Variable geometry gas turbine engine fuel and guide vane control

Claim 1

In a gas turbine engine having a gas generator section including a combustor for generating a gas flow, a power turbine section rotatably driven by said gas flow: means for generating a first signal requesting substantial increase in output power of said engine, said first signal means including a throttle for selecting a desired gas generator speed; first means for selectively maintaining the speed of said engine at a first preselected minimum idle speed, said first means comprising a fuel governor control for controlling fuel flow to said combustor, said fuel governor including a fuel metering element and means for sensing actual gas generator speed and adjusting said fuel metering element to minimize the difference between said desired and actual speeds; second means selectively engergizable for maintaining said engine speed at a second preselected idle speed substantially higher than said first idle speed, said second means comprising a solenoid having a plunger engageable with said fuel metering element upon energization of said solenoid; means for generating a second signal anticipatory of said first signal, said second means automatically energized by said second signal; means for adjusting the incidence of gas flow on the power turbine section between first and second dispositions respectively developing minimum and maximum pressure ratios across said power turbine section, said adjusting means responsive to said first signal and said means for sensing actual gas generator speed to adjust said incidence of gas flow to said first disposition during at least a portion of acceleration of said engine; means for sensing temperature of inlet air flow to said gas generator and for sensing pressure in said combustor; and a scheduling valve operably associated with said temperature and pressure sensing means for metering fuel flow to said combustor as a preselected empirical function of said sensed pressure and sensed temperature during engine acceleration, said scheduling valve and said fuel metering element disposed in series relative to said fuel flow.