https://mooseframework.inl.gov
Loading...
Searching...
No Matches
SubChannel1PhaseProblem.h
Go to the documentation of this file.
1//* This file is part of the MOOSE framework
2//* https://mooseframework.inl.gov
3//*
4//* All rights reserved, see COPYRIGHT for full restrictions
5//* https://github.com/idaholab/moose/blob/master/COPYRIGHT
6//*
7//* Licensed under LGPL 2.1, please see LICENSE for details
8//* https://www.gnu.org/licenses/lgpl-2.1.html
9
10#pragma once
11
12#include "ExternalProblem.h"
14#include "SubChannelApp.h"
15#include "QuadSubChannelMesh.h"
16#include "SolutionHandle.h"
17#include <petscdm.h>
18#include <petscdmda.h>
19#include <petscksp.h>
20#include <petscsys.h>
21#include <petscvec.h>
22#include <petscsnes.h>
23#include <limits>
24
29
34{
35public:
38
39 virtual void externalSolve() override;
40 virtual void syncSolutions(Direction direction) override;
41 virtual bool solverSystemConverged(const unsigned int) override;
42 virtual void initialSetup() override;
43
45 const SCMHTCClosureBase * getPinHTCClosure() const { return _pin_HTC_closure; } // optional
47
50 {
51 unsigned int i_ch = 0;
52 Real Re = 1.0;
53 Real S = 0.0;
54 Real w_perim = 0.0;
55
56 FrictionStruct() = delete;
57 FrictionStruct(unsigned int i_ch_, Real Re_, Real S_, Real w_perim_)
58 : i_ch(i_ch_), Re(Re_), S(S_), w_perim(w_perim_)
59 {
60 }
62
65 {
66 Real Re = 1.0;
67 Real Pr = 1.0;
68 unsigned int i_pin = std::numeric_limits<unsigned int>::max(); // sentinel (duct) default
69 unsigned int iz = 0;
70 unsigned int i_ch = 0;
71
72 NusseltStruct() = delete;
73 NusseltStruct(Real Re_, Real Pr_, unsigned int i_pin_, unsigned int iz_, unsigned int i_ch_)
74 : Re(Re_), Pr(Pr_), i_pin(i_pin_), iz(iz_), i_ch(i_ch_)
75 {
76 }
78
80 Real getAddedHeatPin(unsigned int i_ch, unsigned int iz) const
81 {
82 return computeAddedHeatPin(i_ch, iz);
83 }
84
86 Real getAddedHeatDuct(unsigned int i_ch, unsigned int iz) const
87 {
88 return computeAddedHeatDuct(i_ch, iz);
89 }
90
93
95 const PostprocessorValue & getOutletPressure() const { return _P_out; }
96
99
102
103protected:
105 virtual Real computeAddedHeatPin(unsigned int i_ch, unsigned int iz) const = 0;
106
108 virtual Real computeAddedHeatDuct(unsigned int i_ch, unsigned int iz) const;
109
111 void computeWijFromSolve(int iblock);
113 void computeSumWij(int iblock);
115 void computeMdot(int iblock);
117 void computeWijPrime(int iblock);
119 Real computeMixingParameter(unsigned int i_gap, unsigned int iz) const;
121 Real computeSweepFlowMixingParameter(unsigned int i_gap, unsigned int iz) const;
123 void computeDP(int iblock);
125 void computeP(int iblock);
127 virtual void computeh(int iblock) = 0;
130 Real computeT(int iblock);
132 void computeRho(int iblock);
134 void computeMu(int iblock);
136 void computeWijResidual(int iblock);
138 virtual Real getSubChannelPeripheralDuctWidth(unsigned int i_ch) const = 0;
142 PetscErrorCode petscSnesSolver(int iblock,
143 const libMesh::DenseVector<Real> & solution,
146 friend PetscErrorCode formFunction(SNES snes, Vec x, Vec f, void * ctx);
147
149 PetscErrorCode implicitPetscSolve(int iblock);
150
152 virtual void initializeSolution() = 0;
154 void detectDeformation();
155
157 PetscScalar computeInterpolationCoefficients(PetscScalar Peclet = 0.0);
158 PetscScalar
159 computeInterpolatedValue(PetscScalar topValue, PetscScalar botValue, PetscScalar Peclet = 0.0);
160
162 Real computeGravityDir(const MooseEnum & dir) const
163 {
164 switch (dir)
