Prediction of energy and cavitation characteristics of high specific speed Francis hydraulic turbines

BACKGROUND: Cavitation is a phenomenon that occurs in vane hydraulic machines: pumps, turbines, when the pressure certain area of flow reaches level saturated steam pressure. Its occurrence depends on design and mode operation turbine. In order to turbine with high cavitation qualities, it necessary be able reliably predict this phenomenon.
 AIMS: The article describes approaches modeling Francis turbines based ANSYS software package.
 METHODS: Using quasi-3D methods was modeled blade system 75 meters head. Hydrodynamic computation carried out single-phase two-phase formulations using CFX RESULTS: path 3D solid model specific speed coefficient ns =283 has been completed. part includes spiral case, stator, guide vane, an impeller draft tube. Computational viscous fluid different modes construct universal characteristic. optimal efficiency found characteristics are calculated. losses elements hydroturbine under various operating determined, zone found. calculated (water-steam). For both sides blade, distribution obtained, which can used judge possibility areas where water column less than vaporization value critical for three most unfavorable dependence constructed. occupied by during visualized, its determined relative surface blade.
 CONCLUSIONS: designed good energy confirmed calculation. This version as initial one further optimization path, improve qualities.