115 lines
3 KiB
C++
115 lines
3 KiB
C++
/*---------------------------------------------------------------------------*\
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========= |
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\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
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\\ / O peration |
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\\ / A nd | Copyright (C) 2013-2015 OpenFOAM Foundation
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\\/ M anipulation |
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-------------------------------------------------------------------------------
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License
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This file is part of OpenFOAM.
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OpenFOAM is free software: you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
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Class
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Foam::Euler
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Description
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Euler ODE solver of order (0)1.
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The method calculates the new state from:
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\f[
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y_{n+1} = y_n + \delta_x f
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\f]
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The error is estimated directly from the change in the solution,
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i.e. the difference between the 0th and 1st order solutions:
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\f[
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err_{n+1} = y_{n+1} - y_n
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\f]
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SourceFiles
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Euler.C
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\*---------------------------------------------------------------------------*/
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#ifndef Euler_H
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#define Euler_H
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#include "ODESolver.H"
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#include "adaptiveSolver.H"
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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namespace Foam
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{
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/*---------------------------------------------------------------------------*\
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Class Euler Declaration
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\*---------------------------------------------------------------------------*/
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class Euler
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:
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public ODESolver,
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public adaptiveSolver
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{
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// Private data
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mutable scalarField err_;
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public:
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//- Runtime type information
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TypeName("Euler");
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// Constructors
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//- Construct from ODE
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Euler(const ODESystem& ode, const dictionary& dict);
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// Member Functions
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//- Inherit solve from ODESolver
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using ODESolver::solve;
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//- Solve a single step dx and return the error
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scalar solve
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(
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const scalar x0,
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const scalarField& y0,
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const scalarField& dydx0,
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const scalar dx,
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scalarField& y
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) const;
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//- Solve the ODE system and the update the state
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void solve
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(
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scalar& x,
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scalarField& y,
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scalar& dxTry
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) const;
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};
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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} // End namespace Foam
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// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
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#endif
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// ************************************************************************* //
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