The Acoustic Characteristics Of The H-v Compound Fluid Sound

Hydrodynamic generator mainly includes Hartmann whistle, the vortex whistle, the rotating flute, the reed whistle and the circular plate whistle. these features are that high-power and high-efficient sound waves are directly generated in the fluid, and its simple structure, sturdy and durable, large capacity, small power consumption etc. So hydrodynamic generator is widely used in petroleum, metallurgy, dust removal, cleaning, noise control and muffler design and so on.Many researchers have been working on further study of Hartmann whistle.On the one hand they study structure of Hartmann whistle, air pressure and other factors on acoustic characteristics experimently, and improve the structure of the whistle by analysis in order to achieve more efficient-stable sound effects. On the other hand they analyze the mechanism of the sound production using the theoretical knowledge focusly. this is a difficult, not only to analyze the main sound field, but also to consider the flow role in the sound field, nevertheless more difficulties expanded since the flow field is always dominant in reality. So far, different researchers give different interpretations, but there has been no complete and unified view.The acoustic characteristics of Hartmann whistle are studied in the experiment, its flow field are imitationed by fluent; the acoustic characteristics of the Hartmann-vortex whistle are studies in the experiment, and are compared with Hartmann whistle in details furtherly.In summary, the main tasks as follows:1. The research progress and application of the Hartmann whistle and the vortex whistle are summarized and introduced.2. The acoustic characteristics of the first sound area of the Hartmann whistle, the best location of the first sound area and the best location of the second sound area are studied, and the first and second best location are compared.3. The acoustic characteristics of the first sound area and the best location of the first sound area of the Hartmann-vortex whistle are studied, and are compared with the Hartmann whistle respectively.4. The flow field of Hartmann whistle are imitationed by fluent. Divided into two parts mostly, other factors being fixed, the nozzle diameter is changed (2mm,4mm), analysis the flow pressure and velocity with changes of the nozzle diameter; the distance between the nozzle and the resonator is changed (2,3 mm), analysis the flow field changes with changes of distances between the nozzle and the resonator,including pressure, velocity changes.