From fef5d5c6281b0083fab80f704dbb525eb19701b9 Mon Sep 17 00:00:00 2001
From: henry <henry>
Date: Fri, 6 Feb 2009 21:01:12 +0000
Subject: [PATCH] From Niklas Nordin: Limit the temperature to the
 boiling-point in parcel.C New urea properties.

---
 src/lagrangian/dieselSpray/parcel/parcel.C       | 54 +++++++++++++++++++++++-
 src/thermophysicalModels/liquids/CH4N2O/CH4N2O.H | 12 ++----
 2 files changed, 55 insertions(+), 11 deletions(-)

diff --git a/src/lagrangian/dieselSpray/parcel/parcel.C b/src/lagrangian/dieselSpray/parcel/parcel.C
index 2805a83..1af2699 100644
--- a/src/lagrangian/dieselSpray/parcel/parcel.C
+++ b/src/lagrangian/dieselSpray/parcel/parcel.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 1991-2008 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 1991-2009 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -297,7 +297,7 @@ bool Foam::parcel::move(spray& sDB)
         ms() -= ms()*(oTotMass-m())/oTotMass;
 
         // remove parcel if it is 'small'
-        if (m() < 1.0e-20)
+        if (m() < 1.0e-12)
         {
             keepParcel = false;
 
@@ -574,6 +574,56 @@ void Foam::parcel::updateParcelProperties
             // Prevent droplet temperature to go too low
             // Mainly a numerical stability issue
             Tnew = max(200.0, Tnew);
+            scalar Td = Tnew;
+
+            scalar pAtSurface = fuels.pv(pg, Td, X());
+            scalar pCompare = 0.999*pg;
+            scalar boiling = pAtSurface >= pCompare;
+            if (boiling)
+            {
+                // can not go above boiling temperature
+                scalar Terr = 1.0e-3;
+                label n=0;
+                scalar dT = 1.0;
+                scalar pOld = pAtSurface;
+                while (dT > Terr)
+                {
+                    n++;
+                    pAtSurface = fuels.pv(pg, Td, X());
+                    if ((pAtSurface < pCompare) && (pOld < pCompare))
+                    {
+                        Td += dT;
+                    }
+                    else
+                    {
+                        if ((pAtSurface > pCompare) && (pOld > pCompare))
+                        {
+                            Td -= dT;
+                        }
+                        else
+                        {
+                            dT *= 0.5;
+                            if ((pAtSurface > pCompare) && (pOld < pCompare))
+                            {
+                                Td -= dT;
+                            }
+                            else
+                            {
+                                Td += dT;
+                            }
+                        }
+                    }
+                    pOld = pAtSurface;
+                    if (debug)
+                    {
+                        if (n>100)
+                        {
+                            Info << "n = " << n << ", T = " << Td << ", pv = " << pAtSurface << endl;
+                        }
+                    }
+                }
+                Tnew = Td;
+            }
         }
 
         // Evaporate droplet!
diff --git a/src/thermophysicalModels/liquids/CH4N2O/CH4N2O.H b/src/thermophysicalModels/liquids/CH4N2O/CH4N2O.H
index 25c336f..2b5b4f4 100644
--- a/src/thermophysicalModels/liquids/CH4N2O/CH4N2O.H
+++ b/src/thermophysicalModels/liquids/CH4N2O/CH4N2O.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 1991-2008 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 1991-2009 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -90,16 +90,10 @@ public:
         :
             liquid(60.056, 705.0, 9.050e+6, 0.218, 0.337, 405.85, 9.3131e+1, 465.0, 1.52e-29, 0.3449, 4.7813e+4),
             rho_(1230.006936, 0, 0, 0, 0, 0),
-            pv_(12.06, -3992.0, 0, 0, 0),
-//            hl_(1463034.50113228, 0, 0, 0, 0, 0), 
-// NN.      we cant use constant heat of vapourisation, the below value is linear (sqrt) interpolation to critical temp
+            pv_(3015.15611544, -185497.059684, -430.223621983, 0.00017405122622, 2.0),
             hl_(705.0, 2534249.0, 0.5, 0.0, 0.0, 0.0),
             cp_(2006.46063673904, 0, 0, 0, 0, 0),
-            // NN: enthalpy, h_, is not used in the sprayModel.
-            // For consistency, the enthalpy is derived from hlat and hl.
-            // It is, however, convenient to have it available.
             h_(-6154107.41641135, 2006.46063673904, 0, 0, 0, 0),
-
             cpg_(811.875582789397, 2099.04089516451, 1627.3, 1603.63660583455, 724.41),
             B_(-0.000383641934194752, 0.447249234048222, -469062.208605302, 5.5628080458239e+18, -2.3040162514986e+21),
             mu_(-51.964, 3670.6, 5.7331, -5.3495e-29, 10),
@@ -107,7 +101,7 @@ public:
             K_(-0.4267, 0.0056903, -8.0065e-06, 1.815e-09, 0, 0),
             Kg_(6.977e-05, 1.1243, 844.9, -148850),
             sigma_(705.0, 1.0, 0.0, 0.0, 0.0, 0), // set to constant
-            D_(147.18, 20.1, 60.056, 28) // NN: Same as nHeptane
+            D_(147.18, 20.1, 60.056, 28) // Same as nHeptane
         {}
         CH4N2O
         (
-- 
2.11.4.GIT