Turbines and Jet Nozzles with Two-Phase Flows

摘要

Peculiarities of the operation of turbines and jet nozzles with two-phase working substances are examined. The method of successive approximations is used to investigate the flow in a nozzle of two-phase flow containing small particles, taking into account high-speed and temperature lag of the particles of gas; results of calculations on an electronic computer, are given, which allow estimating rapidly the basic parameters of outflow of the two-phase flow from the nozzle. It is shown that the presence of a liquid wavy film on the wall of the nozzles leads to considerable losses in the boundary layer and causes considerable lowering of the efficiency of the nozzle. Given in the book is the method of calculation of turbines with two-phase flows with liquid particles, and the basic forms of additional losses are examined: because of the impact of liquid particles against the rotor blades and due to friction against the wavy film covering the surface of the blading. To decrease the losses during impact of the particles against the blades, it is expedient to increase the axial clearance between the nozzle box assembly and the rotor wheel; with this erosional wear of the moving blades decreases. (Author)