Mechanism And Characteristics Of Sentence Based On Two - Way Fluid - Solid Coupling Reed

This paper calculate the vibration problem of the liquid jet incentives the reed that directly facing the nozzle on the platform of Workbench, according to the calculation results to explore the mechanism of the vibration of the reed whistle, and using the Origin accomplish the fast Fourier transform to the results of numerical calculation, analysis the vibration of the free end from the frequency spectrum. Secondly, collecting and recording the sound signal of the reed whistle with 3560 PULSE system, and analysis the signal spectrum of the recording. According to the vibration frequency spectrum of numerical calculation and experimental measurement, analysis the structure parameters of nozzle, the spray distance, jet pressure influence to the sound pressure level and reed vibration frequency. Then, comparing the results of numerical calculation and experimental measurement results, looking for the same and the difference, and analyze the causes of the differences. Finally, putting forward the optimization of the ideas and measures about the reed, the structure parameters of nozzle, the spray distance. Specific research content is as follows:(1) The exploration of the reed vibration mechanism about reed whistle:when the liquid jet incentives the reed that directly facing the nozzle, the free end of reed has tiny displacement because of the vibration of the liquid jet, there will be a certain angle between the reed string and the jet, causing the jet have different velocity which distributed in the upper and lower surface of the reed., thus, the jet will form difference force between upper and lower, The free end of the reed will produce movement under the difference force. But due to reed the tail is fixed and spring action, when the Angle and reed stress reaches a certain value, the restoring force of reed stiffness generated,the free end will move to the opposite direction, so that the vibration of the reed for periodic.(2) The influence of jet pressure on the vibration characteristics of reeds:Jet actuator reed multiple harmonic vibration, resonance frequency distributions comply with the law of the elastic vibration material. With the increase of jet pressure, each frequency doubling of the spectrum of reed peak corresponds to the sound pressure level increases gradually, When working in low jet pressure, each vibration peak sound pressure level change is bigger as the change of injection pressure at low pressure is within the scope of work; Comparative analysis shows:Due to the pressure on the nozzle for a constant value in the numerical calculation, but the experimental measurement on the nozzle pressure is not stable, thus causing jet fluid in the process of experiment has a wider band, excitation more inherent frequency of reed, so the experimental measurement’s peak frequency doubling more than the numerical calculation. The experimental measurement results unlike the numerical results, with the increase of jet pressure, the loudest level corresponding vibration of experimental measurements summit jump. In the experimental measurement, because the organic glass flume border form, sound waves form a standing wave, so the hydrophone monitoring to each vibration peak sound pressure level is not the sound pressure level accurately, thus the experimental measurement with the increase of jet pressure, the loudest level corresponding vibration summit jump.(3) The influence of nozzle structure parameters on the vibration characteristics of reeds:With the decrease of the nozzle width rectangle structure, the frequency of the reed’s main and doubling peak will move to right, and each vibration peak corresponds to the sound pressure level decreases. Using Fast Fourier transform to the vibration displacement with time of the reed free end in numerical calculation, do not have these physical parameters about the transfer between electricity and sound, benchmark acoustic pressure et al, so the sound pressure level of vibration peak is vary widely between the results of numerical calculation and experimental measurement results(4) The influence of the spray distance on characteristic of reed:under the same jet pressure, the frequency of the first peak will jump with the increase of the spraying distance, and within a certain range of spray distance, the total sound pressure level is reduced, but decrease to a certain value and then gradually increase, will eventually be stabilized; Under the same spray distance, the frequency of the first peak will jump with the increase of jet pressure, and the total sound pressure level increase; Because the model of numerical calculation is ideal model, in the same working condition, the resonant peak corresponding vibration frequency of the numerical results is less than the experimental measurement results.(5) Optimization ideas and measures of the experiments:choose vibration fatigue resistance strong metal, but its elastic modulus should not be too large; The reed free end under the same amplitude, the equivalent stress of the trapezoid reed is more dispersed relative the rectangular reed, so the vibration fatigue resistance is stronger; The reed thickness of tail section should be designed as a gradient form, this can increase the ability to resist vibration fatigue. The Nozzle’s width equal to the free end width of reed, this will avoid wasting energy; Nozzle structure parameters optimization should follow the venture-tube hydraulic cavitation principles of optimization, increase of liquid jet’s steam containing rate as much as possible. Spray distance optimization should be measured through the experiment to determine, according to the acoustic signal spectrum, choose the best job in the spray distance with higher sound pressure level, more peak frequency doubling, and long continuous working time.