Simulation of energy losses in an inflow turbine with partial blading of the runner

Abstract

Studying the coefficients of kinetic energy losses of the nozzle diaphragm and the runner in an inflow turbine with partial blading of the runner is carried out. It is noted that inflow low-consumption turbines are reliable and productive devices designed to drive various units. Due to their compact size, they are especially in demand in various branches of mechanical engineering. However, in order to increase efficiency and reduce production costs, it is necessary to constantly improve the technology of manufacturing turbine stages. Some inflow turbines are partial, which leads to additional energy losses. Partial stages in which there are no losses from ventilation, namely, turbines with partial flapping of the runner are considered. To simulate such turbines, the ANSYS CFX software package is used in the work. By using ANSYS Design Modeler to create a geometric model and determine boundary conditions, as well as selecting the appropriate grid, the dependences of the loss coefficients in the nozzle and the runner are obtained. The study has shown that the degree of partiality and the Mach number of the turbine stage have a significant impact on the losses coefficients in the exact part of the nozzle and the runner. To account for these dependencies in the modeling process, empirical dependencies, which are an integral part of the design process of inflow turbines, are obtained. The use of the obtained empirical dependences makes it possible to more accurately predict the characteristics and performance of turbines of this type, as well as to supplement the existing mathematical model of the flow in the flow part of a low-consumption inflow turbine with partial blading of the runner.