Fan R. P. M. control loop stabilization using high rotor speed
First Claim
1. In a twin spool turbofan engine having a high speed spool, a fan spool, and fuel controller, a fan spool control loop stabilization system comprising:
- means for generating a first speed dependent signal as a function of fan spool speed of rotation;
means for generating a second speed dependent signal as a function of the rate of change of the high speed spool speed of rotation;
signal summing means for adding said first speed dependent signal to said second speed dependent signal;
means for comparing said sum with a signal indicative of a desired fan spool speed of rotation and producing therefrom an error signal porportional to the difference therebetween; and
,means for adjusting the flow of fuel to said turbofan engine from said fuel controller in response to said difference signal such that the rotation of the fan spool is equivalent to and stable with said desired fan spool speed of rotation.
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Abstract
A fan spool stabilization loop which improves the stability of the low speed or fan spool in a two spool turbofan engine. In a preferred embodiment, the actual rate of rotation of the high speed spool is compared with the desired rate of rotation determined by integrating the difference between the desired rate of rotation of the fan spool and the actual rate of rotation. The difference therebetween controls the flow of fuel to the turbofan engine. In an alternate preferred embodiment of the invention, the rate of change of rotation of the high speed spool is added to the actual rate of rotation of the fan spool and the result is compared with the desired rate of rotation of the fan spool. The difference therebetween is utilized to control the flow of fuel to the turbofan engine.
20 Citations
6 Claims
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1. In a twin spool turbofan engine having a high speed spool, a fan spool, and fuel controller, a fan spool control loop stabilization system comprising:
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means for generating a first speed dependent signal as a function of fan spool speed of rotation; means for generating a second speed dependent signal as a function of the rate of change of the high speed spool speed of rotation; signal summing means for adding said first speed dependent signal to said second speed dependent signal; means for comparing said sum with a signal indicative of a desired fan spool speed of rotation and producing therefrom an error signal porportional to the difference therebetween; and
,means for adjusting the flow of fuel to said turbofan engine from said fuel controller in response to said difference signal such that the rotation of the fan spool is equivalent to and stable with said desired fan spool speed of rotation. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification