise block-adjustments in the linear equation solver. ISOLY and ISOLZ activate similar adjustments in the y- and z-directions. The adjustments are performed for any variable not solved point-by- point.
The default setting of -1 means that the adjustments will be performed only on the first iteration of each sweep. A setting of -2 would indicate only the first 2 iterations, and so on. A value of zero means that the adjustment is de-activated. This may prove advantageous when the domain is multiply connected due to the presence of blockage barriers.
It is frequently advantageous to set the ISOL parameter for the main flow direction to be > 0, as this can speed convergence. A value of 1 means block-adjustment every iteration, 2 means every second iteration, and so on.
If LITER(phi) is negative, the block-adjustments applied will be displayed at the screen.
----- PIL integer; default=-1; group 8 --- -
ISOLY....see ISOLX
----- PIL integer; default=-1; group 8 --- -
ISOLZ....see ISOLX
----- PIL integer; default=-1; group 8 --- -
ISRFTA....parameter controlling which formulation is used for the surface tension coefficient.
---- PIL integer; default=1; group 25 --- -
ISTDB1....first time step at which debug printed.
---- PIL integer; default=1; group 25 --- -
ISTDB2....last time step at which debug printed.
-------------------------------------
Ground integer.
ISTEP....is the time-step number.
---- PIL integer; default=1; group 23 --- -
ISTPRF....first time step at which fields are printed.
---- PIL integer; default=10000; group 23 -
ISTPRL....last time step at which fields are printed.
---- PIL integer; default=0; group 19 -
ISURFA....denotes which free surface model to use:
| ISURFA | Method |
| 0 | SEM |
| 1 | VOF - CICSAM |
| 2 | VOF - HRIC |
| 3 | VOF - MHRIC |
| 4 | VOF - STACS |
| 5 | VOF - THINC |
See FREE-SURFACE-FLOW simulation in PHOENICS for more information.
----- PIL integer; default=1; group 15 --- -
ISWC1....first sweep through field for which solution for variables with indices greater than 13 takes place, ie. H1, H2, C1, C2, C3,.....C35.
Economy may be effected by setting this greater than 1, so that the velocity field has time to settle before time is spent on scalar variables.
---- PIL integer; default=1; group 25 --- -
ISWDB1....first sweep at which debug printed.
---- PIL integer; default=1; group 25 --- -
ISWDB2....last sweep at which debug printed.
------------------------------------- Ground integer.
ISWEEP....is the current sweep number.
---- PIL integer; default=1; group 23 --- -
ISWPRF....first sweep at which fields are printed.
---- PIL integer; default=10; group 23 -- -
ISWPRL....last sweep at which fields are printed.
----- PIL integer; default=1; group 15 --- -
ISWR1...is the first sweep on which the equations for the volume fractions R1 and R2 are solved. It can sometimes be helpful for convergence to delay the solution of the volume-fraction fields until the sweep at which a reasonable velocity distribution is obtained, for example. See ISWR2.
----- PIL integer; default=10000; group 15 -
ISWR2....is the last sweep on which the volume fractions R1 and R2 are solved. See ISWR1.
----- PIL integer; default=3; group 23 --- -
ITABL....controls the tabulation and plotting of spot-values and residuals, the print-out of which is activated by the last two arguments of OUTPUT. The significance of its value is as follows:
ITABL=0....no plots and no tables;
ITABL=1....plots but no tables;
ITABL=2....tables but no plots; and
ITABL=3....tables and plots.
(see ISOLBK)
(see ISOLX)
(also see Sweeps)
(see LITER)
----- PIL integer; default=1; group 15 --- -
ITHC1....is the first outer iteration over slab at which solution for variables with indices greater than 11 takes place, ie. KE, EP, H1, H2, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10. Economy can be effected by setting this greater than 1, so that the velocity field has time to settle before time is spent on scalar variables.
---- PIL integer; default=1; group 25 --- -
ITHDB1....first hydrodynamic iteration at which debug is printed. This is used in PARABolic calculations.
---- PIL integer; default=1; group 25 --- -
ITHDB2....last hydrodynamic iteration at which debug is printed. This is used in PARABolic calculations.