165 {
166 case 0: // counter_flow
167 return 1.0;
168 case 1: // co_flow
169 return -1.0;
170 case 2: // none
171 return 0.0;
172 default:
173 mooseError(name(), ": Invalid gravity direction: expected counter_flow, co_flow, or none");
174 }
175 }
176
190 PetscErrorCode solveAndPopulateEnthalpy(
191 Mat A, Vec rhs, unsigned int first_node, unsigned int last_node, const char * ksp_prefix);
192
193 PetscErrorCode cleanUp();
196 unsigned int _n_blocks;
202 const Real _g_grav;
203 const Real & _kij;
204 unsigned int _n_cells;
205 unsigned int _n_gaps;
206 unsigned int _n_pins;
207 unsigned int _n_channels;
208 unsigned int _block_size;
210 std::vector<Real> _z_grid;
211 Real _one;
213 Real _TR;
219 const bool _compute_power;
221 const bool _pin_mesh_exist;
229 Real _dt;
231 Real _CT;
233 const Real & _P_tol;
235 const int & _P_maxit;
237 const Real & _T_tol;
239 const int & _T_maxit;
241 const Real & _T_relaxation;
243 const unsigned int & _enthalpy_subcycles;
257 const PetscReal & _rtol;
259 const PetscReal & _atol;
261 const PetscReal & _dtol;
263 const PetscInt & _maxit;
268 const Real _dir_grav;
270 const bool _implicit_bool;
278 bool _deformation = false;
286
288 std::unique_ptr<SolutionHandle> _mdot_soln;
289 std::unique_ptr<SolutionHandle> _SumWij_soln;
290 std::unique_ptr<SolutionHandle> _P_soln;
291 std::unique_ptr<SolutionHandle> _DP_soln;
292 std::unique_ptr<SolutionHandle> _h_soln;
293 std::unique_ptr<SolutionHandle> _T_soln;
294 std::unique_ptr<SolutionHandle> _Tpin_soln;
295 std::unique_ptr<SolutionHandle> _Dpin_soln;
296 std::unique_ptr<SolutionHandle> _rho_soln;
297 std::unique_ptr<SolutionHandle> _mu_soln;
298 std::unique_ptr<SolutionHandle> _S_flow_soln;
299 std::unique_ptr<SolutionHandle> _w_perim_soln;
300 std::unique_ptr<SolutionHandle> _q_prime_soln;
301 std::unique_ptr<SolutionHandle> _duct_heat_flux_soln; // Only used for ducted assemblies
302 std::unique_ptr<SolutionHandle> _Tduct_soln; // Only used for ducted assemblies
303 std::unique_ptr<SolutionHandle> _displacement_soln;
304 std::unique_ptr<SolutionHandle> _ff_soln;
305 std::unique_ptr<SolutionHandle> _HTC_soln;
306
308 inline PetscErrorCode createPetscVector(Vec & v, PetscInt n)
309 {
311 LibmeshPetscCall(VecCreate(PETSC_COMM_SELF, &v));
312 LibmeshPetscCall(PetscObjectSetName((PetscObject)v, "Solution"));
313 LibmeshPetscCall(VecSetSizes(v, PETSC_DECIDE, n));
314 LibmeshPetscCall(VecSetFromOptions(v));
315 LibmeshPetscCall(VecZeroEntries(v));
316 PetscFunctionReturn(LIBMESH_PETSC_SUCCESS);
317 }
318
319 inline PetscErrorCode createPetscMatrix(Mat & M, PetscInt n, PetscInt m)
320 {
322 LibmeshPetscCall(MatCreate(PETSC_COMM_SELF, &M));
323 LibmeshPetscCall(MatSetSizes(M, PETSC_DECIDE, PETSC_DECIDE, n, m));
324 LibmeshPetscCall(MatSetFromOptions(M));
325 LibmeshPetscCall(MatSetUp(M));
326 PetscFunctionReturn(LIBMESH_PETSC_SUCCESS);
327 }
328
329 template <class T>
330 PetscErrorCode populateVectorFromDense(Vec & x,
331 const T & solution,
332 const unsigned int first_axial_level,
333 const unsigned int last_axial_level,
334 const unsigned int cross_dimension);
335 template <class T>
336 PetscErrorCode populateDenseFromVector(const Vec & x,
337 T & solution,
338 const unsigned int first_axial_level,
339 const unsigned int last_axial_level,
340 const unsigned int cross_dimension);
341 template <class T>
342 PetscErrorCode populateVectorFromHandle(Vec & x,
343 const T & solution,
344 const unsigned int first_axial_level,
