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unitConversion: Unit conversions on all input parameters

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The majority of input parameters now support automatic unit conversion.
Units are specified within square brackets, either before or after the
value. Primitive parameters (e.g., scalars, vectors, tensors, ...),
dimensioned types, fields, Function1-s and Function2-s all support unit
conversion in this way.

Unit conversion occurs on input only. OpenFOAM writes out all fields and
parameters in standard units. It is recommended to use '.orig' files in
the 0 directory to preserve user-readable input if those files are being
modified by pre-processing applications (e.g., setFields).

For example, to specify a volumetric flow rate inlet boundary in litres
per second [l/s], rather than metres-cubed per second [m^3/s], in 0/U:

    boundaryField
    {
        inlet
        {
            type            flowRateInletVelocity;
            volumetricFlowRate 0.1 [l/s];
            value           $internalField;
        }

        ...
    }

Or, to specify the pressure field in bar, in 0/p:

    internalField   uniform 1 [bar];

Or, to convert the parameters of an Arrhenius reaction rate from a
cm-mol-kcal unit system, in constant/chemistryProperties:

    reactions
    {
        methaneReaction
        {
            type    irreversibleArrhenius;
            reaction "CH4^0.2 + 2O2^1.3 = CO2 + 2H2O";
            A       6.7e12 [(mol/cm^3)^-0.5/s];
            beta    0;
            Ea      48.4 [kcal/mol];
        }
    }

Or, to define a time-varying outlet pressure using a CSV file in which
the pressure column is in mega-pascals [MPa], in 0/p:

    boundaryField
    {
        outlet
        {
            type            uniformFixedValue;
            value
            {
                type            table;
                format          csv;
                nHeaderLine     1;
                units           ([s] [MPa]); // <-- new units entry
                columns         (0 1);
                mergeSeparators no;
                file            "data/pressure.csv";
                outOfBounds     clamp;
                interpolationScheme linear;
            }
        }

        ...
    }

(Note also that a new 'columns' entry replaces the old 'refColumn' and
'componentColumns'. This is is considered to be more intuitive, and has
a consistent syntax with the new 'units' entry. 'columns' and
'componentColumns' have been retained for backwards compatibility and
will continue to work for the time being.)

Unit definitions can be added in the global or case controlDict files.
See UnitConversions in $WM_PROJECT_DIR/etc/controlDict for examples.
Currently available units include:

    Standard: kg m s K kmol A Cd

     Derived: Hz N Pa J W g um mm cm km l ml us ms min hr mol
              rpm bar atm kPa MPa cal kcal cSt cP % rad rot deg

A user-time unit is also provided if user-time is in operation. This
allows it to be specified locally whether a parameter relates to
real-time or to user-time. For example, to define a mass source that
ramps up from a given engine-time (in crank-angle-degrees [CAD]) over a
duration in real-time, in constant/fvModels:

    massSource1
    {
        type        massSource;
        points      ((1 2 3));
        massFlowRate
        {
            type        scale;
            scale       linearRamp;
            start       20 [CAD];
            duration    50 [ms];
            value       0.1 [g/s];
        }
    }

Specified units will be checked against the parameter's dimensions where
possible, and an error generated if they are not consistent. For the
dimensions to be available for this check, the code requires
modification, and work propagating this change across OpenFOAM is
ongoing. Unit conversions are still possible without these changes, but
the validity of such conversions will not be checked.

Units are no longer permitted in 'dimensions' entries in field files.
These 'dimensions' entries can now, instead, take the names of
dimensions. The names of the available dimensions are:

    Standard: mass length time temperature
              moles current luminousIntensity

     Derived: area volume rate velocity momentum acceleration density
              force energy power pressure kinematicPressure
              compressibility gasConstant specificHeatCapacity
              kinematicViscosity dynamicViscosity thermalConductivity
              volumetricFlux massFlux

So, for example, a 0/epsilon file might specify the dimensions as
follows:

    dimensions      [energy/mass/time];

And a 0/alphat file might have:

    dimensions      [thermalConductivity/specificHeatCapacity];

*** Development Notes ***

A unit conversion can construct trivially from a dimension set,
resulting in a "standard" unit with a conversion factor of one. This
means the functions which perform unit conversion on read can be
provided dimension sets or unit conversion objects interchangeably.

