Selecting Rational Parameters for Ultra-Low Power Two-Stage Axial Turbine With Pressure Stages

Abstract

Ultra-low power turbine drives are used as energy sources in auxiliary power systems, energy units, terrestrial, marine, air and space transport within the confines of shaft power Ntd = 0.01...10 kW. They represent a set of input, output devices and an ultra-low power turbine (ULPT). The main objective of this article is to describe and to validate a new modified method for selecting rational parameters of two-stage axial ULPT with pressure stages that is based on the multi-objective optimization in conditions of initial data uncertainty. Using this method allows to design a high-performance turbine already at the preliminary design. This paper proposes an approach to the development of surrogate models for evaluating the integrated efficiency of two-stage ultra-low power turbine with pressure stages that is based on the use of existing mathematical models of turbine stage efficiency and mass. The paper describes the basic features of subroutine algorithm for parameters optimization and for efficiency criteria evaluating of a two-stage turbine. This method is intended for use at the preliminary design of a turbine drive. Results of optimization through this method can be applied at the stages of 3D gas-dynamic flow simulation, design and manufacturing of a turbine physical model. The method was tested at preliminary design of an air starter turbine for starting a diesel engine in cold climatic conditions. Validation of the method was carried out by comparing the results of optimization calculations and numerical gas-dynamic simulation in the Ansys CFX package. The results indicate a sufficient accuracy of the developed method for selection of two-stage turbine parameters.