Abstract: A single stage combustor for a gas turbine having an annular array of outer fuel nozzles arranged about a center axis of the combustor; a center fuel nozzle aligned with the center axis, wherein the center fuel nozzle is substantially smaller than each of the outer fuel nozzles, wherein the combustor includes a pre-mix operating mode in which the center nozzle receives a fuel rich air-fuel mixture.

Abstract: A method for combustion in a combustor in a gas turbine including: fueling the center fuel nozzle with a fuel-rich mixture of gaseous fuel and air and fueling the outer fuel nozzles with a fuel-lean mixture of fuel and air; igniting the fuel-rich mixture injected by the center fuel nozzle while the fuel-lean mixture injected by the outer combustors is insufficient to sustain ignition; stabilizing a flame on the center fuel nozzle using the bluff body and while the outer fuel nozzles inject the fuel-lean mixture; staging fuel to the outer nozzles by increasing a fuel ratio of the fuel-lean mixture, and after the outer nozzles sustain ignition, reducing fuel applied to the center nozzle.

Abstract: A method of determining the temperature inside a combustion liner without making a direct measurement of the actual temperature. The technique is based on a measurement of the frequency of one of the transverse acoustic modes occurring inside the combustion chamber. The frequency is determined from the transverse geometric dimensions of the combustion chamber and the speed of sound in the gas inside the combustion chamber. The speed of sound in the gas is known from thermodynamics to be a function of gas temperature and gas properties. Thus, from a measurement of the resonant frequency and knowing the combustor dimensions and gas properties, the temperature can be determined with accuracy.