345 const unsigned int last_axial_level,
346 const unsigned int cross_dimension);
347 template <class T>
348 PetscErrorCode populateSolutionChan(const Vec & x,
349 T & solution,
350 const unsigned int first_axial_level,
351 const unsigned int last_axial_level,
352 const unsigned int cross_dimension);
353
359 Vec _prod;
366
392
409
425
427 PetscScalar _added_K = 0.0;
428 PetscScalar _added_K_old = 1000.0;
429 PetscScalar _max_sumWij;
430 PetscScalar _max_sumWij_new;
431 PetscScalar _correction_factor = 1.0;
434
435public:
437};
438
439template <class T>
440PetscErrorCode
442 T & loc_solution,
443 const unsigned int first_axial_level,
444 const unsigned int last_axial_level,
445 const unsigned int cross_dimension)
446{
447 PetscScalar * xx;
448
450 LibmeshPetscCall(VecGetArray(x, &xx));
451 for (unsigned int iz = first_axial_level; iz < last_axial_level + 1; iz++)
452 {
453 unsigned int iz_ind = iz - first_axial_level;
454 for (unsigned int i_l = 0; i_l < cross_dimension; i_l++)
455 {
456 loc_solution(i_l, iz) = xx[iz_ind * cross_dimension + i_l];
457 }
458 }
459 LibmeshPetscCall(VecRestoreArray(x, &xx));
460
461 PetscFunctionReturn(LIBMESH_PETSC_SUCCESS);
462}
463
464template <class T>
465PetscErrorCode
467 const T & loc_solution,
468 const unsigned int first_axial_level,
469 const unsigned int last_axial_level,
470 const unsigned int cross_dimension)
471{
472 PetscScalar * xx;
473
475 LibmeshPetscCall(VecGetArray(x, &xx));
476 for (unsigned int iz = first_axial_level; iz < last_axial_level + 1; iz++)
477 {
478 unsigned int iz_ind = iz - first_axial_level;
479 for (unsigned int i_l = 0; i_l < cross_dimension; i_l++)
480 {
481 auto * loc_node = _subchannel_mesh.getChannelNode(i_l, iz);
482 xx[iz_ind * cross_dimension + i_l] = loc_solution(loc_node);
483 }
484 }
485 LibmeshPetscCall(VecRestoreArray(x, &xx));
486
487 PetscFunctionReturn(LIBMESH_PETSC_SUCCESS);
488}
489
490template <class T>
491PetscErrorCode
493 const T & loc_solution,
494 const unsigned int first_axial_level,
495 const unsigned int last_axial_level,
496 const unsigned int cross_dimension)
497{
498 PetscScalar * xx;
500 LibmeshPetscCall(VecGetArray(x, &xx));
501 for (unsigned int iz = first_axial_level; iz < last_axial_level + 1; iz++)
502 {
503 unsigned int iz_ind = iz - first_axial_level;
504 for (unsigned int i_l = 0; i_l < cross_dimension; i_l++)
505 {
506 xx[iz_ind * cross_dimension + i_l] = loc_solution(i_l, iz);
507 }
508 }
509 LibmeshPetscCall(VecRestoreArray(x, &xx));
510 PetscFunctionReturn(LIBMESH_PETSC_SUCCESS);
511}
512
513template <class T>
514PetscErrorCode
516 T & loc_solution,
517 const unsigned int first_axial_level,
518 const unsigned int last_axial_level,
519 const unsigned int cross_dimension)
520{
521 PetscScalar * xx;
523 LibmeshPetscCall(VecGetArray(x, &xx));
524 Node * loc_node;
525 for (unsigned int iz = first_axial_level; iz < last_axial_level + 1; iz++)
526 {
527 unsigned int iz_ind = iz - first_axial_level;
528 for (unsigned int i_l = 0; i_l < cross_dimension; i_l++)
529 {
530 loc_node = _subchannel_mesh.getChannelNode(i_l, iz);
531 loc_solution.set(loc_node, xx[iz_ind * cross_dimension + i_l]);
532 }
533 }
534 PetscFunctionReturn(LIBMESH_PETSC_SUCCESS);
535}
Real f(Real x)
Test function for Brents method.
const std::vector< double > x
const double M
const double T
const double v
Real PostprocessorValue
PetscFunctionBegin
const std::string & name() const
void mooseError(Args &&... args) const
Base class for friction closures used in SCM.