A basic `dict.lookup<vector>("Umean")` call will do unit conversion, but
it does not know the parameter's dimensions, so it cannot check the
validity of the supplied units. A corresponding lookup function has been
added in which the dimensions or units can be provided; in this case the
corresponding call would be `dict.lookup<vector>("Umean", dimVelocity)`.
This function enables additional checking and should be used wherever
possible.

Function1-s and Function2-s have had their constructors and selectors
changed so that dimensions/units must be specified by calling code. In
the case of Function1, two unit arguments must be given; one for the
x-axis and one for the value-axis. For Function2-s, three must be
provided.

In some cases, it is desirable (or at least established practice), that
a given non-standard unit be used in the absence of specific
user-defined units. Commonly this includes reading angles in degrees
(rather than radians) and reading times in user-time (rather than
real-time). The primitive lookup functions and Function1 and Function2
selectors both support specifying a non-standard default unit. For
example, `theta_ = dict.lookup<scalar>("theta", unitDegrees)` will read
an angle in degrees by default. If this is done within a model which
also supports writing then the write call must be modified accordingly
so that the data is also written out in degrees. Overloads of writeEntry
have been created for this purpose. In this case, the angle theta should
be written out with `writeEntry(os, "theta", unitDegrees, theta_)`.
Function1-s and Function2-s behave similarly, but with greater numbers
of dimensions/units arguments as before.

The non-standard user-time unit can be accessed by a `userUnits()`
method that has been added to Time. Use of this user-time unit in the
construction of Function1-s should prevent the need for explicit
user-time conversion in boundary conditions and sub-models and similar.

Some models might contain non-typed stream-based lookups of the form
`dict.lookup("p0") >> p0_` (e.g., in a re-read method), or
`Umean_(dict.lookup("Umean"))` (e.g., in an initialiser list). These
calls cannot facilitate unit conversion and are therefore discouraged.
They should be replaced with
`p0_ = dict.lookup<scalar>("p0", dimPressure)` and
`Umean_(dict.lookup<vector>("Umean", dimVelocity))` and similar whenever
they are found.
This commit is contained in:
Will Bainbridge
2024-04-19 11:44:41 +01:00
parent d21e75ac74
commit 476bb42b04
626 changed files with 8274 additions and 4300 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
tutorials/multiRegion/CHT/reverseBurner/0/gas/G
View File

@ -14,7 +14,7 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 1 0 -3 0 0 0 0 ];
dimensions [mass/time^3];
internalField uniform 0;

4
tutorials/multiRegion/CHT/reverseBurner/0/gas/T
View File

@ -14,7 +14,7 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 0 0 0 1 0 0 0 ];
dimensions [temperature];
internalField uniform 300;
@ -27,14 +27,12 @@ boundaryField
type fixedValue;
value $internalField;
}
outlet
{
type inletOutlet;
value $internalField;
inletValue $internalField;
}
gas_to_solid
{
type coupledTemperature;

2
tutorials/multiRegion/CHT/reverseBurner/0/gas/U
View File

@ -14,7 +14,7 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 0 1 -1 0 0 0 0 ];
dimensions [velocity];
internalField uniform (0 0 0);

2
tutorials/multiRegion/CHT/reverseBurner/0/gas/alphat
View File

@ -14,7 +14,7 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [1 -1 -1 0 0 0 0];
dimensions [thermalConductivity/specificHeatCapacity];
internalField uniform 0;

2
tutorials/multiRegion/CHT/reverseBurner/0/gas/epsilon
View File

@ -14,7 +14,7 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 0 2 -3 0 0 0 0 ];
dimensions [energy/mass/time];
internalField uniform 3.60203e-06;

2
tutorials/multiRegion/CHT/reverseBurner/0/gas/k
View File

@ -14,7 +14,7 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 0 2 -2 0 0 0 0 ];
dimensions [energy/mass];
internalField uniform 0.00016875;

4
tutorials/multiRegion/CHT/reverseBurner/0/gas/nut
View File

@ -10,11 +10,11 @@ FoamFile
format ascii;
class volScalarField;
location "0/gas";
object nutt;
object nut;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 2 -1 0 0 0 0];
dimensions [kinematicViscosity];
internalField uniform 0;

4
tutorials/multiRegion/CHT/reverseBurner/0/gas/p
View File

@ -14,9 +14,9 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 1 -1 -2 0 0 0 0 ];
dimensions [pressure];
internalField uniform 1e6;
internalField uniform 10 [bar];
boundaryField
{

