diff --git a/src/thermophysicalModels/specie/equationOfState/incompressible/incompressible.C b/src/thermophysicalModels/specie/equationOfState/incompressible/incompressible.C
new file mode 100644
index 0000000000..20185cd2a6
--- /dev/null
+++ b/src/thermophysicalModels/specie/equationOfState/incompressible/incompressible.C
@@ -0,0 +1,59 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 1991-2010 OpenCFD Ltd.
+ \\/ M anipulation |
+-------------------------------------------------------------------------------
+License
+ This file is part of OpenFOAM.
+
+ OpenFOAM is free software: you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ OpenFOAM 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 General Public License
+ for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with OpenFOAM. If not, see .
+
+\*---------------------------------------------------------------------------*/
+
+#include "incompressible.H"
+#include "IOstreams.H"
+
+// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
+
+Foam::incompressible::incompressible(Istream& is)
+:
+ specie(is),
+ rho_(readScalar(is))
+{
+ is.check("incompressible::incompressible(Istream& is)");
+}
+
+
+Foam::incompressible::incompressible(const dictionary& dict)
+:
+ specie(dict),
+ rho_(readScalar(dict.lookup("rho")))
+{}
+
+
+// * * * * * * * * * * * * * * * Ostream Operator * * * * * * * * * * * * * //
+
+Foam::Ostream& Foam::operator<<(Ostream& os, const incompressible& ico)
+{
+ os << static_cast(ico)
+ << token::SPACE << ico.rho_;
+
+ os.check("Ostream& operator<<(Ostream& os, const incompressible& st)");
+ return os;
+}
+
+
+// ************************************************************************* //
diff --git a/src/thermophysicalModels/specie/equationOfState/incompressible/incompressible.H b/src/thermophysicalModels/specie/equationOfState/incompressible/incompressible.H
new file mode 100644
index 0000000000..76589a79e1
--- /dev/null
+++ b/src/thermophysicalModels/specie/equationOfState/incompressible/incompressible.H
@@ -0,0 +1,149 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 1991-2010 OpenCFD Ltd.
+ \\/ M anipulation |
+-------------------------------------------------------------------------------
+License
+ This file is part of OpenFOAM.
+
+ OpenFOAM is free software: you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ OpenFOAM 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 General Public License
+ for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with OpenFOAM. If not, see .
+
+Class
+ Foam::incompressible
+
+Description
+ Incompressible gas/liquid equation of state.
+
+SourceFiles
+ incompressibleI.H
+ incompressible.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef incompressible_H
+#define incompressible_H
+
+#include "specie.H"
+#include "autoPtr.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+ Class incompressible Declaration
+\*---------------------------------------------------------------------------*/
+
+class incompressible
+:
+ public specie
+{
+ // Private data
+
+ //- Density
+ scalar rho_;
+
+
+public:
+
+ // Constructors
+
+ //- Construct from components
+ inline incompressible(const specie& sp, const scalar rho);
+
+ //- Construct from Istream
+ incompressible(Istream&);
+
+ //- Construct from dictionary
+ incompressible(const dictionary& dict);
+
+ //- Construct as named copy
+ inline incompressible(const word& name, const incompressible&);
+
+ //- Construct and return a clone
+ inline autoPtr clone() const;
+
+ // Selector from Istream
+ inline static autoPtr New(Istream& is);
+
+
+ // Member functions
+
+ //- Return density [kg/m^3]
+ inline scalar rho(scalar p, scalar T) const;
+
+ //- Return compressibility rho/p [s^2/m^2]
+ inline scalar psi(scalar p, scalar T) const;
+
+ //- Return compression factor []
+ inline scalar Z(scalar p, scalar T) const;
+
+
+ // Member operators
+
+ inline void operator+=(const incompressible&);
+ inline void operator-=(const incompressible&);
+
+ inline void operator*=(const scalar);
+
+
+ // Friend operators
+
+ inline friend incompressible operator+
+ (
+ const incompressible&,
+ const incompressible&
+ );
+
+ inline friend incompressible operator-
+ (
+ const incompressible&,
+ const incompressible&
+ );
+
+ inline friend incompressible operator*
+ (
+ const scalar s,
+ const incompressible&
+ );
+
+ inline friend incompressible operator==
+ (
+ const incompressible&,
+ const incompressible&
+ );
+
+
+ // Ostream Operator
+
+ friend Ostream& operator<<(Ostream&, const incompressible&);
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#include "incompressibleI.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //
diff --git a/src/thermophysicalModels/specie/equationOfState/incompressible/incompressibleI.H b/src/thermophysicalModels/specie/equationOfState/incompressible/incompressibleI.H
new file mode 100644
index 0000000000..6d9058d40c
--- /dev/null
+++ b/src/thermophysicalModels/specie/equationOfState/incompressible/incompressibleI.H
@@ -0,0 +1,173 @@
+/*---------------------------------------------------------------------------*\
+ ========= |
+ \\ / F ield | OpenFOAM: The Open Source CFD Toolbox
+ \\ / O peration |
+ \\ / A nd | Copyright (C) 1991-2010 OpenCFD Ltd.
