Lim C. Devising a method of prediction of the turbine characteristics on the basis of experimental simulation of the gas dynamic processes.

Object of research - the aerodynamic processes in a flow path of turbomachinery. The purpose of the research is devising a method of prediction of the turbine characteristics on the basis of experimental simulation of the gas dynamic processes in annular turbine cascades. Methods of research - the results of the thesis is based on data from the classical aerodynamic experiment. The theoretical propositions are based on the fundamentals of gas dynamics, theory of turbomachinery cascades and numerous mathematical methods. To research the absolute and relative motion of the working fluid used energy equations, continuity and process equations. Tabulated experimental data by analytic functions on the basis of the least-squares method are approximated. To solve the problems of finding extreme of functions used unconditional methods of nonlinear programming. The practical significance of the results for the turbine is to develop design principles the nozzle cascades for the research of non-uniform flow before air turbine rotor cascade, an annular radial diffuser, which allows to obtain characteristics of the annular nozzle cascade in supersonic mode at a relatively low value of compressor compression degree. The experimental air turbine workspace design, which allows us to solve a wide range of problems such as the whole turbine, and its annular cascades separately, is developed. The characteristic prediction method, which is implemented as a software package for the PC, which significantly reduces the time and the quality of predicting the characteristics of the gas turbine is developed. The developed method for predicting the characteristics of the gas turbine can be recommended for use in turbine aerodynamic laboratory. The research results are used in the design and analysis of gas turbines flow path in the scientific and technical cooperation NTU "KhPI" with the company Samsung TechWin (South Korea) and in the study process turbine department of NTU "KhPI". Scientific novelty - for the first time the method of characteristics definition for high temperature and high speed gas turbine was developed, based on the results of aero-dynamic experimental research of rotor cascade within its own nozzle cascade and special additional ones at medium temperatures, expansion ratios, frequencies of rotating and hydro-brake power; the methodology of aero-dynamic supersonic nozzle cascades characteristics experimental definition was further evolved within the conditions of their mutual work with a diffusor element, which allows to reach high supersonic velocities at relatively low pressure level of compressing equipment; the influence defining method of periodically non-stationary processes and tip clearance size on the integral losses in gas turbine rotor cascade in a wide range modes. Degree of introduction - Turbine Building Department NTU "KPI", Samsung TehWin Company, South Korea. Industry of application - the turbine building.