Devising a method for calculating the turboshaft gas turbine engine performance involving a blade-by-blade description of the multi-stage compressor in a two-dimensional setting

Abstract

The design and adjustment of modern gas turbine engines significantly rely on the use of numerical research methods. This paper reports a method devised for calculating the thermogasdynamic parameters and characteristics of a turboshaft gas turbine engine. The special feature of a given method is a two-dimensional blade-by-blade description of the compressor in the engine system. Underlying the calculation method is a nonlinear mathematical model that makes it possible to describe the established processes occurring in individual nodes and in the engine in general. To build a mathematical model, a modular principle was chosen, involving the construction of a system of interrelated and coordinated models of nodes and their elements. The approach used in modeling a two-dimensional flow in the compressor makes it possible to estimate by calculation a significant number of parameters that characterize its operation. With the help of the reported method, it is possible to estimate the effect of changing the geometric parameters of the compressor height on the characteristics of the engine. To take into consideration the influence of variable modes of air intake or overflow in various cross-sections along the compressor tract, to determine the effect of the input radial unevenness on the parameters of the compressor and engine in general. To verify the method described, the calculation of thermogasdynamic parameters and throttle characteristics of a single-stage turboshaft gas turbine engine with a 12-stage axial compressor was performed. Comparison of the calculation results with experimental data showed satisfactory convergence. Thus, the standard deviation of the calculation results from the experimental data is 0.45 % for the compressor characteristics, 0.4 % for power, and 0.15 % for specific fuel consumption. Development and improvement of methods for calculating the parameters and characteristics of gas turbine engines make it possible to improve the quality of design and competitiveness of locally-made aircraft engines.