GAS TURBINE ENGINE ANALYZER

• US 3,731,070 A
• Filed: 04/27/1971
• Issued: 05/01/1973
• Est. Priority Date: 04/27/1971
• Status: Expired due to Term

• Current Assignee: Louis A. Urban
• Original Assignee: Louis A. Urban
• Inventors: Urban, Louis A.
• Primary Examiner(s): Botz, Eugene G.
• Assistant Examiner(s): Didline, Jr., R. Stephen
• Application Number:
  US05/137,924
• Time in Patent Office: 735 Days
• Field of Search: 235/151.3 73/116 444/1
• US Class Current: 701/100
• CPC Class Codes: F01D 21/003 Arrangements for testing or measuring for measuring vibrations G01H
• CPC Class Codes: G07C 3/00 Registering or indicating the condition or the working of machines or other apparatus, other than vehicles

Abstract

The relative health of a gas turbine engine is analyzed and the particular faults are automatically determined by sensing monitored parameters of the gas path of gas turbine engine and electronically computing them into thermodynamically independent variables and comparing the rate of change of this value with a base line value used as a reference datum. A special purpose computer is programmed to include a general influence coefficient matrix containing the independent variables selected to determine the specific fault and serves to thermodynamically simulate the engine'"'"''"'"'s operations.

Claims

1. The method of analyzing the gas path of a gas turbine engine for diagnosing the relative health thereof, comprising the steps of:

measuring a plurality of engine dependent variables, establishing a datum of each of said dependent variables as a function of a predetermined engine dependent variable at a first instance of engine operation, monitoring said dependent variables after subsequent engine operation, computing the differences between said datum obtained in the step of establishing and the monitored engine depeNdent variables, computing the said differences into changes of independent variables, and collating the computed independent variable changes into particular engine faults.

2. The method of analyzing the gas path of a gas turbine engine as claimed in claim 1 including the additional step of computing said engine dependent variable into a value referenced to a predetermined standard base.

3. The method of analyzing the gas path of a gas turbine engine as claimed in claim 1 including the additional step of computing said engine dependent variable into a value referenced to a predetermined standard base to an N.A.C.A. standard day.

4. The method of analyzing the gas path of a gas turbine engine for diagnosing the relative health thereof, comprising the steps of establishing a datum for each of a plurality of engine dependent variables as a function of a predetermined engine dependent variable, sensing said engine dependent variables, generating an electronic signal indicative of the difference between said datum and said sensed engine dependent variables, computing said signal obtained in the step of generating an electronic signal for obtaining electronic output signals indicative of differential changes of engine independent variables, and relating said output signal into particular engine faults.

5. The method as claimed in claim 4 including the step of programing a matrix to contain coefficients of sets of differential equations defining the interrelationships amongst the selected engine dependent and independent variables and solving for the partial derivatives of the differential changes of the independent variables.

6. The method of claim 5 including the step of applying the output obtained in the step of solving to the input of a visual display adapted to receive only one of several outputs for relating the fault to said output.

7. The method of prognosticating the future health of a gas turbine engine comprising the steps of:

registering a datum of each of a plurality of engine dependent variables as a function of a predetermined engine dependent variable, sensing said dependent engine variables, computing the difference between the datum and each of said monitored dependent variables for producing signals indicative of said differences, differentiating said signals into values indicative of differential changes of independent variables, establishing and plotting limits of said independent variables, and plotting over extended periods of time said differential changes of independent variables to visually compare said differential changes of independent variables with said limits.

8. The method as claimed in claim 7 wherein the step of computing includes the step of programming a computer to include a general influence coefficient matrix whose coefficients are a set of differential equations defining the interrelationships of the selected engine dependent and independent variables.

9. The method as claimed in claim 7 including the step of computing said engine dependent variables into values indicative of their corrected values.

10. The method of prognosticating the relative health of a gas turbine engine by analyzing the engine gas path including the steps of:

collecting and storing a plurality of base line data on preselected engine dependent variables measured over a range of a preselected engine dependent variable, sensing said engine dependent variables over the same range of values used to measure these variables, computing the differences obtained from the two immediate preceding steps, programming a computer to compute and produce an output signal indicative of a differential change in independent variables by solving the equation obtained by stored coefficients indicative of the relationship of the selected engine independent and dependent variables with the values obtained in the step of computing, initially storing allowed limits for the selected engine independenT variables and plotting the output signal obtained in the steps of programming and storing the limits over predetermined time intervals.

11. The method of analyzing the gas path of a gas turbine engine for diagnosing the relative health thereof, comprising the steps of establishing a datum for each of a plurality of engine dependent variables as a function of a predetermined engine dependent variable, sensing said engine dependent variables, generating a signal indicative of the difference between said datum and said sensed engine dependent variables, computing said signal obtained in the step of generating a signal into an output signal indicative of differential changes of engine independent variables, and relating said output signal into particular engine faults.