A vortex whistle has a simple structure with only three components. The frequency of the whistle sound can be adjusted by the amount of blowing. The sound frequency is linearly proportional to the amount of flow in the wide flow range. But when blowing it, we feel strong reaction. It means the whistle has the certain pressure loss. Thus it can be a good flowmeter when the problem of the pressure loss is solved. Here we investigate the flow characteristics of the whistle to the solve the problem.
We carried out variety of experiments for variety of the vortex whistles to know the characteristics. I.e., we investigate the relation between the flow and sound frequency, the flow and pressure loss, the pressure loss and the dimensions of the whistle components and the temperature characteristics. From the experiments, we built a pressure loss experimental model and find condition of how to reduce the pressure loss. Finally we show a design condition of how to design the 6-type flowmeter as an example.