| 摘要 |
<p>A method of, and a system for, detecting an occurrence of a surge in a gas turbine engine. The method includes steps, executed during individual ones of a plurality of consecutively occurring time periods, of: (a) obtaining a filtered derivative of a first engine operating characteristic; (b) obtaining a filtered derivative of a second engine operating characteristic; (c) comparing the filtered derivative of the first engine operating characteristic to a first threshold value; and (d) comparing the filtered derivative of the second engine operating characteristic to a second threshold value. A next step (e) increments a count only if (i) the filtered derivative of the first engine operating characteristic exceeds the first threshold value, and also if (ii) the filtered derivative of the second engine operating characteristic exceeds the second threshold value. Otherwise, a next step (f) decrements the count if the filtered derivative of the first engine operating characteristic does not exceed the first threshold value and/or if the filtered derivative of the second engine operating characteristic does not exceed the second threshold value. The method further includes a step of (g) indicating a surge condition only if the count is equal to a predetermined value that is greater than unity, for example five. In a presently preferred embodiment of this invention the engine is a turbofan engine, the first engine operating characteristic is fan speed, and the second engine operating characteristic is exhaust gas temperature. <IMAGE></p> |