Base class for the convective heat transfer coefficients (HTC) closures used in SCM.
Base class for turbulent mixing closures used in SCM.
Common class for single phase fluid properties.
Base class for the 1-phase steady-state/transient subchannel solver.
libMesh::DenseMatrix< Real > _DP
const PostprocessorValue & getOutletPressure() const
Get outlet pressure.
void computeP(int iblock)
Computes Pressure per channel for block iblock.
PetscErrorCode populateSolutionChan(const Vec &x, T &solution, const unsigned int first_axial_level, const unsigned int last_axial_level, const unsigned int cross_dimension)
const Real & _mass_flow_equation_relaxation
Equation relaxation factor for mass flow rate in the coupled implicit solve.
const Real & _pressure_equation_relaxation
Equation relaxation factor for pressure in the coupled implicit solve.
PetscErrorCode createPetscVector(Vec &v, PetscInt n)
Petsc Functions.
virtual void syncSolutions(Direction direction) override
const bool _segregated_bool
Segregated solve.
PetscScalar computeInterpolatedValue(PetscScalar topValue, PetscScalar botValue, PetscScalar Peclet=0.0)
const SCMMixingClosureBase * _mixing_closure
Turbulent Mixing closure object.
Real computeSweepFlowMixingParameter(unsigned int i_gap, unsigned int iz) const
Computes and validates the sweep-flow mixing parameter.
const SCMHTCClosureBase * _pin_HTC_closure
HTC closure objects.
const SCMHTCClosureBase * _duct_HTC_closure
Mat _cmc_friction_force_mat
Cross momentum conservation - friction force.
std::unique_ptr< SolutionHandle > _w_perim_soln
PetscErrorCode petscSnesSolver(int iblock, const libMesh::DenseVector< Real > &solution, libMesh::DenseVector< Real > &root)
Computes solution of nonlinear equation using snes and provided a residual in a formFunction.
const PetscReal & _dtol
The divergence tolerance for the ksp linear solver.
PetscErrorCode createPetscMatrix(Mat &M, PetscInt n, PetscInt m)
Real getAddedHeatDuct(unsigned int i_ch, unsigned int iz) const
Return the added heat coming from the duct.
virtual void initializeSolution()=0
Function to initialize the solution & geometry fields.
std::unique_ptr< SolutionHandle > _displacement_soln
Mat _hc_time_derivative_mat
Enthalpy Enthalpy conservation - time derivative.
Mat _cmc_time_derivative_mat
Cross momentum Cross momentum conservation - time derivative.
const SCMFrictionClosureBase * _friction_closure
Friction closure object.
Mat _amc_turbulent_cross_flows_mat
Axial momentum Axial momentum conservation - compute turbulent cross fluxes.
static InputParameters validParams()
PetscErrorCode solveAndPopulateEnthalpy(Mat A, Vec rhs, unsigned int first_node, unsigned int last_node, const char *ksp_prefix)
Solve a linear system (A * x = rhs) with a simple PCJACOBI KSP and populate the enthalpy solution int...
const SCMHTCClosureBase * getDuctHTCClosure() const
const SinglePhaseFluidProperties * _fp
Non-owning pointer to fluid properties user object.
Mat _amc_sys_mdot_mat
Axial momentum system matrix.
Mat _cmc_sys_Wij_mat
Lateral momentum system matrix.
libMesh::DenseMatrix< Real > _WijPrime
void computeRho(int iblock)
Computes Density per channel for block iblock.
const SCMFrictionClosureBase * getFrictionClosure() const
virtual Real getSubChannelPeripheralDuctWidth(unsigned int i_ch) const =0
Function that computes the width of the duct cell that the peripheral subchannel i_ch sees.