-------------------------------------
Ground integer.
ITHYD....is the current iteration number at the current z-slab.
See LITHYD.
---------- PIL integer; group 13 ---------
ITIMA... is used to specify the period in terms of the number of time-steps of a periodic source.
See the help and encyclopaedia entries on ???, and GXTIM for further information.
---------- PIL integer; group 13 ---------
ITIMB... is used to specify the first time-step at which a periodic source should be applied. See the help and encyclopaedia entries on ???, and GXTIM for further information.
---------- PIL integer; group 13 ---------
ITIMC... is used to specify the last time-step at which a periodic source should be applied.
See the help and encyclopaedia entrie on ???, and GXTIM for further information.
---- PIL integer; default=0; group 11 --- -
IURINI....is used to initialize the U1 velocity in a cylindrical polar coordinate system, to represent:
FIINIT(U1) and FIINIT(U2) are set to one of the above constants, and this results in EARTH initializing the velocity fields to contant/radius or constant*radius according to IURINI = 1 or -1.
---- PIL integer; default=0; group 21 --- -
IURPRN....provides options for the print-out of the velocity U1 and U2 in cylindrical-polar coordinates ( CARTES=F ). These options are:
See IURINI and IRVAL for further information.
---- PIL integer; default=0; group 13 --- -
When U1 or U2 are solved for, and CARTES=F, the 'value' argument of COVAL, INIT, PLOT and WALL is interpreted by EARTH as
Un * RADIUS ** IURVAL
The argument is thus:
Un, i.e. velocity, when IURVAL has its default value;
Un / RADIUS, i.e. angular velocity, when IURVAL = -1; or
Un * RADIUS, i.e. angular momentum, when IURVAL = 1
It is especially useful when the boundary conditions are of solid- body rotations ( IURVAL = -1 ) or constant angular momentum ( IURVAL = 1 ).
The value of IURVAL affects all patches. If the angular-velocity or angular momentum interpretation is to be applied only to selected patches, IURVAL should be left at its default value, and the patch names should have UMR or UDR as the 6th, 7th and 8th characters, according to whether U multiplied by R or U divided by R is required.
For example, the commands,
PATCH(ROTATUDR,LOW,1,NX,1,NY/2,1,1,1,1)
COVAL(ROTATUDR,P1,FIXFLU,1.0)
COVAL(ROTATUDR,U1,ONLYMS,20.0)
set a mass inflow of 1 kg/s rotating as a solid body at 20 radians per second at the inner
half of the boundary at IZ=1.
The commands,
PATCH(SWIRLUMR,LOW,1,NX,NY/2+1,NY,1,1,1,1)
COVAL(SWIRLUMR,P1,FIXFLU,2.0)
COVAL(SWIRLUMR,U1,ONLYMS,10.0)
set a mass inflow of 2 kg/s rotating with a constant angular momentum of 10 ( m**2/s ) at
the outer half of the boundary at IZ=1.
See IURINI and IURPRN for further information.
-------- PIL integer; default=0; group 7 -
This identifies the variable selected for user-defined block corrections, eg IVARBK=14 would select the 1st phase enthalpy for additional block-corrections. The index number associated with each variable can be found in the NAME entry. IVARBK=-1 selects all solved-for variables.
See BLOK for further details.
Integer used in GXVIRMS to denote virtual-mass coefficient.
-----------------------------------------
Integer; default=1.
IX....ranges from 1 to NX, denoting the grid-point location in the x-direction of PHOENICS, but not necessarily in the cartesian-x direction for BFC=T. In the latter IX=I-1 (see BODY-F for the indicial nomenclature in use in body-fitted coordinates).
(Grid, Contour, Vector and Stream Menu)---------------------------------------- -
Ground integer.
IXF....is the west extent of the current patch within the slab.
(Grid, Contour, Vector and Stream Menu)---------------------------------------- Photon Help ----
[IXF] is the lower limit of the current block region in X direction.
(Grid, Contour, Vector and Stream Menu)---------------------------------------- -
Ground integer.
IXL....is the east extent of the current patch within the slab.
