Abstract:Taking the deflector of a vertical sprinkler as a study model, the driving force applied on the deflector by the water jet is analyzed and measured. Based on the fluid-structure interaction principle, a numerical model for describing the driving force is built initially and validated by the experimental results. The fluid pressure profile obtained from a flow field simulation is imposed onto the deflector, then solid mechanics and free vibration analyses are carried out on it. The results show that the maximum error in the horizontal and vertical components of the driving force between simulation and experiment is 15.98%, which reduces with the increasing pressure. The maximum deformation is mainly distributed in the much curved part of the deflector. Eventually, the 1st through 6th order natural frequencies and corresponding vibration modes are obtained. When the deflector works under the frequency of less than 122.6 Hz, its vibration mode is usually in the first order. In order to improve the stability and reliability of the deflector in operation, its local configuration may need to be redesigned or a material with even stronger strength is adopted.
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