From 68e36946fd3cf2bfa6817b1a9371bdd3dfb44f95 Mon Sep 17 00:00:00 2001
From: Kutalmis Bercin <kutalmis.bercin@esi-group.com>
Date: Thu, 21 Mar 2024 15:55:19 +0000
Subject: [PATCH] BUG: externalWallHeatFluxTemperature: prevent FPE in
 mixedEnergy condition (fixes #3123)

---
 .../externalWallHeatFluxTemperatureFvPatchScalarField.C       | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/thermoTools/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C b/src/thermoTools/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
index 9b186b78d0..67f622f2cc 100644
--- a/src/thermoTools/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
+++ b/src/thermoTools/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
@@ -331,7 +331,7 @@ void Foam::externalWallHeatFluxTemperatureFvPatchScalarField::updateCoeffs()
                 Q_->value(this->db().time().timeOutputValue());
 
             refGrad() = (heatPower/gSum(patch().magSf()) + qr)/kappa(Tp);
-            refValue() = 0;
+            refValue() = 293.15;  // prevents FPE, no impact on condition
             valueFraction() = 0;
 
             break;
@@ -342,7 +342,7 @@ void Foam::externalWallHeatFluxTemperatureFvPatchScalarField::updateCoeffs()
                 q_->value(this->db().time().timeOutputValue());
 
             refGrad() = (heatFlux + qr)/kappa(Tp);
-            refValue() = 0;
+            refValue() = 293.15;  // prevents FPE, no impact on condition
             valueFraction() = 0;
 
             break;