Multi-Mode Identification of Obtaining the Adequate Model of Turbojet Engine Tj-100a-Z for Diagnostics by Thermalgasdynamic Parameters

Abstract

When monitoring and diagnosing the state of gas turbine engines by thermodynamic parameters, adequate mathematical models of these engines are used. This name means diagnostic methods based on special processing and analysis of the values of thermogasdynamic and other parameters measured on a working turbojet engine [1] using its mathematical model. The most important in the system of technical diagnostics is the mathematical model of the engine. Its creation is a problem since, as a rule, the specifications of engine components are not given in the technical documentation. In this regard, obtaining complete mathematical models of engines for diagnostic purposes is an urgent task. There are various approaches to obtaining the characteristics of nodes and one of them is the use of generalized characteristics, for example, developed at the N.E. Zhukovsky Air Force Engineering Academy at the Department 201 "Theory of Air-Jet Engines" under the direction of Professor Nechayev Yu.N. Experience using such characteristics has shown that such characteristics can be used, but in a fairly narrow range of throttle modes. As a rule, this range was limited to no more than 40 % of the calculated (nominal) mode, which significantly limits the capabilities of the mathematical model of turbojet engines when implementing diagnostics using thermodynamic and dynamic parameters. This article proposes an algorithm developed by the authors a lot of mode identification, implemented as a computer program. As an object of study used turbojet engine TJ-100A-Z manufactured in the Czech Republic. For this, the turbojet engine obtained the characteristics of the main components (compressor, combustion chamber, turbine and nozzle) using the throttle characteristics given in the technical conditions. The calculation results are presented in the form of tables and graphs with error analysis in the calculation before and after identification. The comparison of the errors of the parameters of the throttle characteristics with the errors of the sensors for measuring these parameters is given.