Development and Verification of an Imrpoved Thermo Dynamical Model for Single Spool Jet Engines

Abstract

The main goal of the present research is to develop and verify an improved mathematical model for the thermo dynamical analyses of single spool jet engines with and without afterburner at start position. The specific points of the thermo-dynamical cycles and the main characteristics of the engines are determined by a concentrated parameter-distribution type method, which is implemented in MATLAB environment. The governing equations are based on the mass, the energy balance and the real thermo dynamical processes, in which the mechanical, isentropic and burning efficiencies, pressure losses and power reduction rate of the auxiliary systems are considered. Nonlinear constraint optimization is used for parameter sensitivity analyses and to fit the unknown parameters for the available data as thrust and thrust specific fuel consumption. Material properties, ambient conditions, incoming air mass flow rate, pressure ratio of the compressor, turbine inlet total temperature and the length and diameter of the engines are imposed as input parameters for the analyses. The temperature and component mass fraction dependent gas properties are determined by iteration cycles. Among the results of the analyses, the thrust and thrust specific fuel consumption are compared to available operational data of the ВД-7, КР7-300 (w/o afterburner) and РД-9Б (w/ afterburner) engines. The corner points of the thermo-dynamical cycles are plotted in T-s diagrams for the ВД-7 and РД-9Б engines.