繰返し形伝搬時間逆数差法による流速変動の測定

抄録

In the previous paper, “Repetitive Inverse Transit Time Difference (RITTD) Method” was proposed as a method to measure velocity and temperature of water with ultrasonic wave.
In this paper, the previous apparatus has improved, and as a result of that the velocity resolution of 0.5mm/s and the measuring time of 50ms have achieved. Its response has been confirmed by the measurement of the velocity of fluctuation for the Karman vortex street in the flow past a circular cylinder. The Strouhal number is calculated from the measured velocity of fluctuation.
Our results correspond with the facts of all other experiments concerned with the Karman vortex street.
This method can be possible to apply as a vortex flowmeter because of well response to the velocity of fluctuation in a few Hz.