Моделирование Энергетических Характеристик Струйно-Реактивной Турбины

Abstract

The aim of the work is to develop a methodology for studying the gas flow in the flowing part of a jet-reactive turbine stage, consisting of a supply nozzle and an impeller, using the FlowVision software package, as well as calculating the parameters and characteristics of this stage. In the process of modeling and research, a large number of types of boundary conditions, initial grids and adaptation levels, time calculation steps, etc. were used and verified. The results of calculations of the energy characteristics of a jet-reactive turbine when setting the pressure and temperature of the braked flow at the inlet to the stage 701325 Pa (overpressure - 600000 Pa) and 288 K, respectively, and the static pressure at the exit from the stage 1010325 Pa are presented. The characteristics of the turbine on the circumference of the impeller, that is, without taking into account the moment of aerodynamic drag during rotation of the turbine rotor in a viscous gas environment are received. The main parameter necessary for calculating the power and efficiency of the turbine is the moment. It is shown that the circumferential (driving) moment of a jet-reactive turbine during calculations using the FlowVision software package can be determined in several ways, based on the results of the calculated parameters displayed in the information window. Comparison of the values of the driving moment obtained in different ways, including the one-dimensional theory, showed that they differ slightly: up to 12%. The dependences of the change in this moment on the rotor speed are given. The values efficiency of the circumferential power and circumferential efficiency on the rotor speed are obtained, and they are compared with the results of calculating these dependences according to the one-dimensional theory for the calculated and non-calculated regime of flow from the driving nozzle. The highest values of the peripheral power and peripheral efficiency are achieved in the range of rotation speed values of 24000-26000 rpm; maximum values of efficiency are in the range of 45-48%. It is shown that the proposed technique is the most reliable from the point of view of the adequacy of the processes inside the machine and the time-spending from the point of view of calculating the stationary mode. Verification of the obtained results was carried out according to the dependence of the starting moment on the pressure at the inlet of the jet-reactive turbine through comparing the calculation results by using the FlowVision software package with experimental data and the calculation results according to the one-dimensional theory.