Research on a new flow velocity measuring instrument with type of airfoil

Abstract

This paper presents a low-cost 3D printed fluid velocity measurement instrument. The velocity magnitude and flow angle measuring instrument is designed in the shape of airfoil with excellent aerodynamic performance and high freedom of customization. Multiple precision design possibilities enable airfoil velocity measuring instrument to maintain high measurement accuracy over a wide range. The compatible design reduces overall measurement system complexity and interference during combined measurements of multiple physical parameters. The distribution law of the surface pressure of airfoil models with the incoming flow velocity is discussed, and a weighted method is applied to the design of the airfoil velocity measuring instrument. This design method optimizes the airfoil velocity measuring instrument, ensuring the highest measurement accuracy within its operational range. In contrast, wind tunnel calibration and road tests using the system consisting of airfoil velocity measuring instrument and five-hole probe have been carried out. It can be seen from the calibration results that the airfoil velocity measuring instrument performs better than the five-hole probe in terms of measurement stability and data fitting accuracy. The real road test results of the airfoil velocity measuring instrument and the five-hole probe exhibit remarkable proximity, revealing averagely 1.9% variance in speed and averagely 0.37-degree difference in yaw angle. These findings affirm the functionality and precision of the airfoil velocity measuring instrument.