diff --git a/applications/solvers/multiphase/compressibleInterFoam/phaseEquationsOfState/adiabaticPerfectFluid/adiabaticPerfectFluid.C b/applications/solvers/multiphase/compressibleInterFoam/phaseEquationsOfState/adiabaticPerfectFluid/adiabaticPerfectFluid.C
new file mode 100644
index 0000000000..82a195dca9
--- /dev/null
+++ b/applications/solvers/multiphase/compressibleInterFoam/phaseEquationsOfState/adiabaticPerfectFluid/adiabaticPerfectFluid.C
@@ -0,0 +1,124 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     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 <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "adiabaticPerfectFluid.H"
+#include "volFields.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace phaseEquationsOfState
+{
+    defineTypeNameAndDebug(adiabaticPerfectFluid, 0);
+
+    addToRunTimeSelectionTable
+    (
+        phaseEquationOfState,
+        adiabaticPerfectFluid,
+        dictionary
+    );
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::phaseEquationsOfState::adiabaticPerfectFluid::adiabaticPerfectFluid
+(
+    const dictionary& dict
+)
+:
+    phaseEquationOfState(dict),
+    p0_("p0", dimPressure, dict.lookup("p0")),
+    rho0_("rho0", dimDensity, dict.lookup("rho0")),
+    gamma_("gamma", dimless, dict.lookup("gamma")),
+    B_("B", dimPressure, dict.lookup("B"))
+{}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+Foam::phaseEquationsOfState::adiabaticPerfectFluid::~adiabaticPerfectFluid()
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+Foam::tmp<Foam::volScalarField>
+Foam::phaseEquationsOfState::adiabaticPerfectFluid::rho
+(
+    const volScalarField& p,
+    const volScalarField& T
+) const
+{
+    return tmp<Foam::volScalarField>
+    (
+        new volScalarField
+        (
+            IOobject
+            (
+                "rho",
+                p.time().timeName(),
+                p.mesh(),
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                false
+            ),
+            rho0_*pow((p + B_)/(p0_ + B_), 1.0/gamma_)
+        )
+    );
+}
+
+
+Foam::tmp<Foam::volScalarField>
+Foam::phaseEquationsOfState::adiabaticPerfectFluid::psi
+(
+    const volScalarField& p,
+    const volScalarField& T
+) const
+{
+    return tmp<Foam::volScalarField>
+    (
+        new volScalarField
+        (
+            IOobject
+            (
+                "psi",
+                p.time().timeName(),
+                p.mesh(),
+                IOobject::NO_READ,
+                IOobject::NO_WRITE,
+                false
+            ),
+            (rho0_/(gamma_*(p0_ + B_)))
+           *pow((p + B_)/(p0_ + B_), 1.0/gamma_ - 1.0)
+        )
+    );
+}
+
+
+// ************************************************************************* //
diff --git a/applications/solvers/multiphase/compressibleInterFoam/phaseEquationsOfState/adiabaticPerfectFluid/adiabaticPerfectFluid.H b/applications/solvers/multiphase/compressibleInterFoam/phaseEquationsOfState/adiabaticPerfectFluid/adiabaticPerfectFluid.H
new file mode 100644
index 0000000000..49f5218e49
--- /dev/null
+++ b/applications/solvers/multiphase/compressibleInterFoam/phaseEquationsOfState/adiabaticPerfectFluid/adiabaticPerfectFluid.H
@@ -0,0 +1,115 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2012 OpenFOAM Foundation
+     \\/     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 <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::phaseEquationsOfState::adiabaticPerfectFluid
+
+Description
+    AdiabaticPerfectFluid phase density model.
+
+SourceFiles
+    adiabaticPerfectFluid.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef adiabaticPerfectFluid_H
+#define adiabaticPerfectFluid_H
+
+#include "phaseEquationOfState.H"
+#include "dimensionedTypes.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace phaseEquationsOfState
+{
+
+/*---------------------------------------------------------------------------*\
+                           Class adiabaticPerfectFluid Declaration
+\*---------------------------------------------------------------------------*/
+
+class adiabaticPerfectFluid
+:
+    public phaseEquationOfState
+{
+    // Private data
+
+        //- Reference pressure
+        dimensionedScalar p0_;
+
+        //- Reference density
+        dimensionedScalar rho0_;
+
+        //- The isentropic exponent
+        dimensionedScalar gamma_;
+
+        //- Pressure offset for a stiffened gas
+        dimensionedScalar B_;
+
+
+public:
+
+    //- Runtime type information
+    TypeName("adiabaticPerfectFluid");
+
+
+    // Constructors
+
+        //- Construct from components
+        adiabaticPerfectFluid
+        (
+            const dictionary& dict
+        );
+
+
+    //- Destructor
+    virtual ~adiabaticPerfectFluid();
+
+
+    // Member Functions
+
+        tmp<volScalarField> rho
+        (
+            const volScalarField& p,
+            const volScalarField& T
+        ) const;
+
+        tmp<volScalarField> psi
+        (
+            const volScalarField& p,
+            const volScalarField& T
+        ) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace phaseEquationsOfState
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //