Abstract: Aspects of the invention related to a system for providing advance notice of impending contact between a stationary component and a rotating component in a turbine engine. For example, the system can be used to warn of potential contact between a seal holder and a rotor disk in the compressor section of the engine. In one embodiment, a pad or other component can be provided on the stationary seal holder. If the seal holder and the rotor disk approach each other during operation, the pad can contact the rotor disk prior to actual contact between the seal holder and the rotor disk. An optical and/or an acoustic signal can be generated by such contact. The signals can be detected remotely from the point of contact by a signal detection device, thereby avoiding the need to pass wires through the compressor section.

Abstract: A gas turbine engine (12) including a water injection system (56) for providing a flow of water (60) to only a pilot diffusion combustion zone (20) of a dual-mode combustor (10) and not to a pre-mixed combustion zone (18) of the combustor. The selective reduction of peak flame temperature in the pilot flame zone provides a maximum reduction in the production of oxides of nitrogen with a minimum consumption of water. The pilot fuel fraction of the combustor may be increased prior to the initiation of the pilot water injection flow. The flow rate of the pilot injection water may be varied as a function of the power level of the gas turbine, and further as a function of the humidity of the ambient air (36).

Abstract: A gas turbine engine (12) including a water injection system (56) for providing a flow of water (60) to only a pilot diffusion combustion zone (20) of a dual-mode combustor (10) and not to a pre-mixed combustion zone (18) of the combustor. The selective reduction of peak flame temperature in the pilot flame zone provides a maximum reduction in the production of oxides of nitrogen with a minimum consumption of water. The pilot fuel fraction of the combustor may be increased prior to the initiation of the pilot water injection flow. The flow rate of the pilot injection water may be varied as a function of the power level of the gas turbine, and further as a function of the humidity of the ambient air (36).