Loading...
Searching...
No Matches
flashmodel.hh File Reference

A compositional multi-phase model based on flash-calculations. More...

`#include <opm/material/constraintsolvers/NcpFlash.hpp>`
`#include <opm/material/densead/Math.hpp>`
`#include <opm/material/fluidmatrixinteractions/MaterialTraits.hpp>`
`#include <opm/material/fluidmatrixinteractions/NullMaterial.hpp>`
`#include <opm/models/common/energymodule.hh>`
`#include <opm/models/common/multiphasebasemodel.hh>`
`#include <opm/models/flash/flashboundaryratevector.hh>`
`#include <opm/models/flash/flashextensivequantities.hh>`
`#include <opm/models/flash/flashindices.hh>`
`#include <opm/models/flash/flashintensivequantities.hh>`
`#include <opm/models/flash/flashlocalresidual.hh>`
`#include <opm/models/flash/flashparameters.hh>`
`#include <opm/models/flash/flashprimaryvariables.hh>`
`#include <opm/models/flash/flashproperties.hh>`
`#include <opm/models/flash/flashratevector.hh>`
`#include <opm/models/io/vtkcompositionmodule.hpp>`
`#include <opm/models/io/vtkdiffusionmodule.hpp>`
`#include <opm/models/io/vtkenergymodule.hpp>`
`#include <cassert>`
`#include <memory>`
`#include <sstream>`
`#include <string>`
`#include <tuple>`

Go to the source code of this file.

## Classes

struct | Opm::Properties::TTag::FlashModel
| The type tag for the isothermal single phase problems. More...
struct | Opm::Properties::LocalResidual< TypeTag, TTag::FlashModel >
| Use the FlashLocalResidual function for the flash model. More...
struct | Opm::Properties::FlashSolver< TypeTag, TTag::FlashModel >
| Use the NCP flash solver by default. More...
struct | Opm::Properties::Model< TypeTag, TTag::FlashModel >
| the Model property More...
struct | Opm::Properties::PrimaryVariables< TypeTag, TTag::FlashModel >
| the PrimaryVariables property More...
struct | Opm::Properties::RateVector< TypeTag, TTag::FlashModel >
| the RateVector property More...
struct | Opm::Properties::BoundaryRateVector< TypeTag, TTag::FlashModel >
| the BoundaryRateVector property More...
struct | Opm::Properties::IntensiveQuantities< TypeTag, TTag::FlashModel >
| the IntensiveQuantities property More...
struct | Opm::Properties::ExtensiveQuantities< TypeTag, TTag::FlashModel >
| the ExtensiveQuantities property More...
struct | Opm::Properties::Indices< TypeTag, TTag::FlashModel >
| The indices required by the flash-baseed isothermal compositional model. More...
struct | Opm::Properties::EnableDiffusion< TypeTag, TTag::FlashModel >
struct | Opm::Properties::EnableEnergy< TypeTag, TTag::FlashModel >
| Disable the energy equation by default. More...
class | Opm::FlashModel< TypeTag >
| A compositional multi-phase model based on flash-calculations. More...

## Namespaces

namespace | Opm
| This file contains a set of helper functions used by VFPProd / VFPInj.
namespace | Opm::Properties::TTag
| The generic type tag for problems using the immiscible multi-phase model.

## Detailed Description

A compositional multi-phase model based on flash-calculations.

This model assumes a flow of fluid phases , each of which is assumed to be a mixture chemical species (denoted by the upper index ).

By default, the standard multi-phase Darcy approach is used to determine the velocity, i.e.

although the actual approach which is used can be specified via the `FluxModule` property. For example, the velocity model can by changed to the Forchheimer approach by

template<class TypeTag>
struct FluxModule<TypeTag, TTag::MyProblemTypeTag> { using type = Opm::ForchheimerFluxModule<TypeTag>; };
Opm::ForchheimerFluxModule
Specifies a flux module which uses the Forchheimer relation.
Definition forchheimerfluxmodule.hh:66

The core of the model is the conservation mass of each component by means of the equation

To determine the quanties that occur in the equations above, this model uses flash calculations. A flash solver starts with the total mass or molar mass per volume for each component and, calculates the compositions, saturations and pressures of all phases at a given temperature. For this the flash solver has to use some model assumptions internally. (Often these are the same primary variable switching or NCP assumptions as used by the other fully implicit compositional multi-phase models provided by eWoms.)

Using flash calculations for the flow model has some disadvantages:

- The accuracy of the flash solver needs to be sufficient to calculate the parital derivatives using numerical differentiation which are required for the Newton scheme.
- Flash calculations tend to be quite computationally expensive and are often numerically unstable.

It is thus adviced to increase the target tolerance of the Newton scheme or a to use type for scalar values which exhibits higher precision than the standard `double` (e.g. `quad`) if this model ought to be used.

The model uses the following primary variables:

- The total molar concentration of each component:
- The absolute temperature $T$ in Kelvins if the energy equation enabled.

This model assumes a flow of fluid phases , each of which is assumed to be a mixture chemical species (denoted by the upper index ).

By default, the standard multi-phase Darcy approach is used to determine the velocity, i.e.

although the actual approach which is used can be specified via the `FluxModule` property. For example, the velocity model can by changed to the Forchheimer approach by

template<class TypeTag>
struct FluxModule<TypeTag, TTag::MyProblemTypeTag> { using type = Opm::ForchheimerFluxModule<TypeTag>; };

The core of the model is the conservation mass of each component by means of the equation

To determine the quanties that occur in the equations above, this model uses flash calculations. A flash solver starts with the total mass or molar mass per volume for each component and, calculates the compositions, saturation and pressures of all phases at a given temperature. For this the flash solver has to use some model assumptions internally. Here a constant pressure, constant temperature, two-phase flash calculation method is used.