Numerical Simulation of Turbine Guide Measurement by Flow Method

Abstract

In order to solve the vortex band problem in the equipment measuring the exhaust area of the turbine guide by the water flow method, the CFD calculation method was used to analyze the flow velocity, pressure, vorticity distribution characteristic values, flow velocity distribution uniformity and velocity-weighted average angle of the equipment without diversion device and the equipment with diversion device. The results show that when the diversion device is not set, there are large-scale surface vortices and sub-surface vortices in the water tank, large-scale backflow above the turbine guide, and there are high-speed and high-vorticity regions in the turbine blades, which leads to the deterioration of the flow regime in the equipment, which has a great impact on the measurement accuracy. After setting up the diversion device, it was found that the uniformity of the flow velocity in the section in the equipment changed significantly, the flow field became more uniform, the characteristic values of the vorticity distribution of the measured section decreased, and the characteristic values of the vorticity distribution on the longitudinal profile of the axis above the turbine guide decreased from 0.672 to 0.403. The evenness of flow velocity distribution and the weighted average angle of velocity in each section were improved, which were increased by 4.3%~5.2% and 1.4%~1.6%.