+ \\/ M anipulation |
+-------------------------------------------------------------------------------
+License
+ This file is part of OpenFOAM.
+
+ OpenFOAM is free software: you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ OpenFOAM 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 General Public License
+ for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with OpenFOAM. If not, see .
+
+\*---------------------------------------------------------------------------*/
+
+#include "incompressible.H"
+
+// * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //
+
+inline Foam::incompressible::incompressible
+(
+ const specie& sp,
+ const scalar rho
+)
+:
+ specie(sp),
+ rho_(rho)
+{}
+
+
+// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
+
+inline Foam::incompressible::incompressible
+(
+ const word& name,
+ const incompressible& ico
+)
+:
+ specie(name, ico),
+ rho_(ico.rho_)
+{}
+
+inline Foam::autoPtr
+Foam::incompressible::clone() const
+{
+ return autoPtr(new incompressible(*this));
+}
+
+inline Foam::autoPtr
+Foam::incompressible::New(Istream& is)
+{
+ return autoPtr(new incompressible(is));
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
+
+inline Foam::scalar Foam::incompressible::rho(scalar p, scalar T) const
+{
+ return rho_;
+}
+
+inline Foam::scalar Foam::incompressible::psi(scalar, scalar T) const
+{
+ return 0.0;
+}
+
+inline Foam::scalar Foam::incompressible::Z(scalar, scalar) const
+{
+ return 0.0;
+}
+
+
+// * * * * * * * * * * * * * * * Member Operators * * * * * * * * * * * * * //
+
+inline void Foam::incompressible::operator+=(const incompressible& ico)
+{
+ scalar molr1 = this->nMoles();
+
+ specie::operator+=(ico);
+
+ molr1 /= this->nMoles();
+ scalar molr2 = ico.nMoles()/this->nMoles();
+
+ rho_ = molr1*rho_ + molr2*ico.rho_;
+}
+
+inline void Foam::incompressible::operator-=(const incompressible& ico)
+{
+ scalar molr1 = this->nMoles();
+
+ specie::operator-=(ico);
+
+ molr1 /= this->nMoles();
+ scalar molr2 = ico.nMoles()/this->nMoles();
+
+ rho_ = molr1*rho_ - molr2*ico.rho_;
+}
+
+inline void Foam::incompressible::operator*=(const scalar s)
+{
+ specie::operator*=(s);
+}
+
+
+// * * * * * * * * * * * * * * * Friend Operators * * * * * * * * * * * * * //
+
+inline Foam::incompressible Foam::operator+
+(
+ const incompressible& ico1,
+ const incompressible& ico2
+)
+{
+ scalar nMoles = ico1.nMoles() + ico2.nMoles();
+ scalar molr1 = ico1.nMoles()/nMoles;
+ scalar molr2 = ico2.nMoles()/nMoles;
+
+ return incompressible
+ (
+ static_cast(ico1)
+ + static_cast(ico2),
+ molr1*ico1.rho_ + molr2*ico2.rho_
+ );
+}
+
+inline Foam::incompressible Foam::operator-
+(
+ const incompressible& ico1,
+ const incompressible& ico2
+)
+{
+ scalar nMoles = ico1.nMoles() + ico2.nMoles();
+ scalar molr1 = ico1.nMoles()/nMoles;
+ scalar molr2 = ico2.nMoles()/nMoles;
+
+ return incompressible
+ (
+ static_cast(ico1)
+ - static_cast(ico2),
+ molr1*ico1.rho_ - molr2*ico2.rho_
+ );
+}
+
+inline Foam::incompressible Foam::operator*
+(
+ const scalar s,
+ const incompressible& ico
+)
+{
+ return incompressible(s*static_cast(ico), ico.rho_);
+}
+
+inline Foam::incompressible Foam::operator==
+(
+ const incompressible& ico1,
+ const incompressible& ico2
+)
+{
+ return ico2 - ico1;
+}
+
+
+// ************************************************************************* //