Simulation And Experimental Study Of The Cantilever Spring Whistle Sound Characteristics

In recent years, adopting the hydrodynamic type launcher to obtain strength sound wave and ultrasonic. This kind of generator compares with the piezoelectric transmitter is of simple structure, low cost, extremely easy to use and large quantity, also is widely used in industrial production. Fluid power projector is especially suitable for the liquid emulsion, ultrasonic cleaning and other occasions. The reed whistle is widely used. But for its sound characteristics and mechanism is not known for nearly a century, and its research is only concentrated in the air, Brown and Alan Powell studied it in detail. The study of the reed whistle’ mechanism is less, which limit the application and development of reed whistle. In this paper, through numerical simulation, theoretical analysis and experiment to explore the voice characteristics and mechanism of reed whistle, which is for the future application.In this paper, firstly, introduces the domestic and overseas study of reed whistle, and summarizes the sound mechanism of existing research work; Secondly, analyses the different sizes of reed modal by finite element software to observe the change of reed size on its natural frequency and vibration mode; Again, the original experiment schemes are improved, through experiments demonstrate the superiority of the improved experiment system; Finally, study the sound frequency of the reed whistle using experimental method, and the effects of its fundamental frequency, the pressure, reed-nozzle distance and reed size on the reed whistle sound frequency.This work contains the following aspects:Using finite element software simulates and analyses the vibration modal of reed to study its regularity. Simulation results indicate that:(a) as the reed’ other size invariant, change the length of the reed, the vibration modal of reed is increased within the scope of audible sound, but its vibration frequency is decreased with the increase of the length; When the reed’ other size remains the same, change the thickness of the reed, the vibration modal of reed is decreased within the scope of audible sound, but its inherent vibration frequency increased with the increase of thickness;(b) the vibration of the reed mode exist many pattern, when thickness is unchanged, for certain sizes of reeds in some order state, its vibration frequency is very close, and the modal is also very similar; At the same time, when have the same length, the similar situation also appeared. Calibrating the amendatory system, the sound card can meet the requirement of experimental measurement, so as to make the experiment process become more flexible and convenient. And also can lower the experiment cost, easily control the operation. At the same time, users can also through the sound card’s own drive to adjust the parameters of the sound card. And theoretically calculate the Eigen frequency of the reeds in the water.The acoustic characteristic of the reed whistle is studied through experimental method. When nozzle-reed distance is unchanged, using the hydrophone to collect the frequency of the reed and finding that with the increase of pressure appears staircase phenomenon and circulation regression phenomenon, this phenomenon is very similar as the brown’ in the air. May be there is a vortex instability which cause the change of frequency; When the inlet pressure is constant, with the change of the nozzle-reed distance, the reed voice frequency also exist jump phenomena between each other.