From 74d62818afe4c98d9d84f6feb7ac051e67e98fa6 Mon Sep 17 00:00:00 2001
From: Benjamin Faigle <benjamin.faigle@posteo.de>
Date: Tue, 14 Aug 2012 12:43:23 +0000
Subject: [PATCH] implemented inverse function of vapor pressure to get the
temperature at vapor pressure. Verified as 0.1Mpa: 372.755918611338; 1Mpa:
453.035632391467; 10Mpa: 584.149487998528; reviewed Phil
git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@8863 2fb0f335-1f38-0410-981e-8018bf24f1b0
---
dumux/material/components/h2o.hh | 21 ++++++++++++++++
dumux/material/components/iapws/region4.hh | 29 ++++++++++++++++++++++
2 files changed, 50 insertions(+)
diff --git a/dumux/material/components/h2o.hh b/dumux/material/components/h2o.hh
index 70e9db38a6..372a10bbd1 100644
--- a/dumux/material/components/h2o.hh
+++ b/dumux/material/components/h2o.hh
@@ -139,6 +139,27 @@ public:
return Region4::saturationPressure(T);
}
+ /*!
+ * \brief The vapor temperature in \f$\mathrm{[Ka]}\f$ of pure water
+ * at a given pressure.
+ *
+ *\param pressure pressure in \f$\mathrm{[Pa]}\f$
+ *
+ * See:
+ *
+ * IAPWS: "Revised Release on the IAPWS Industrial Formulation
+ * 1997 for the Thermodynamic Properties of Water and Steam",
+ * http://www.iapws.org/relguide/IF97-Rev.pdf
+ */
+ static Scalar vaporTemperature(Scalar pressure)
+ {
+ if (pressure > criticalPressure())
+ pressure = criticalPressure();
+ if (pressure < triplePressure())
+ pressure = triplePressure();
+
+ return Region4::vaporTemperature(pressure);
+ }
/*!
* \brief Specific enthalpy of water steam \f$\mathrm{[J/kg]}\f$.
diff --git a/dumux/material/components/iapws/region4.hh b/dumux/material/components/iapws/region4.hh
index 9464e41f6a..7b3ddce315 100644
--- a/dumux/material/components/iapws/region4.hh
+++ b/dumux/material/components/iapws/region4.hh
@@ -89,6 +89,35 @@ public:
return 1e6*tmp;
}
+
+ /*!
+ * \brief Returns the saturation temperature in \f$\mathrm{[K]}\f$ of pure water at a given
+ * pressure.
+ *
+ *\param pressure pressure of component in \f$\mathrm{[Pa]}\f$
+ *
+ * The saturation pressure is often also called vapor pressure.
+ */
+ static Scalar vaporTemperature(Scalar pressure)
+ {
+ static const Scalar n[10] = {
+ 0.11670521452767e4, -0.72421316703206e6, -0.17073846940092e2,
+ 0.12020824702470e5, -0.32325550322333e7, 0.14915108613530e2,
+ -0.48232657361591e4, 0.40511340542057e6, -0.23855557567849,
+ 0.65017534844798e3
+ };
+ Scalar beta = pow((pressure/1e6 /*from Pa to MPa*/), (1./4.));
+ Scalar beta2 = pow(beta, 2.);
+ Scalar E = beta2 + n[2] * beta + n[5];
+ Scalar F = n[0]*beta2 + n[3]*beta + n[6];
+ Scalar G = n[1]*beta2 + n[4]*beta + n[7];
+
+ Scalar D = ( 2.*G)/(-F -std::sqrt(pow(F,2.) - 4.*E*G));
+
+ Scalar temperature = (n[9] + D - std::sqrt(pow(n[9]+D , 2.) - 4.* (n[8] + n[9]*D)) ) * 0.5;
+
+ return temperature;
+ }
};
} // end namepace IAPWS
--
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