2
tutorials/multiRegion/CHT/reverseBurner/0/gas/p_rgh
View File

@ -14,7 +14,7 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 1 -1 -2 0 0 0 0 ];
dimensions [pressure];
internalField uniform 0;

5
tutorials/multiRegion/CHT/reverseBurner/0/solid/T
View File

@ -14,7 +14,7 @@ FoamFile
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 0 0 0 1 0 0 0 ];
dimensions [temperature];
internalField uniform 300;
@ -25,11 +25,10 @@ boundaryField
external
{
type externalTemperature;
h uniform 1e3;
h 1e3 [W/m^2/K];
Ta $internalField;
value $internalField;
}
solid_to_gas
{
type coupledTemperature;

3
tutorials/multiRegion/CHT/reverseBurner/constant/gas/pRef
View File

@ -15,6 +15,7 @@ FoamFile
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [1 -1 -2 0 0 0 0];
value 1e6;
value 10 [bar];
// ************************************************************************* //

115
tutorials/multiRegion/CHT/reverseBurner/constant/gas/physicalProperties
View File

@ -25,8 +25,121 @@ thermoType
energy sensibleEnthalpy;
}
species
(
O2
H2O
CH4
CO2
N2
);
defaultSpecie N2;
#include "thermo.compressibleGas"
O2
{
specie
{
molWeight 31.9988;
}
thermodynamics
{
Tlow 200;
Thigh 5000;
Tcommon 1000;
highCpCoeffs ( 3.69758 0.00061352 -1.25884e-07 1.77528e-11 -1.13644e-15 -1233.93 3.18917 );
lowCpCoeffs ( 3.21294 0.00112749 -5.75615e-07 1.31388e-09 -8.76855e-13 -1005.25 6.03474 );
}
transport
{
As 1.753e-6;
Ts 139;
}
}
H2O
{
specie
{
molWeight 18.0153;
}
thermodynamics
{
Tlow 200;
Thigh 5000;
Tcommon 1000;
highCpCoeffs ( 2.67215 0.00305629 -8.73026e-07 1.201e-10 -6.39162e-15 -29899.2 6.86282 );
lowCpCoeffs ( 3.38684 0.00347498 -6.3547e-06 6.96858e-09 -2.50659e-12 -30208.1 2.59023 );
}
transport
{
As 2.978e-7;
Ts 1064;
}
}
CH4
{
specie
{
molWeight 16.0428;
}
thermodynamics
{
Tlow 200;
Thigh 6000;
Tcommon 1000;
highCpCoeffs ( 1.63543 0.0100844 -3.36924e-06 5.34973e-10 -3.15528e-14 -10005.6 9.9937 );
lowCpCoeffs ( 5.14988 -0.013671 4.91801e-05 -4.84744e-08 1.66694e-11 -10246.6 -4.64132 );
}
transport
{
As 1.0194e-06;
Ts 171.06;
}
}
CO2
{
specie
{
molWeight 44.01;
}
thermodynamics
{
Tlow 200;
Thigh 5000;
Tcommon 1000;
highCpCoeffs ( 4.45362 0.00314017 -1.27841e-06 2.394e-10 -1.66903e-14 -48967 -0.955396 );
lowCpCoeffs ( 2.27572 0.00992207 -1.04091e-05 6.86669e-09 -2.11728e-12 -48373.1 10.1885 );
}
transport
{
As 1.503e-6;
Ts 222;
}
}
N2
{
specie
{
molWeight 28.0134;
}
thermodynamics
{
Tlow 200;
Thigh 5000;
Tcommon 1000;
highCpCoeffs ( 2.92664 0.00148798 -5.68476e-07 1.0097e-10 -6.75335e-15 -922.798 5.98053 );
lowCpCoeffs ( 3.29868 0.00140824 -3.96322e-06 5.64152e-09 -2.44486e-12 -1020.9 3.95037 );
}
transport
{
As 1.401e-6;
Ts 107;
}
}
// ************************************************************************* //

12
tutorials/multiRegion/CHT/reverseBurner/constant/gas/reactions
View File

@ -12,10 +12,6 @@ Reference:
Combustion science and technology, 27(1-2), 31-43.
Notes:
The reference gives parameters in a unit system of cm-sec-mole-kcal-Kelvin,
whilst OpenFOAM uses m-sec-kmol-J-Kelvin, both the pre-exponential factors
and the activation temperature/energy require unit conversion.
The mechanism used is set 3 from table 2. This should be the most accurate
single-step methane mechanism without any negative exponents. Set 2 is not
usable because the negative exponent on the methane concentration causes
@ -27,11 +23,11 @@ reactions
{
methaneReaction
{
type irreversibleArrhenius;
type irreversibleArrhenius;
reaction "CH4^0.2 + 2O2^1.3 = CO2 + 2H2O";
A 2.11873e+11;
beta 0;
Ta 24357;
A 6.7e12 [(mol/cm^3)^-0.5/s];
beta 0;
Ea 48.4 [kcal/mol];
}
}

