Thermophysical Data and Scientific Constants

Introduction

The ThermophysicalData package

Introduces the Chemicals subpackage, which gives the properties of an additional 2000 chemical species
Updates the CoolProp fluid properties engine to version 6.1

Additionally, the ScientificConstants has updated the non-derived physical constants to reflect those in the 2014 release of the CODATA Recommended Values of the Fundamental Physical Constants.

New Thermodynamic Data

Maple 2018 introduces the Chemicals subpackage. This uses a new data source* to give the thermodynamic properties of over 2000 gases, liquids and crystalline species.

* Bonnie J. McBride, Michael J. Zehe, and Sanford Gordon. NASA Glenn Coefficients for Calculating Thermodynamic Properties of Individual Species; 2002; https://www.grc.nasa.gov/WWW/CEAWeb/TP-2002-21556.htm .

The data can be used to study

Chemical equilibrium composition
Reaction constants and spontaneity
Rocket performance
Flame temperatures
Explosion and detonation pressures
And many more applications

Heat of formation and molar mass of gaseous CO₂

Enthalpy and entropy of gaseous CO₂ at 300 K

Application: Adiabatic Flame Temperature of Butane

Liquid butane is burnt with 100% theoretical air at an initial temperature of 298.15 K. The combustion reaction is

C₄H₁₀ (l) + 6.5 O₂ (g)+ 24.44 N₂ (g) → 4 CO₂ (g) + 5 H₂O (g) + 24.44 N₂ (g)

Here, we will calculate the adiabatic flame temperature of the combustion products.

Heat of formation of butane

Enthalpies of the combustion products at a temperature T

Enthalpy of the reactants

Total enthalpy of the combustion products

Equating the enthalpy of the reactants and the enthalpy of the combustion products gives the adiabatic flame temperature

Application: Equilibrium Composition of the Combustion of Carbon Monoxide and Oxygen

One mole of CO and 0.5 moles of O₂ are burned at 3000 K

CO (g) + 0.5 O₂ (g) → CO₂ (g)

The combustion products undergo dissociation and contain CO₂, CO, O and O₂. Here, we will calculate the equilibrium composition of the combustion products

Physical Properties

Enthalpies as a function of temperature

Entropy as a function of temperature

Gibbs Free Energy as a function of temperature

Universal gas constant

Constraints

Balancing the reactants and products gives

CO + 0.5 O₂ = n1 CO₂+ n2 CO + n3 O + n4 O₂

This results in the following constraint on the oxygen atoms...

...and this constraint on the carbon atoms

Total number of moles in products

Equilibrium Composition

For a given temperature, minimizing the Gibbs Free Energy of the combustion products will give the equilibrium molar composition

gibbs := `+`(`*`(n1, `*`(`+`(G_CO2(T), `*`(R, `*`(T, `*`(ln(`/`(`*`(n1), `*`(nt))))))))), `*`(n2, `*`(`+`(G_CO(T), `*`(R, `*`(T, `*`(ln(`/`(`*`(n2), `*`(nt))))))))), `*`(n3, `*`(`+`(G_O(T), `*`(R, `*`...

res := Optimization:-Minimize(eval(gibbs, T = `+`(`*`(3000, `*`(Unit('K'))))), {con1, con2, `>=`(n1, `+`(`*`(0.1e-3, `*`(Unit('mol'))))), `>=`(n2, `+`(`*`(0.1e-3, `*`(Unit('mol'))))), `>=`(n3, `+`(`*`...

Typesetting:-mprintslash([res := [`+`(`-`(`*`(416167.796100690844, `*`(Unit(J))))), [n1 = `+`(`*`(.545813996336248, `*`(Unit(mol)))), n2 = `+`(`*`(.454186003663752, `*`(Unit(mol)))), n3 = `+`(`*`(0.56...

Updated CoolProp Library

Maple 2018 updates the CoolProp library to version 6.1. This includes new fluids and updated routines used to calculate fluid properties.

New fluids include Dichloroethane, DiethylEther, EthyleneOxide, HydrogenChloride, Novec 649^TM and several others

Updated ScientificConstants Package

The non-derived physical constants in the ScientificConstants package now uses the most recent values of the scientific constants published by CODATA.