News:
Pattern Factor Control Based on Fuel Modulation and Passive Optical Sensors
Spectral Sciences, Inc. is working with AFRL and Pratt & Whitney to develop an innovative scheme to control engine pattern factor. The scheme addresses the development of "smart fuel nozzles" equipped with simple passive optical sensors compatible with the environmental constraints of the engine system, and suitable for pattern factor control in staged combustors. These sensors will return signals that are related to temperature pattern factor. The control system makes a relative comparison among the sensors to identify which fuel nozzle(s) to trim.
Combustor temperature pattern factor is a measure of the spatial uniformity of the temperature of the flow exiting a turbine engine combustor. The hot spots measured by temperature pattern factor reduce turbine engine component lifetime and limit the engine designed power density. Active control of pattern factor through fuel flow modulation is one of the most promising technologies to meet the Versatile Affordable Advanced Turbine Engines (VAATE) intelligent engine goals. Any reduction in fleet-averaged pattern factor would result in a major reduction of sustainment costs for both new and legacy aircraft. Potential benefits include increased power density, extended turbine blade life, and reduced life cycle costs in high-performance staged combustors.