124
tutorials/multiRegion/CHT/reverseBurner/constant/gas/thermo.compressibleGas
View File

@ -1,124 +0,0 @@
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: dev
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
species
(
O2
H2O
CH4
CO2
N2
);
O2
{
specie
{
molWeight 31.9988;
}
thermodynamics
{
Tlow 200;
Thigh 5000;
Tcommon 1000;
highCpCoeffs ( 3.69758 0.00061352 -1.25884e-07 1.77528e-11 -1.13644e-15 -1233.93 3.18917 );
lowCpCoeffs ( 3.21294 0.00112749 -5.75615e-07 1.31388e-09 -8.76855e-13 -1005.25 6.03474 );
}
transport
{
As 1.753e-6;
Ts 139;
}
}
H2O
{
specie
{
molWeight 18.0153;
}
thermodynamics
{
Tlow 200;
Thigh 5000;
Tcommon 1000;
highCpCoeffs ( 2.67215 0.00305629 -8.73026e-07 1.201e-10 -6.39162e-15 -29899.2 6.86282 );
lowCpCoeffs ( 3.38684 0.00347498 -6.3547e-06 6.96858e-09 -2.50659e-12 -30208.1 2.59023 );
}
transport
{
As 2.978e-7;
Ts 1064;
}
}
CH4
{
specie
{
molWeight 16.0428;
}
thermodynamics
{
Tlow 200;
Thigh 6000;
Tcommon 1000;
highCpCoeffs ( 1.63543 0.0100844 -3.36924e-06 5.34973e-10 -3.15528e-14 -10005.6 9.9937 );
lowCpCoeffs ( 5.14988 -0.013671 4.91801e-05 -4.84744e-08 1.66694e-11 -10246.6 -4.64132 );
}
transport
{
As 1.0194e-06;
Ts 171.06;
}
}
CO2
{
specie
{
molWeight 44.01;
}
thermodynamics
{
Tlow 200;
Thigh 5000;
Tcommon 1000;
highCpCoeffs ( 4.45362 0.00314017 -1.27841e-06 2.394e-10 -1.66903e-14 -48967 -0.955396 );
lowCpCoeffs ( 2.27572 0.00992207 -1.04091e-05 6.86669e-09 -2.11728e-12 -48373.1 10.1885 );
}
transport
{
As 1.503e-6;
Ts 222;
}
}
N2
{
specie
{
molWeight 28.0134;
}
thermodynamics
{
Tlow 200;
Thigh 5000;
Tcommon 1000;
highCpCoeffs ( 2.92664 0.00148798 -5.68476e-07 1.0097e-10 -6.75335e-15 -922.798 5.98053 );
lowCpCoeffs ( 3.29868 0.00140824 -3.96322e-06 5.64152e-09 -2.44486e-12 -1020.9 3.95037 );
}
transport
{
As 1.401e-6;
Ts 107;
}
}
// ************************************************************************* //

4
tutorials/multiRegion/CHT/reverseBurner/system/gas/fvSolution
View File

@ -52,8 +52,8 @@ solvers
G
{
solver GAMG;
smoother GaussSeidel;
solver PCG;
preconditioner DIC;
tolerance 1e-5;
relTol 0.1;
}

22
tutorials/multiRegion/CHT/wallBoiling/constant/fluid/phaseProperties
View File

@ -130,22 +130,18 @@ saturationTemperature
{
gas_liquid
{
type function1;
type function1;
function scale;
xScale 1e-6;
scale 1;
value
function
{
type tableFile;
format csv;
nHeaderLine 1;
refColumn 1;
componentColumns (0);
mergeSeparators no;
type table;
format csv;
nHeaderLine 1;
units ([MPa] [K]);
columns (1 0);
mergeSeparators no;
file "$FOAM_TUTORIALS/resources/thermoData/wallBoiling-saturation.csv";
outOfBounds clamp;
outOfBounds clamp;
interpolationScheme linear;
}
}