cantera/include/cantera/kinetics/solveSP.h
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/**
* @file solveSP.h Header file for implicit surface problem solver (see \ref
* chemkinetics and class \link Cantera::solveSP solveSP\endlink).
*/
/*
* Copyright 2004 Sandia Corporation. Under the terms of Contract
* DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government
* retains certain rights in this software.
* See file License.txt for licensing information.
*/
#ifndef SOLVESP_H
#define SOLVESP_H
#include "cantera/kinetics/InterfaceKinetics.h"
#include "cantera/numerics/SquareMatrix.h"
//! @defgroup solvesp_methods Surface Problem Solver Methods
//! @{
//! This assumes that the initial guess supplied to the routine is far from
//! the correct one. Substantial work plus transient time-stepping is to be
//! expected to find a solution.
const int SFLUX_INITIALIZE = 1;
//! Need to solve the surface problem in order to calculate the surface fluxes
//! of gas-phase species. (Can expect a moderate change in the solution
//! vector; try to solve the system by direct methods with no damping first,
//! then try time-stepping if the first method fails). A "time_scale" supplied
//! here is used in the algorithm to determine when to shut off time-stepping.
const int SFLUX_RESIDUAL = 2;
//! Calculation of the surface problem is due to the need for a numerical
//! Jacobian for the gas-problem. The solution is expected to be very close to
//! the initial guess, and accuracy is needed because solution variables have
//! been perturbed from nominal values to create Jacobian entries.
const int SFLUX_JACOBIAN = 3;
//! The transient calculation is performed here for an amount of time
//! specified by "time_scale". It is not guaranteed to be time-accurate -
//! just stable and fairly fast. The solution after del_t time is returned,
//! whether it's converged to a steady state or not. This is a poor man's time
//! stepping algorithm.
const int SFLUX_TRANSIENT = 4;
// @}
//! @defgroup solvesp_bulkFunc Surface Problem Bulk Phase Mode
//! Functionality expected from the bulk phase. This changes the equations
//! that will be used to solve for the bulk mole fractions.
//! @{
//! Deposition of a bulk phase is to be expected. Bulk mole fractions are
//! determined from ratios of growth rates of bulk species.
const int BULK_DEPOSITION = 1;
//! Etching of a bulk phase is to be expected. Bulk mole fractions are assumed
//! constant, and given by the initial conditions. This is also used whenever
//! the condensed phase is part of the larger solution.
const int BULK_ETCH = 2;
// @}
namespace Cantera
{
//! Method to solve a pseudo steady state surface problem
/*!
* The following class handles solving the surface problem. The calculation
* uses Newton's method to obtain the surface fractions of the surface and
* bulk species by requiring that the surface species production rate = 0 and
* that the either the bulk fractions are proportional to their production
* rates or they are constants.
*
* Currently, the bulk mole fractions are treated as constants.
* Implementation of their being added to the unknown solution vector is
* delayed.
*
* Lets introduce the unknown vector for the "surface problem". The surface
* problem is defined as the evaluation of the surface site fractions for
* multiple surface phases. The unknown vector will consist of the vector of
* surface concentrations for each species in each surface vector. Species
* are grouped first by their surface phases
*
* - C_i_j = Concentration of the ith species in the jth surface phase
* - Nj = number of surface species in the jth surface phase
*
* The unknown solution vector is defined as follows:
*
* C_i_j | kindexSP
* --------- | ----------
* C_0_0 | 0
* C_1_0 | 1
* C_2_0 | 2
* . . . | ...
* C_N0-1_0 | N0-1
* C_0_1 | N0
* C_1_1 | N0+1
* C_2_1 | N0+2
* . . . | ...
* C_N1-1_1 | NO+N1-1
*
* Note there are a couple of different types of species indices floating
* around in the formulation of this object.
*
* kindexSP: This is the species index in the contiguous vector of unknowns
* for the surface problem.
*
* Note, in the future, BULK_DEPOSITION systems will be added, and the
* solveSP unknown vector will get more complicated. It will include the mole
* fraction and growth rates of specified bulk phases
*
* Indices which relate to individual kinetics objects use the suffix KSI
* (kinetics species index).
*
* ## Solution Method
*
* This routine is typically used within a residual calculation in a large code.
* It's typically invoked millions of times for large calculations, and it must
* work every time. Therefore, requirements demand that it be robust but also
* efficient.
*
* The solution methodology is largely determined by the `ifunc` parameter,
* that is input to the solution object. This parameter may have one of the
* values defined in @ref solvesp_methods.
