Tutorials Manual

Chapter 2: Combustion in Gas-phase Processes
Tutorials Manual
and Oxidizer specified. This is defined on the Complete-Combustion Products subtab.
In this case, the product species are H 2 O and N 2 , where N 2 is included (because
it is part of the fuel and oxidizer mixtures). Note that all of the elements contained in
the fuel and oxidizer species must also appear in the product species.
For this example, there are no inputs on the Basic tab of the Solver panel. We use the
default settings, in which the application first solves a fixed-temperature problem and
then uses the results of this solution as the initial guess to solve the full problem
including the energy equation. On the Advanced tab of the Solver panel, the minimum
bonds of species fractions have been specified as smaller than the default, to aid in
convergence to a physical solution.
On the Continuations panel, 8 additional simulations are specified where the
equivalence ratio is gradually changed. There are no inputs on the Output Control
panels for this problem, since default output options will be used.
2.3.1.3 Project Results
Figure 2-2 shows the steady-state temperatures for the combusting
hydrogen/air/nitrogen mixture. In this case, the temperature peaks at a fuel/air
equivalence ratio or about 1.25. As shown by the molar conversions in Figure 2-3,
neither the fuel nor the oxidizer is completely consumed in this combustor, as a result
of the PSR residence time.
To get the plot in Figure 2-3, be sure to select the “molar_conversion” in the Select Results
panel when the Post-Processor is first launched.
Figure 2-2
Steady-state Gas-phase Combustion—Hydrogen/Air Temperatures
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