Abstract:

A random search model(RSM) of integrated optimization algorithm for resolving underdetermined jet engine fault equations is presented , which is able to give overall fault diagnosis information in the case that the number of the fault patterns which coexist in the diagnosed engine is less than, equal to, or especially greater than that of the measurements. An estimation of the diagnosis effectiveness of RSM is made by use of computer simulation method for JT9D engine overall performance diagnosis, and a practical test for RSM by use of 24 fault samples of JT9D engine is also conducted . Research results show that six to ten coexisting performance failures of the main components of JT9D engine can be diagnosed with only four measurements,and the index of effectiveness is able to reach 0.89 to 0.94.

Key words: engine performance monitoring, fault diagnosis, Monte Carlo method, random simulation