*
* ### Pseudo time stepping algorithm:
* The time step is determined from sdot[], so that the time step
* doesn't ever change the value of a variable by more than 100%.
*
* This algorithm does use a damped Newton's method to relax the equations.
* Damping is based on a "delta damping" technique. The solution unknowns
* are not allowed to vary too much between iterations.
*
* `EXTRA_ACCURACY`: A constant that is the ratio of the required update norm
* in this Newton iteration compared to that in the nonlinear solver. A value
* of 0.1 is used so surface species are safely overconverged.
*
* Functions called:
* - `ct_dgetrf` -- First half of LAPACK direct solve of a full Matrix
* - `ct_dgetrs` -- Second half of LAPACK direct solve of a full matrix.
* Returns solution vector in the right-hand-side vector, resid.
*/
class solveSP
{
public:
//! Constructor for the object
/*!
* @param surfChemPtr Pointer to the ImplicitSurfChem object that
* defines the surface problem to be solved.
* @param bulkFunc Integer representing how the bulk phases should be
* handled. See @ref solvesp_bulkFunc. Currently,
* only the default value of BULK_ETCH is supported.
*/
solveSP(ImplicitSurfChem* surfChemPtr, int bulkFunc = BULK_ETCH);
//! Destructor. Deletes the integrator.
~solveSP() {}
private:
//! Unimplemented private copy constructor
solveSP(const solveSP& right);
//! Unimplemented private assignment operator
solveSP& operator=(const solveSP& right);
public:
//! Main routine that actually calculates the pseudo steady state
//! of the surface problem
/*!
* The actual converged solution is returned as part of the internal state
* of the InterfaceKinetics objects.
*
* Uses Newton's method to get the surface fractions of the surface and
* bulk species by requiring that the surface species production rate = 0
* and that the bulk fractions are proportional to their production rates.
*
* @param ifunc Determines the type of solution algorithm to be used. See
* @ref solvesp_methods for possible values.
* @param time_scale Time over which to integrate the surface equations,
* where applicable
* @param TKelvin Temperature (kelvin)
* @param PGas Pressure (pascals)
* @param reltol Relative tolerance to use
* @param abstol absolute tolerance.
* @return Returns 1 if the surface problem is successfully solved.
* Returns -1 if the surface problem wasn't solved successfully.
* Note the actual converged solution is returned as part of the
* internal state of the InterfaceKinetics objects.
*/
int solveSurfProb(int ifunc, doublereal time_scale, doublereal TKelvin,
doublereal PGas, doublereal reltol, doublereal abstol);
private:
//! Printing routine that optionally gets called at the start of every
//! invocation
void print_header(int ioflag, int ifunc, doublereal time_scale,
int damping, doublereal reltol, doublereal abstol);
//! Printing routine that gets called after every iteration
void printIteration(int ioflag, doublereal damp, int label_d, int label_t,
doublereal inv_t, doublereal t_real, size_t iter,
doublereal update_norm, doublereal resid_norm,
bool do_time, bool final=false);
//! Calculate a conservative delta T to use in a pseudo-steady state
//! algorithm
/*!
* This routine calculates a pretty conservative 1/del_t based
* on MAX_i(sdot_i/(X_i*SDen0)). This probably guarantees
* diagonal dominance.
*
* Small surface fractions are allowed to intervene in the del_t
* determination, no matter how small. This may be changed.
* Now minimum changed to 1.0e-12,
*
* Maximum time step set to time_scale.
*
* @param netProdRateSolnSP Output variable. Net production rate of all
* of the species in the solution vector.
* @param XMolSolnSP output variable. Mole fraction of all of the species
* in the solution vector
* @param label Output variable. Pointer to the value of the species
* index (kindexSP) that is controlling the time step
* @param label_old Output variable. Pointer to the value of the species
* index (kindexSP) that controlled the time step at the previous
* iteration
* @param label_factor Output variable. Pointer to the current factor
* that is used to indicate the same species is controlling the time
* step.
* @param ioflag Level of the output requested.
* @return Returns the 1. / delta T to be used on the next step
*/
doublereal calc_t(doublereal netProdRateSolnSP[], doublereal XMolSolnSP[],
int* label, int* label_old,
doublereal* label_factor, int ioflag);
//! Calculate the solution and residual weights
/*!
* @param wtSpecies Weights to use for the soln unknowns. These are in
* concentration units
* @param wtResid Weights to sue for the residual unknowns.
