VARIABLE AREA FAN NOZZLE FOR ACCOMMODATING A FOREIGN OBJECT STRIKE EVENT

摘要

A gas turbine engine system includes a fan (14) and a fan bypass passage (30) downstream of the fan (14) for conveying a bypass airflow from the fan. A nozzle (40) associated with the fan bypass passage (30) includes a plurality of different positions that influence the bypass air flow. One or more sensors (54) near the fan (14) produce a signal representative of a foreign object F near the fan (14). A controller (44) commands the nozzle (40) to move to a desired one of the plurality of different positions in response to the signal from the sensor (54) to change a pressure ratio across the fan (14) to thereby reduce a mechanical stress on the fan (14).