A fluidic sonic oscillator is used as a pulse generator, temperature sensor and flow meter. We proposed an oscillator in which the intermediate position of the loop on the sonic oscillator is open to air. The authors call this oscillator control loop open-type oscillator. We think that it is interesting to study oscillatory phenomena of this oscillator and it is important to pursue possibilities as an oscillator.
In this paper, the oscillation frequency of this control loop open-type oscillator is investigated theoretically and experimentally. We think this oscillator has the same phenomena as the sonic oscillator of which pressure variation at the intermediate position of a loop was nearly zero. However it did not oscillate if there were restrictors at output conduits on the oscillator. At first, we propose a mathematical model. The mathematical model for the oscillator is derived distributed parameter elements model and lumped parameter elements model in accordance with compressibility of the fluid in the control loop.
Next, we analyzed it using digital simulation methods and describing function methods. Theoretical results were confirmed by the experimental ones.
The results obtained can be summarized as follows.
1) We proposed a mathematical model for the control loop open-type oscillator and analyzed it. The results agreed well with experimental results.
2) This oscillator is useful as a pulse generator, temperature sensor and flow meter similar to the sonic oscillator.