* @param Jac Jacobian. Row sum scaling is used for the Jacobian
* @param CSolnSP Solution vector for the surface problem
* @param abstol Absolute error tolerance
* @param reltol Relative error tolerance
*/
void calcWeights(doublereal wtSpecies[], doublereal wtResid[],
const Array2D& Jac, const doublereal CSolnSP[],
const doublereal abstol, const doublereal reltol);
/**
* Update the surface states of the surface phases.
*/
void updateState(const doublereal* cSurfSpec);
//! Update mole fraction vector consisting of unknowns in surface problem
/*!
* @param XMolSolnSP Vector of mole fractions for the unknowns in the
* surface problem.
*/
void updateMFSolnSP(doublereal* XMolSolnSP);
//! Update the mole fraction vector for a specific kinetic species vector
//! corresponding to one InterfaceKinetics object
/*!
* @param XMolKinSp Mole fraction vector corresponding to a particular
* kinetic species for a single InterfaceKinetics Object
* This is a vector over all the species in all of the
* phases in the InterfaceKinetics object
* @param isp ID of the InterfaceKinetics Object.
*/
void updateMFKinSpecies(doublereal* XMolKinSp, int isp);
//! Update the vector that keeps track of the largest species in each
//! surface phase.
/*!
* @param CSolnSP Vector of the current values of the surface concentrations
* in all of the surface species.
*/
void evalSurfLarge(const doublereal* CSolnSP);
//! Main Function evaluation
/*!
* @param resid output Vector of residuals, length = m_neq
* @param CSolnSP Vector of species concentrations, unknowns in the
* problem, length = m_neq
* @param CSolnOldSP Old Vector of species concentrations, unknowns in the
* problem, length = m_neq
* @param do_time Calculate a time dependent residual
* @param deltaT Delta time for time dependent problem.
*/
void fun_eval(doublereal* resid, const doublereal* CSolnSP,
const doublereal* CSolnOldSP, const bool do_time, const doublereal deltaT);
//! Main routine that calculates the current residual and Jacobian
/*!
* @param jac Jacobian to be evaluated.
* @param resid output Vector of residuals, length = m_neq
* @param CSolnSP Vector of species concentrations, unknowns in the
* problem, length = m_neq. These are tweaked in order
* to derive the columns of the Jacobian.
* @param CSolnSPOld Old Vector of species concentrations, unknowns in the
* problem, length = m_neq
* @param do_time Calculate a time dependent residual
* @param deltaT Delta time for time dependent problem.
*/
void resjac_eval(SquareMatrix& jac, doublereal* resid,
doublereal* CSolnSP,
const doublereal* CSolnSPOld, const bool do_time,
const doublereal deltaT);
//! Pointer to the manager of the implicit surface chemistry problem
/*!
* This object actually calls the current object. Thus, we are
* providing a loop-back functionality here.
*/
ImplicitSurfChem* m_SurfChemPtr;
//! Vector of interface kinetics objects
/*!
* Each of these is associated with one and only one surface phase.
*/
std::vector<InterfaceKinetics*> &m_objects;
//! Total number of equations to solve in the implicit problem.
/*!
* Note, this can be zero, and frequently is
*/
size_t m_neq;
//! This variable determines how the bulk phases are to be handled
/*!
* Possible values are given in @ref solvesp_bulkFunc.
*/
int m_bulkFunc;
//! Number of surface phases in the surface problem
/*!
* This number is equal to the number of InterfaceKinetics objects
* in the problem. (until further noted)
*/
size_t m_numSurfPhases;
//! Total number of surface species in all surface phases.
/*!
* This is also the number of equations to solve for m_mode=0 system
* It's equal to the sum of the number of species in each of the
* m_numSurfPhases.
*/
size_t m_numTotSurfSpecies;
//! Mapping between the surface phases and the InterfaceKinetics objects
/*!
* Currently this is defined to be a 1-1 mapping (and probably assumed
* in some places)
* m_surfKinObjID[i] = i
*/
std::vector<size_t> m_indexKinObjSurfPhase;
//! Vector of length number of surface phases containing
//! the number of surface species in each phase
/*!
* Length is equal to the number of surface phases, m_numSurfPhases
*/
std::vector<size_t> m_nSpeciesSurfPhase;
//! Vector of surface phase pointers
/*!
* This is created during the constructor
* Length is equal to the number of surface phases, m_numSurfPhases
*/
std::vector<SurfPhase*> m_ptrsSurfPhase;
//! Index of the start of the unknowns for each solution phase
/*!
