| As is known to all, aircraft engine ignition system is the core of the engine. Whether the engine can run safely and efficiently is depending on the rationality and reliability of ignition system. For ensuring the normal running of ignition system, improving the safety and continuing airworthiness of the aircraft, it is very meaningful to research the faults diagnosis of aircraft engine ignition.There is the possibility of starting or ignition failure in the engine starting process. With the extension of the aircraft operating time, ignition wires, ignition exciter, ignition spark plugs and other components will gradually damage or power down, the phenomenon will resulting in igniting unsuccessfully. These faults and problems reduce the engine starting performance in the ground and air, and it is difficult to find fault in the ground state of the parking engine. It reduces the efficiency of fault diagnosis and extends flight inspection time.Ignition failure in the air will even cause the engine stop and flying accidents.Gas turbine engine ignition system includes the ignition exciter(high-energy ignition),ignition wires and ignition spark plugs. Ignition system faults are mainly concentrated in the ignition wires and ignition exciter, a few faults as ignition spark plugs which causes performance degradation. Typical faults are mainly the local short-circuit in the interior of ignition exciter, abrasions and broken ceramic insulating sleeve in ignition wires, coking,widening or narrowing of the bipolar plate spacing in ignition spark plugs and so on.A method of diagnosing and locating ignition faults is described in LabVIEW8.6 based on Virtual instrument. It is described as follows. Firstly, choose secondary ignition voltage as research object that can show ignition performance immediately. Divide the waveform to four regions for analysis, combine with Fault Tree Analysis method. What is more, collect secondary ignition voltage by referring foreign papers to build a fault database. Then, aircraft engine ignition faults diagnosis system will be created. This system can be used to collect waveform of firing voltages and the corresponding parameters,. In the end, the fault type will be shown visually by comparing tested waveform with typical waveforms in database. |