(Grid, Contour, Vector and Stream Menu)---------------------------------------- Photon Help ----
[IXL] is the upper limit of the current block region in X direction.
IXMON....IX-value of spot-value location.
The print-out of fields of variables is bulky: it is best therefore activated infrequently.
However, EARTH can also provide compact print-out, which can be activated every sweep or every few sweeps; this allows the user to monitor the progress of the iterative solution.
This monitor print-out comprises the values of all variables for which Y has been entered in the sixth argument of OUTPUT, for a single grid location identified by the indices IXMON, IYMON and IZMON.
The choice of spot-value location is thus at the user's discretion; values of IXMON, IYMON and IZMON would generally be chosen to lie within a region of the flow which is of particular interest, either from the engineering standpoint, or because convergence difficulties are expected in that region.
IXPRF....is the first IX column printed in the tabulation of the fields selected by OUTPUT.
IXPRL....is the last IX column printed in the tabulation of the fields selected by OUTPUT.
-----------------------------------------
Integer; default=1.
IY....ranges from 1 to NY, denoting the grid-point location in the y-direction of PHOENICS, but not necessarily in the cartesian-y direction for BFC=T. In the latter IY=J-1 (see BODY-F for the indicial nomenclature in use in body-fitted coordinates).
(Grid, Contour, Vector and Stream Menu)----------------------------------------
Ground integer.
IYF....is the south extent of the current patch within the slab.
(Grid, Contour, Vector and Stream Menu)---------------------------------------- Photon Help ----
[IYF] is the lower limit of the current block region in Y direction.
(Grid, Contour, Vector and Stream Menu)---------------------------------------- -
Ground integer.
IYL....is the north extent of the current patch within the slab.
(Grid, Contour, Vector and Stream Menu)---------------------------------------- Photon Help ----
[IYL] is the upper limit of the current block region in Y direction.
----- PIL integer; default=1; group 22 --- -
IYMON....IY-value of spot-value location. See IXMON.
----- PIL integer; default=1; group 23 --- -
IYPRF....is the first IY column printed in the tabulation of the fields selected by OUTPUT.
----- PIL integer; default=10000; group 23 -
IYPRL....is the last IY column printed in the tabulation of the fields selected by OUTPUT.
-----------------------------------------
Integer; default=1.
IZ....ranges from 1 to NZ, denoting the grid-point location in the z-direction of PHOENICS, but not necessarily in the cartesian-z direction for BFC=T. In the latter IZ=K-1 (see BODY-F for the indicial nomenclature in use in body-fitted coordinates).
----- PIL integer; default=1; group 25 --- -
IZDB1....first IZ slab at which debug printed.
----- PIL integer; default=1; group 25 --- -
IZDB2....last IZ slab at which debug printed.
(Grid, Contour, Vector and Stream Menu)---------------------------------------- Photon Help ----
[IZF] is the lower limit of the current block region in Z direction.
(Grid, Contour, Vector and Stream Menu)---------------------------------------- Photon Help ----
[IZL] is the lower limit of the current block region in Z direction.
....IZ-value of spot-value location. See IXMON.
For PARAB = T, the graphical monitor is activated only for IZ values which are whole-number multiples of IZMON
Negative values of IZMON may also be accepted, These have the effect of replacing the displays of "spot values" and residuals on the graphical-monitor screen by those of the whole-domain maximum and minimum values of each variable.
The spot values printed in the result file remain those pertaining to the IZ-slab corresponding to the absolute (ie sign-free) value of IZMON.
----- PIL integer; default=1; group 23 --- -
IZPRF....is the first IZ column printed in the tabulation of the fields selected by OUTPUT.
----- PIL integer; default=10000; group 23 -
IZPRL....is the last IZ column printed in the tabulation of the fields selected by OUTPUT.
------------------------------------- Ground integer.
IZSTEP....is the current z-slab.
------ PIL integer; default=0; group 19 --- -
IZW1....is the iz location of the last slab in part one of an n-part moving grid. See ZMOVE, and the piston-in-cylinder example in subroutine GXPISTON called from section 1 of group 19 of GREX.