* i_eqn = m_eqnIndexStartPhase[isp]
*
* isp is the phase id in the list of phases solved by the
* surface problem.
*
* i_eqn is the equation number of the first unknown in the
* solution vector corresponding to isp'th phase.
*/
std::vector<size_t> m_eqnIndexStartSolnPhase;
//! Phase ID in the InterfaceKinetics object of the surface phase
/*!
* For each surface phase, this lists the PhaseId of the
* surface phase in the corresponding InterfaceKinetics object
*
* Length is equal to m_numSurfPhases
*/
std::vector<size_t> m_kinObjPhaseIDSurfPhase;
//! Total number of volumetric condensed phases included in the steady state
//! problem handled by this routine.
/*!
* This is equal to or less than the total number of volumetric phases in
* all of the InterfaceKinetics objects. We usually do not include bulk
* phases. Bulk phases are only included in the calculation when their
* domain isn't included in the underlying continuum model conservation
* equation system.
*
* This is equal to 0, for the time being
*/
size_t m_numBulkPhasesSS;
//! Vector of number of species in the m_numBulkPhases phases.
/*!
* Length is number of bulk phases
*/
std::vector<size_t> m_numBulkSpecies;
//! Total number of species in all bulk phases.
/*!
* This is also the number of bulk equations to solve when bulk equation
* solving is turned on.
*/
size_t m_numTotBulkSpeciesSS;
//! Vector of bulk phase pointers, length is equal to m_numBulkPhases.
std::vector<ThermoPhase*> m_bulkPhasePtrs;
//! Index between the equation index and the position in the kinetic
//! species array for the appropriate kinetics operator
/*!
* Length = m_neq.
*
* ksp = m_kinSpecIndex[ieq]
* ksp is the kinetic species index for the ieq'th equation.
*/
std::vector<size_t> m_kinSpecIndex;
//! Index between the equation index and the index of the
//! InterfaceKinetics object
/*!
* Length m_neq
*/
std::vector<size_t> m_kinObjIndex;
//! Vector containing the indices of the largest species
//! in each surface phase
/*!
* `k = m_spSurfLarge[i]` where `k` is the local species index, i.e., it
* varies from 0 to (num species in phase - 1) and `i` is the surface
* phase index in the problem. Length is equal to #m_numSurfPhases.
*/
std::vector<size_t> m_spSurfLarge;
//! The absolute tolerance in real units. units are (kmol/m2)
doublereal m_atol;
//! The relative error tolerance.
doublereal m_rtol;
//! maximum value of the time step. units = seconds
doublereal m_maxstep;
//! Maximum number of species in any single kinetics operator
//! -> also maxed wrt the total # of solution species
size_t m_maxTotSpecies;
//! Temporary vector with length equal to max m_maxTotSpecies
vector_fp m_netProductionRatesSave;
//! Temporary vector with length equal to max m_maxTotSpecies
vector_fp m_numEqn1;
//! Temporary vector with length equal to max m_maxTotSpecies
vector_fp m_numEqn2;
//! Temporary vector with length equal to max m_maxTotSpecies
vector_fp m_CSolnSave;
//! Solution vector. length MAX(1, m_neq)
vector_fp m_CSolnSP;
//! Saved initial solution vector. length MAX(1, m_neq)
vector_fp m_CSolnSPInit;
//! Saved solution vector at the old time step. length MAX(1, m_neq)
vector_fp m_CSolnSPOld;
//! Weights for the residual norm calculation. length MAX(1, m_neq)
vector_fp m_wtResid;
//! Weights for the species concentrations norm calculation
/*!
* length MAX(1, m_neq)
*/
vector_fp m_wtSpecies;
//! Residual for the surface problem
/*!
* The residual vector of length "dim" that, that has the value
* of "sdot" for surface species. The residuals for the bulk
* species are a function of the sdots for all species in the bulk
* phase. The last residual of each phase enforces {Sum(fractions)
* = 1}. After linear solve (dgetrf_ & dgetrs_), resid holds the
* update vector.
*
* length MAX(1, m_neq)
*/
vector_fp m_resid;
//! Vector of mole fractions. length m_maxTotSpecies
vector_fp m_XMolKinSpecies;
//! Jacobian. m_neq by m_neq computed Jacobian matrix for the local
//! Newton's method.
SquareMatrix m_Jac;
public:
int m_ioflag;
};
}
#endif