Real computeGravityDir(const MooseEnum &dir) const
inline function that is used to define the gravity direction
std::unique_ptr< SolutionHandle > _DP_soln
const MooseEnum _interpolation_scheme
The interpolation method used in constructing the systems.
const bool _staggered_pressure_bool
Flag to define the usage of staggered or collocated pressure.
std::unique_ptr< SolutionHandle > _rho_soln
Mat _mc_sumWij_mat
Matrices and vectors to be used in implicit assembly Mass conservation Mass conservation - sum of cro...
std::unique_ptr< SolutionHandle > _duct_heat_flux_soln
struct SubChannel1PhaseProblem::FrictionStruct _friction_args
void computeDP(int iblock)
Computes Pressure Drop per channel for block iblock.
const Real & _T_tol
Convergence tolerance for the temperature loop in internal solve.
const bool _duct_mesh_exist
Flag that informs if there is a duct mesh or not.
std::unique_ptr< SolutionHandle > _S_flow_soln
void computeWijResidual(int iblock)
Computes Residual Matrix based on the lateral momentum conservation equation for block iblock.
const bool _compute_power
Flag that informs if we need to solve the Enthalpy/Temperature equations or not.
const PostprocessorValue & _P_out
Outlet pressure postprocessor value.
virtual void initialSetup() override
std::unique_ptr< SolutionHandle > _Dpin_soln
Mat _cmc_pressure_force_mat
Cross momentum conservation - pressure force.
const SinglePhaseFluidProperties * getSinglePhaseFluidProperties() const
Get fluid properties object.
std::unique_ptr< SolutionHandle > _P_soln
unsigned int _n_blocks
number of axial blocks
void detectDeformation()
Detects whether pin diameter or duct displacement fields require geometry recalculation.
Mat _amc_time_derivative_mat
Axial momentum conservation - time derivative.
libMesh::DenseMatrix< Real > & _Wij
std::unique_ptr< SolutionHandle > _Tduct_soln
bool _deformation
Flag that activates the effect of deformation (pin/duct) based on the auxvalues for displacement,...
libMesh::DenseMatrix< Real > _Wij_residual_matrix
friend PetscErrorCode formFunction(SNES snes, Vec x, Vec f, void *ctx)
This is the residual Vector function in a form compatible with the SNES PETC solvers.
std::unique_ptr< SolutionHandle > _h_soln
std::unique_ptr< SolutionHandle > _T_soln
virtual void computeh(int iblock)=0
Computes Enthalpy per channel for block iblock.
std::unique_ptr< SolutionHandle > _mu_soln
Real _TR
Flag that activates or deactivates the transient parts of the equations we solve by multiplication.
virtual void externalSolve() override
PetscScalar computeInterpolationCoefficients(PetscScalar Peclet=0.0)
Functions that computes the interpolation scheme given the Peclet number.
Mat _cmc_advective_derivative_mat
Cross momentum conservation - advective (Eulerian) derivative.
bool _time_integrator_checked
Whether the time integrator has been checked for consistency with the implementation.
Vec _hc_added_heat_rhs
Enthalpy conservation - source and sink.
const Real & _P_tol
Convergence tolerance for the pressure loop in external solve.
Mat _amc_friction_force_mat
Axial momentum conservation - friction force.
Real _CT
Turbulent modeling parameter used in axial momentum equation.
virtual Real computeAddedHeatPin(unsigned int i_ch, unsigned int iz) const =0
Pure virtual: daughters provide different implementations.
PetscErrorCode populateDenseFromVector(const Vec &x, T &solution, const unsigned int first_axial_level, const unsigned int last_axial_level, const unsigned int cross_dimension)
Real _pressure_fixed_point_error
Maximum pressure fixed-point update before solution relaxation over the blocks.
Mat _mc_density_pressure_mat
Mass conservation - pressure derivative of transient density.
const bool _compute_viscosity
Flag that activates or deactivates the calculation of viscosity.
Mat _hc_advective_derivative_mat
Enthalpy conservation - advective (Eulerian) derivative;.
const PetscInt & _maxit
The maximum number of iterations to use for the ksp linear solver.
