Analytical Calculation Model of the TV3-117 Turboshaft Working Regimes Based on Experimental Data

Abstract

The paper presents a practical and relevant analytical calculation model for free turbine turboshaft working regimes and engine performance. The analytical calculation model is based on a post-processing method that analyzes a series of experimental data, specifically focusing on the percentage variations of the engine’s main parameters from the minimum to the takeoff working regime. The experimental data were acquired from three different types of engines: TV2-117A turboshaft, AI-20K turboprop, and Viper 632-41 turbojet. The analysis method aimed to identify, through calculations, certain similarity parameters that exhibit nearly constant variations or variations within tight limits. These parameters can then be used as approximate constants in the calculation model. By utilizing these constants related to similarity parameters, a mathematical connection between different engine regimes is established; more exactly, for the engine data from a known to unknown regime. In the current case, only the engine data from the takeoff regime are requested to be known, and in this way, the other working regimes of several engines can be calculated.