Cantilevered Reed Whistle Nozzle Structure And Sound Relationship

In recent years, domestic and international have been carried out in the laboratory cavitation effect of ultrasonic degradation of organic pollutants in water, treatment of polluted water made a lot of progress, especially in refractory organic pollutants, degradation of acoustic cavitation shows a simple, rapid, degradation rate and so on. Domestic and foreign researchers explore the acoustic cavitation and acoustic study method to handling large flow of liquid in the hydrodynamic focusing sounder. Large number of studies have proved that hydrodynamic cavitation device and electric generating ultrasonic cavitation process enhancement of the principle is the same, except that the formation of cavitation methods and means.Reed whistle is a transducer that use of liquid as a power source,1948 first invented and applied to the industry by R. Pohlman, and W. Janovsky, therefore, called the Pohlman-Janovsky whisle. Reed whistle as a simple structure, low cost, easy operation and durability of the unique advantages, particularly in the use of acoustic cavitation in liquids contaminated water when the effects of treatment, compared with electric drive reed whistle ultrasound treatment showed capacity, power consumption, suitable for industrial application.Present in the liquid hydrodynamic generator research, few studies based on mathematical software, and in recent years, computational fluid dynamics (CFD) and the finite element analysis of the rapid development of this area for the provision of new research methods, simulation and combined with experiment, that is more conducive to change reed jet whistle, and where the voice mechanism. In this paper, use computational fluid dynamics software to calculate jet speed, jet pressure and turbulence intensity generated by the parameters studied, the specific contents are as follows:1. On the structure of the reed whistle, using Gambit software to establish the model of two-dimensional computational domain and mesh them to set the boundary conditions. Then using CFD software calculate to obtain jet velocity, dynamic pressure, changes in parameters such as turbulence intensity contour; according to regional settings in the calculation of monitoring the location of the simulated data obtained comparative analysis of changes in the characteristics of the jet; drawing changes in these parameters trend line. 2. Finite element analysis software, the establishment of the finite element model of the reed and the reed vibration calculation of intrinsic shapes, draw natural vibration frequency. Can be further radiated sound field by the acoustic module.3. On the liquid jet from the export of different geometry exhaust, exit velocity, turbulence intensity, pressure and other parameters of the export of the jet's motion, vibration state of the reed. From a combination of both to explore the jet reed vibration modes coupling.4 Obtained reed whistle field signal data through experiments, underwater sensor measurement of the sound field experiment data using mathematical software MATLAB, drew some spectrum analysis, at the same time use voice frequency signal level collected microphones to level the value of the changing trends are analyzed.The results show that:reed whistle structure of the jet nozzle has a greater impact. Acoustic signal with the theoretical calculation appears eigenfrequency close to the reed frequency signal. Two microphone signals received very good comparing to eliminate the interference noise signal is conducive to further analysis.