Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 29, 2018 - November 30, 2018
In this study, the frequency fn at which the initial vortex train generated in the jet ejected by the converging nozzle with the entrance pipe was measured, and it was to clarify the determinants of fn. The fn at the Reynolds number Re = 1400 to 5600 was measured. As a result, the fn was changed by changing the length of the entrance pipe, regardless of the same nozzle, the same flow velocity and measurement environment. Also, the fn doesn’t increase linearly with Re, but it rises stepwise. In the simulation, organ pipe resonance inside the nozzle was evaluated. As a result, the resonance frequency was observed at a frequency that the fn was became almost flat of rising stepwise with increasing Re. Therefore, it was found that the frequency of the organ pipe resonance determined by the shape of inside of the nozzle, dominates the fn.
