Most current fuel schedules for accelerating or decelerating gas turbines use a limiting non-dimensional fuel flow expressed as a function of some engine parameter such as compressor pressure ratio. Usually the same schedule is used for, for example, accelerating ‘cold’ and ‘hot’ engines. This results in differing acceleration rates and differing usage of surge margins. The paper describes two methods of compensating the fuel schedules to account for the engine’s immediately preceding temperature history. One method uses the temperature response of the aerofoil of blades in the H.P. Compressor. The second method, which appears to be an improvement, uses a ‘delayed’ H.P. Shaft speed signal.

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