Effects of Combustion Chamber Geometry Deviations Upon Exit Temperature Profiles for Populations With Varied Service Limitations

The purpose of this continuing research was to investigate the effects of combustion chamber geometry on exit temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 knots) at 7 620 m (25,000 ft) by matching Mach number, equivalence ratio and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution temperature measurements were obtained in the combustion chamber exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating temperature for continuous cruise condition. Geometric deviations of both populations were compared to the reference model. The relationship between combustion chamber exit temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance.