diff --git a/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C b/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
index 27306f29c..b4346d59c 100644
--- a/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
+++ b/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
@@ -70,6 +70,8 @@ externalWallHeatFluxTemperatureFvPatchScalarField
     q_(p.size(), 0.0),
     h_(p.size(), 0.0),
     Ta_(p.size(), 0.0),
+    QrPrevious_(p.size()),
+    QrRelaxation_(1),
     QrName_("undefined-Qr"),
     thicknessLayers_(),
     kappaLayers_()
@@ -95,6 +97,8 @@ externalWallHeatFluxTemperatureFvPatchScalarField
     q_(ptf.q_, mapper),
     h_(ptf.h_, mapper),
     Ta_(ptf.Ta_, mapper),
+    QrPrevious_(ptf.QrPrevious_, mapper),
+    QrRelaxation_(ptf.QrRelaxation_),
     QrName_(ptf.QrName_),
     thicknessLayers_(ptf.thicknessLayers_),
     kappaLayers_(ptf.kappaLayers_)
@@ -115,6 +119,8 @@ externalWallHeatFluxTemperatureFvPatchScalarField
     q_(p.size(), 0.0),
     h_(p.size(), 0.0),
     Ta_(p.size(), 0.0),
+    QrPrevious_(p.size(), 0.0),
+    QrRelaxation_(dict.lookupOrDefault<scalar>("relaxation", 1)),
     QrName_(dict.lookupOrDefault<word>("Qr", "none")),
     thicknessLayers_(),
     kappaLayers_()
@@ -156,6 +162,11 @@ externalWallHeatFluxTemperatureFvPatchScalarField
 
     fvPatchScalarField::operator=(scalarField("value", dict, p.size()));
 
+    if (dict.found("QrPrevious"))
+    {
+        QrPrevious_ = scalarField("QrPrevious", dict, p.size());
+    }
+
     if (dict.found("refValue"))
     {
         // Full restart
@@ -185,6 +196,8 @@ externalWallHeatFluxTemperatureFvPatchScalarField
     q_(tppsf.q_),
     h_(tppsf.h_),
     Ta_(tppsf.Ta_),
+    QrPrevious_(tppsf.QrPrevious_),
+    QrRelaxation_(tppsf.QrRelaxation_),
     QrName_(tppsf.QrName_),
     thicknessLayers_(tppsf.thicknessLayers_),
     kappaLayers_(tppsf.kappaLayers_)
@@ -204,6 +217,8 @@ externalWallHeatFluxTemperatureFvPatchScalarField
     q_(tppsf.q_),
     h_(tppsf.h_),
     Ta_(tppsf.Ta_),
+    QrPrevious_(tppsf.QrPrevious_),
+    QrRelaxation_(tppsf.QrRelaxation_),
     QrName_(tppsf.QrName_),
     thicknessLayers_(tppsf.thicknessLayers_),
     kappaLayers_(tppsf.kappaLayers_)
@@ -255,6 +270,9 @@ void Foam::externalWallHeatFluxTemperatureFvPatchScalarField::updateCoeffs()
     if (QrName_ != "none")
     {
         Qr = patch().lookupPatchField<volScalarField, scalar>(QrName_);
+
+        Qr = QrRelaxation_*Qr + (1.0 - QrRelaxation_)*QrPrevious_;
+        QrPrevious_ = Qr;
     }
 
     switch (mode_)
@@ -328,7 +346,11 @@ void Foam::externalWallHeatFluxTemperatureFvPatchScalarField::write
 {
     mixedFvPatchScalarField::write(os);
     temperatureCoupledBase::write(os);
+
+    QrPrevious_.writeEntry("QrPrevious", os);
     os.writeKeyword("Qr")<< QrName_ << token::END_STATEMENT << nl;
+    os.writeKeyword("relaxation")<< QrRelaxation_
+        << token::END_STATEMENT << nl;
 
     switch (mode_)
     {
diff --git a/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.H b/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.H
index 2ee5f4c75..c0bc00c1a 100644
--- a/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.H
+++ b/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.H
@@ -61,6 +61,7 @@ Description
         kappaLayers  | list of thermal conductivites per layer [W/m/K] | yes |
         kappaName    | name of thermal conductivity field | yes  |
         QrName       | name of the radiative field | no | no
+        relaxation   | relaxation factor for radiative field | no | 1
     \endtable
 
     Example of the boundary condition specification:
@@ -77,6 +78,7 @@ Description
         value           uniform 300.0;
         kappaName       none;
         QrName          none;
+        relaxation      1;
     }
     \endverbatim
 
@@ -140,6 +142,12 @@ private:
         //- Ambient temperature / [K]
         scalarField Ta_;
 
+        //- Chache Qr for relaxation
+        scalarField QrPrevious_;
+
+        //- Relaxation for Qr
+        scalar QrRelaxation_;
+
         //- Name of the radiative heat flux
         const word QrName_;