Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 07, 2019 - November 08, 2019
In this study, we investigate the thrust force and velocity fields in the wake in a periodic flow for changing pitching angle and frequency of pitching NACA 0012 airfoil. The pitching angle and frequency are changed in the range of 2 to 12 deg and 250 to 750 mHz, respectively. The thrust force and velocity fields in the wake are measured using a load cell and particle image velocimetry (PIV), respectively. For comparison, experiments in a steady flow and a periodic flow are carried out with the same experimental conditions at Reynolds number of 4000. FFT analysis is conducted to investigate the difference in the thrust force spectrum between a steady flow and a periodic flow. It is found that two peaks of the thrust force spectrum occur in periodic flow in addition to peak in a steady flow. As pitching frequency increases, the peak frequency of the spectrum increases. As the pitching angle increases, the peak intensity of the spectrum increases. FFT analysis is conducted to investigate the relationship between the thrust force and velocity field in the wake. It is found that the peak frequency of the thrust force spectrum correlates with the peak frequency of the velocity spectrum in the wake.
