Thermodynamic Design of a Small-Scale Gas Turbine Engine Family

Abstract

The paper presents a procedure for selecting work cycle parameters and describes thermodynamic design of a small-scale gas turbine engine family consisting of a small-scale gas turbine engine and a gas turbine plant comprising a free turbine driving a power generator, on the basis of a standardized gas generator. In order to select reasonable work cycle parameter values for the small-scale gas turbine engine and gas turbine plant we used a non-linear optimisation technique accounting for functional and parametric constraints as implemented in the ASTRA CAE software. Calculation results allowed us to plot the locally optimal work cycle parameter regions for the small-scale gas turbine engine and gas turbine plant according to the efficiency criteria for both engines, which are specific fuel consumption and net energy conversion efficiency. Taking the constraints into account, we selected reasonable values for the standardized gas generator parameters within the compromise region obtained, specifically the turbine inlet temperature and compressor pressure ratio. Our quantitative results show how the efficiency indices decline in the engine family featuring a standardized gas generator as compared to engines equipped with individually tailored gas generators. Designing a standardized gas generator in advance makes it possible to decrease engine development costs and time, ensure a higher reliability and a lower cost of production.