Gaseq
Description:
Gaseq is a MS Windows-based program with a MS Excel interface
that can be used to do combustion equilibrium calculations.
It is intended primarily for gas phase calculations, though
there is a limited facility for condensed phases such as soot.
The program is ideal for performing the types of calculations
required to answer questions like:
• What is the temperature of a stoichiometric propane/oxygen
flame?
• How much do I have to compress air to cause its temperature
to rise to 500K?
• What is the equilibrium concentration of chlorine
atoms in chlorine gas at 1000K?
• Given the rate constant for H + O2 = OH + O, what
is the rate of the reverse reaction?
• What is the temperature and pressure behind a Mach
10 shock in oxygen?
Capabilities:
Using Gaseq, you can perform a number of different types of
calculations. These include:
• Determining compositions at a given temperature and
pressure
• Calculating equilibrium constants (stoichiometric
coefficients, reverse reaction rate given forward rate, etc)
• Performing shock calculations (post shock temperature,
pressure, and composition, incident or reflected shocks, detonation
velocities)
In addition to performing such calculations,
you can also:
• Automatically increment any of the parameters involved
• Define mixtures as a single species
• Calculate viscosities and thermal conductivities of
mxtures of gases
• Save your results in MS Excel spreadsheets
Limitations:
Gaseq has several limitations which affect the accuracy of
the outputs generated under certain circumstances.
• Sound speeds in Gaseq are calculated using frozen
specific heats. While this provides a good approximation for
calculations at low temperatures, the approximation will be
increasingly wrong as temperatures rise.
• Gaseq identifies species from their names, which are
assumed to be unique. If the user is attempting to work with
several species with the same name, Gaseq will always select
the first in the list. This behavior can lead to erroneous
results that may go unnoted.
• The program does not do a very good job of handing
reactions where liquid water is involved
• There are also some minor bugs tied running the program
on different operating systems (there shoudln't be any problems
with the computers in the GIS lab), and maximum numbers of
species or reactants in mixtures (the current version can
handle up to 80)
Basic Inputs:
Gaseq's MS Excel interface is very user friendly. The data,
reactants, products, temps, pressures, properties,etc., are
all on view and easily modified.
Basic Output:
Provided you have input enough information and specified what
you want Gaseq to do, the model will output the solution to
the problem you have input. Typical outputs include temperatures,
compositions, reverse reaction rates, equilibrium reactions,
ideal gas law solutions, and fitted NASA polynomials based
on thermodynamic data.
How to Run the Model:
• Begin by defining initial or final conditions such
as temperatures, pressures, or reactant mixtures. To do this,
simply click on the appropriate cell on the program interface
and enter the information.
• Reactant and product mixtures can be chosen from pre-programmed
sets, or ca be manually entered into the "reactants"
or "products" cells.
• Once you have set the parameters, click on "calculate."
The calculation results will be displayed instantly.
Developer: Gaseq was developed as a freeware research tool by Chris Morley, who maintains a website with additional information.
Faculty Contact: Marco Castaldi
Application:
