“The effect of the nozzle blade pitch on the velocity coefficient of the inflow turbine with partial blading of the runner

Abstract

A numerical experiment with three groups of low-consumption inflow turbine with partial blading of the runner is considered in the paper. Geometric models of turbine stages with partial flapping of the runner with different grid spacing of the nozzle diaphragm have been developed. The object of this study is centripetal turbine stages with partial flapping of the impeller. The subject of the study is the efficiency coefficient and the velocity coefficient of the nozzles of the inflow turbine. The research method is numerical simulation of the working fluid flow using elements of computational gas dynamics. The aim of the study is to determine the effect of the nozzle blade pitch on the efficiency of the nozzle diaphragm of low-consumption inflow turbine with partial blading of the runner. The main objectives of the study are creating geometric models of turbine stages with different nozzle pitch, determining the boundary conditions of the experiment, conducting and processing the results of the experiment. The graphs of the dependence of the nozzle velocity coefficient and the efficiency of the low-consumption inflow turbine stage are provided. A comparative analysis of the nozzle velocity coefficient and the efficiency coefficient of three turbine stages with different grid spacing of the nozzle diaphragm is carried out. The velocity fields of the flow part of the turbine stages and the integral values of the parameters necessary for the three-dimensional calculation are obtained. The influence of the nozzle blade pitch on the velocity coefficient of the nozzle diaphragm and the efficiency coefficient of the turbine stage is determined. The nature and dependence of this geometric parameter on the efficiency of the study object is established, conclusions on further improvement of turbine stages with partial blading of the runner are made.