The Dynamic Adaptive Chemistry (DAC) method [1] simplify the chemistry using the matrix rAB defined by (DRGEP algorithm [2]) More...

Inheritance diagram for DAC< ThermoType >:

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Collaboration diagram for DAC< ThermoType >:

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Public Member Functions
	TypeName ("DAC")
	Runtime type information. More...

	DAC (const IOdictionary &dict, chemistryModel< ThermoType > &chemistry)
	Construct from components. More...

virtual	~DAC ()
	Destructor. More...

virtual void	reduceMechanism (const scalar p, const scalar T, const scalarField &c, List< label > &ctos, DynamicList< label > &stoc, const label li)
	Reduce the mechanism. More...

Public Member Functions inherited from chemistryReductionMethod< ThermoType >
	TypeName ("chemistryReductionMethod")
	Runtime type information. More...

	declareRunTimeSelectionTable (autoPtr, chemistryReductionMethod, dictionary,(const IOdictionary &dict, chemistryModel< ThermoType > &chemistry),(dict, chemistry))

	chemistryReductionMethod (chemistryModel< ThermoType > &chemistry)
	Construct from components. More...

	chemistryReductionMethod (const IOdictionary &dict, chemistryModel< ThermoType > &chemistry)
	Construct from components. More...

virtual	~chemistryReductionMethod ()
	Destructor. More...

virtual bool	active () const
	Return mechanism reduction active. More...

label	nSpecie ()
	Return the number of species. More...

label	nActiveSpecies () const
	Return the number of active species. More...

scalar	tolerance () const
	Return the tolerance. More...

const List< bool > &	activeSpecies () const
	Return the active species. More...

bool	reactionDisabled (const label i) const
	Return whether or not a reaction is disabled. More...

virtual void	update ()
	... More...

Additional Inherited Members
Static Public Member Functions inherited from chemistryReductionMethod< ThermoType >
static autoPtr< chemistryReductionMethod< ThermoType > >	New (const IOdictionary &dict, chemistryModel< ThermoType > &chemistry)

Protected Member Functions inherited from chemistryReductionMethod< ThermoType >
void	initReduceMechanism ()
	Protected Member Functions. More...

void	endReduceMechanism (List< label > &ctos, DynamicList< label > &stoc)
	End reduction of the mechanism. More...

Protected Attributes inherited from chemistryReductionMethod< ThermoType >
const dictionary	coeffsDict_
	Dictionary that store the algorithm data. More...

chemistryModel< ThermoType > &	chemistry_
	Reference to the chemistry model. More...

const label	nSpecie_
	Total number of species. More...

label	nActiveSpecies_
	Number of active species. More...

Field< bool >	reactionsDisabled_
	List of disabled reactions (disabled = true) More...

List< bool >	activeSpecies_
	List of active species (active = true) More...

Detailed Description

template<class ThermoType>
class Foam::chemistryReductionMethods::DAC< ThermoType >

The Dynamic Adaptive Chemistry (DAC) method [1] simplify the chemistry using the matrix rAB defined by (DRGEP algorithm [2])

|sum_i=1->Nr vAi wi dBi| rAB = ————————— , max(PA, CA)

PA = sum_i=1->Nr (max (0, vAi wi)) -> production of species A

CA = sum_i=1->Nr (max (0, -vAi wi)) -> consumption of species A

where i is the reaction index, Nr the number of reactions, vAi is the net stoichiometric coefficient of species A in the ith reaction (vAi = v''-v') , wi is the progress variable of reaction i and dBi equals 1 if reaction i involves B and O otherwise. rAB show the error introduced to the production rates of A when B and all the reactions including it are removed. It is computed as in [3] so that the algorithm is O(Nr).

DAC uses a initial set of species that represents the major parts of the combustion mechanism, i.e. H2/O2, fuel decomposition and CO2 production. Usually, it includes the fuel, HO2 and CO. Then it computes the dependence of these set to the other species. This is done by introducing R-value defined by

R_V0 (V) = max_SP(product(rij)),

where SP is the set of all possible paths leading from V0 to V and product(rij) is the chain product of the weights of the edges along the given path. The R-value for the initial set species is 1.

When the R-value of a species is larger than a user-defined tolerance then the species is included in the simplified mechanism. Otherwise, the species is removed along with all the reactions including it.

During this process, instead of looking over all species like described in [1], the algorithm implemented here creates dynamic list to retain the initialised edges only (see [3]).

References:

    [1] Liang, L., Stevens, J. G., & Farrell, J. T. (2009).
    A dynamic adaptive chemistry scheme for reactive flow computations.
    Proceedings of the Combustion Institute, 32(1), 527-534.

    [2] Pepiot-Desjardins, P., & Pitsch, H. (2008).
    An efficient error-propagation-based reduction method for large
    chemical kinetic mechanisms.
    Combustion and Flame, 154(1), 67-81.

    [3] Lu, T., & Law, C. K. (2006).
    Linear time reduction of large kinetic mechanisms with directed
    relation graph: n-Heptane and iso-octane.
    Combustion and Flame, 144(1), 24-36.

Source files