PetscErrorCode populateVectorFromHandle(Vec &x, const T &solution, const unsigned int first_axial_level, const unsigned int last_axial_level, const unsigned int cross_dimension)
PetscErrorCode implicitPetscSolve(int iblock)
Computes implicit solve using PetSc.
const bool _compute_density
Flag that activates or deactivates the calculation of density.
libMesh::DenseVector< Real > residualFunction(int iblock, libMesh::DenseVector< Real > solution)
Computes Residual Vector based on the lateral momentum conservation equation for block iblock & updat...
bool _converged
Variable that informs whether we exited external solve with a converged solution or not.
void computeSumWij(int iblock)
Computes net diversion crossflow per channel for block iblock.
const int & _T_maxit
Maximum iterations for the inner temperature loop.
const Real & _T_relaxation
Relaxation factor for temperature updates in the inner thermal-hydraulic iteration.
const Real & _crossflow_relaxation
Relaxation factor for crossflow updates in the coupled implicit solve.
std::unique_ptr< SolutionHandle > _Tpin_soln
const bool _pin_mesh_exist
Flag that informs if there is a pin mesh or not.
Mat _amc_pressure_force_mat
Axial momentum conservation - pressure force.
void computeMdot(int iblock)
Computes mass flow per channel for block iblock.
const SCMHTCClosureBase * getPinHTCClosure() const
std::unique_ptr< SolutionHandle > _SumWij_soln
const bool _implicit_bool
Flag to define the usage of a implicit or explicit solution.
const int & _P_maxit
Maximum number of pressure iterations; zero selects the solver's existing automatic limit.
std::vector< Real > _z_grid
axial location of nodes
virtual bool solverSystemConverged(const unsigned int) override
const Real & _mass_flow_relaxation
Relaxation factor for mass flow rate updates in the coupled implicit solve.
Mat _amc_cross_derivative_mat
Axial momentum conservation - cross flux derivative.
void computeWijFromSolve(int iblock)
Computes diversion crossflow per gap for block iblock.
const unsigned int & _enthalpy_subcycles
Number of enthalpy, temperature, and property updates performed per flow solve.
void computeMu(int iblock)
Computes Viscosity per channel for block iblock.
PetscErrorCode populateVectorFromDense(Vec &x, const T &solution, const unsigned int first_axial_level, const unsigned int last_axial_level, const unsigned int cross_dimension)
libMesh::DenseMatrix< Real > & _Wij_old
struct SubChannel1PhaseProblem::NusseltStruct _nusselt_args
std::unique_ptr< SolutionHandle > _mdot_soln
Solutions handles and link to TH tables properties.
const MooseEnum _gravity_direction
The direction of gravity.
std::unique_ptr< SolutionHandle > _q_prime_soln
virtual Real computeAddedHeatDuct(unsigned int i_ch, unsigned int iz) const
Non-pure: implemented in the base (or override in a child if needed)
const PetscReal & _rtol
The relative convergence tolerance, (relative decrease) for the ksp linear solver.
const Real & _crossflow_equation_relaxation
Equation relaxation factor for crossflow in the coupled implicit solve.
Vec _amc_gravity_rhs
Axial momentum conservation - buoyancy force No implicit matrix.
Mat _mc_axial_convection_mat
Mass conservation - axial convection.
PetscScalar _added_K
Added resistances for monolithic convergence.
Mat _amc_advective_derivative_mat
Axial momentum conservation - advective (Eulerian) derivative.
Real getAddedHeatPin(unsigned int i_ch, unsigned int iz) const
Return the added heat coming from the fuel pins.
Real computeT(int iblock)
Computes and relaxes Temperature per channel for block iblock.
void computeWijPrime(int iblock)
Computes turbulent crossflow per gap for block iblock.
Real computeMixingParameter(unsigned int i_gap, unsigned int iz) const
Computes and validates the turbulent mixing parameter.
std::unique_ptr< SolutionHandle > _ff_soln
const bool _verbose_subchannel
Boolean to printout information related to subchannel solve.
Mat _hc_cross_derivative_mat
Enthalpy conservation - cross flux derivative.
const PetscReal & _atol
The absolute convergence tolerance for the ksp linear solver.
const Real & _pressure_relaxation
Relaxation factor for pressure updates in the coupled implicit solve.
std::unique_ptr< SolutionHandle > _HTC_soln
Base class for subchannel meshes.
virtual Node * getChannelNode(unsigned int i_chan, unsigned int iz) const =0
Get the subchannel mesh node for a given channel index and elevation index.
structure with the needed information to compute the friction factor at a specific subchannel cell
FrictionStruct(unsigned int i_ch_, Real Re_, Real S_, Real w_perim_)
structure with the needed information to compute the Nusselt number at a specific subchannel cell and...
NusseltStruct(Real Re_, Real Pr_, unsigned int i_pin_, unsigned int iz_, unsigned int i_ch_)