The contour lines show values scaled by the thermal conductivity of water at 20☌. Thermal conductivity in the glycol-water mixture as a function of composition and temperature. The variations in thermal conductivity from -10☌ over a range of 110☌ is around 20% for any given composition (from 0.1 to 0.5 mole fraction of glycol). We can see that the thermal conductivity for a mixture of a mole fraction of glycol of 0.1 is 25–30% larger than that of a mixture of 0.5 mole fraction of glycol at any given temperature. The plot below shows the thermal conductivity as a function of the mole fraction of glycol in the mixture and of temperature. An ideal model is used for the thermal conductivity of the mixture. In this case, the thermodynamic model is the UNIFAC VLE. The properties of the coolant - such as heat capacity, thermal conductivity, density, and viscosity - depend on the composition of the mixture and on temperature. Temperature in the cooling channels inside the engine block in a four-cylinder engine. In cold climates, the coolant liquid that flows inside the channels in the engine block is a mixture of glycol and water. The first example is a model of conjugate heat transfer in a four-cylinder combustion engine. Simulating Conjugate Heat Transfer in a Water-Glycol Mixture The last example studies a distillation process, where the thermodynamic properties database is used to calculate the liquid-vapor equilibrium (flash calculations), including condensation and evaporation. The second example is a model of a tubular reactor, where in addition to transport properties, chemical reactions are also taken into account. The first example deals with the calculation of fluid properties for nonisothermal flow. We are going to explore the functionality in the new thermodynamic properties database using three different examples.
CALCULATE ENTHALPY THERMODYNAMICS CALCULATOR SOFTWARE
The Chemical Reaction Engineering Module as of COMSOL® software version 5.3a contains a new thermodynamic properties database with parameters and functions for a vast range of thermodynamic models and properties.įor gas mixtures, the following thermodynamic models are available:įor liquid mixtures and vapor-liquid mixtures, these additional models are available: For example, for flash calculations, thermodynamic models can compute the composition of a liquid mixture at equilibrium with its vapor phase. This model shows how the composition of a coolant mixture affects the boiling point, density, viscosity, thermal conductivity, and heat capacity of an internal combustion engine.įor systems consisting of several phases, thermodynamic models are able to describe the composition of the phases at equilibrium. These descriptions are based on thermodynamic models for properties such as heat of reaction, heat of formation, heat capacity, viscosity, density, thermal conductivity, and diffusivity. We need accurate descriptions of these properties to solve fluid flow problems with heat and mass transfer as well as reacting flow problems. Gas and liquid solutions that consist of mixtures of chemical compounds (species) have properties that depend on both composition and temperature. For systems with several phases, the thermodynamic properties database computes the composition of the phases at equilibrium.Īdding Thermodynamic Models via the Built-In Database For fluid flow and heat and mass transfer, the database can compute viscosity, density, heat capacity, thermal conductivity, and diffusivity of liquids and gases. For reacting systems, the database computes enthalpy of formation and enthalpy of reaction. You can easily describe composition- and temperature-dependent fluid properties using the thermodynamic properties database, available as of version 5.3a of the COMSOL Multiphysics® software.
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