/* $Id: naviersystem.h 2644 2008-02-06 20:40:40Z roystgnr $ *//* The Next Great Finite Element Library. *//* Copyright (C) 2003  Benjamin S. Kirk *//* This library is free software; you can redistribute it and/or *//* modify it under the terms of the GNU Lesser General Public *//* License as published by the Free Software Foundation; either *//* version 2.1 of the License, or (at your option) any later version. *//* This library is distributed in the hope that it will be useful, *//* but WITHOUT ANY WARRANTY; without even the implied warranty of *//* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU *//* Lesser General Public License for more details. *//* You should have received a copy of the GNU Lesser General Public *//* License along with this library; if not, write to the Free Software *//* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */// DiffSystem framework files#include "fem_system.h"// The Navier-Stokes system class.// FEMSystem, TimeSolver and  NewtonSolver will handle most tasks,// but we must specify element residualsclass NavierSystem : public FEMSystem{public:  // Constructor  NavierSystem(EquationSystems& es,               const std::string& name,               const unsigned int number)    : FEMSystem(es, name, number), Reynolds(1.), application(0) {}  // System initialization  virtual void init_data ();  // Element residual and jacobian calculations  // Time dependent parts  virtual bool element_time_derivative (bool request_jacobian);  // Constraint parts  virtual bool element_constraint (bool request_jacobian);  virtual bool side_constraint (bool request_jacobian);  // Mass matrix part  virtual bool mass_residual (bool request_jacobian);  // Indices for each variable;  unsigned int p_var, u_var, v_var, w_var;  // Finite elements for the velocity and pressure on element interiors  FEBase *fe_velocity, *fe_pressure;  // Finite element for the velocity on element sides  FEBase *fe_side_vel;  // The Reynolds number to solve for  Real Reynolds;  // The application number controls what boundary conditions and/or  // forcing functions are applied.  Current options are:  // 0 - discontinuous lid velociy driven cavity  // 1 - homogeneous Dirichlet BC with smooth forcing  unsigned int application;  // Returns the value of a forcing function at point p.  This value  // depends on which application is being used.  Point forcing(const Point& p);};