Numerical studies of flow at the spiral case of a radial-axial hydromachine

Abstract

The article represents the results of the numerical study of the spatial flow of an incompressible viscous fluid in the spiral case of the reversible radial-axial hydromachine, designed for head Н=200 m, in turbine mode. The spiral case with the angular coverage for φ сп =360° had round meridian sections, calculated according to the law of constancy of the velocity moment V u r=const. The calculations were performed using the software package FlowER-U for the model with the working wheel diameter D 1 =350mm at the head H=1m. The studies were conducted for the numerical area taking into account or not the stator columns. The number of cells in the grid was about 1.2 million The numerical studies permitted to obtain the distribution of the absolute velocity and its components: the circuit, radial and axial velocities, and the angle of flow, created by a spiral case in typical sections. The analysis of the impact of the presence of the columns on characteristics of the stator flow was carried out. The comparison of the calculated data with the results of gavages studies on hydrodynamic stand showed good quantitative and qualitative agreement.