Measuring technique of three-dimensional periodic unsteady flowfield in turbomachinery,including velocity and pressure fields has been developed.A more effective empirical correlation is proposed to express the sensitivity of single slant hot-wire anemometer output to flow velocity,sensor yaw angle and pitch angle.An improved single slant hot-wire three-dimensional unsteady velocity measuring technique is provided,by which the three-dimensional velocity can be measured with very high accuracy and efficiency within a wide range of the flow angle and velocity.Based on measured three-dimensional velocity field and two-dimensional pressure field,measured by pressure transducer fixed on the casing of turbomachinery,a simple experimental-numerical method has been developed to measure the three-dimensional pressure field.With the help of two-dimensional traverse mechanism,high speed data acquisition system and phase-locked sampling and ensemble averaging technique,the three-dimensional periodic unsteady flowfields at the exit of an axial fan have been successfully measured,and its structure has been revealed.
DownLoad: