The combustor overall length to hydraulic diameter ratio is 4.9, and the exit blockage is 45 percent by means of an orifice plate. The only air addition in this configuration is through the dome. The combustor is mounted on a 240 mm length spool piece containing a mounting pad for the fuel injector flange. The combustor and spool piece are situated on an inlet air conditioning section, also shown in Figure 1 . Reactants are supplied at ambient temperature and pressure.
Ignition is by means of a removable torch-ignitor.
This combustion chamber allows the combustion characteristics of a practical injector to be investigated in a simple geometry where various diagnostic measurements can be made. The total air passage effective area is 0.176 in2, with an outer to inner flow split of 2.8. The outer swirler vane angle is 55 degrees while the inner swirler vane angle is 70 degrees. The injector is mounted in a plain bulkhead dome containing insert jets angled at 12.5 degrees into the flame, and radially outwards flowing film cooling jets. This arrangement closely simulates that of an engine combustor.