GB1378694A - Gas turbine engine analyzer - Google Patents

Abstract

1378694 Analyzing gas turbine engines UNITED AIRCRAFT CORP 9 June 1972 27038/72 Heading G1N In a gas turbine engine analyzer, a datum for each of a plurality of corrected dependent engine variables is computed as a function of a selected engine variable, the corrected dependent engine variables are then continuously or intermittently monitored, a value for each monitored variable being computed as a function of the selected variable, the differences between each computed value of the monitored variables and its associated datum are computed to produce respective signals, these signals are computed into differential changes of independent engine variables to produce a second signal, and means are responsive to the second signal to relate the differential changes to particular engine faults. The dependent variables are selected from the group consisting of temperatures, pressure, fuel flow rates, rotor speeds and output power while the independent variables include air-flow rates, turbine inlet temperature, component efficiencies and effective nozzle and exhaust areas. The computing of the difference signals into differential changes of independent variables includes programming a matrix to contain coefficients of sets of differential equations defining the inter-relationships among the dependent and independent variables and solving by determinants or matrix inversion. Fault indicators in the form of windows which light up or paper printout are provided for indicating the area of fault and the possible causes. Further, a progrosis section is provided which compares the differential changes of the independent variables with stored pre-set limits to indicate the likelihood of a fault in the future.