| Self-priming vortex pump is a small flow, high head and low special speed pump, widely used in industrial and agricultural, pharmaceutical and aerospace and other fields.Self-priming vortex pump consists of the impeller, pump body,pump cover,motor and other components. Among them, the influence of the performance and the flow noise of the self-priming vortex pump is related to the two part of the impeller and the pump body. This paper selects a self-priming vortex pump of an enterprise in Zhejiang as the research object.In order to reduce the flow noise, self-priming vortex pump impeller was optimized with the unequal blade spacing distribution.The main research contents are as follows:1.Numerical calculation of steady and unsteady numerical flow field of self-priming vortex pump with CFX. According to the calculation results of the flow field, it is known that when the impeller turns around the tongue, it will cause a great change in the vortex of the impeller and the gap.In the gap between the tongue and the impeller, the velocity and pressure fluctuation amplitude are larger, and the position of the maximum pressure fluctuation amplitude is located near the outlet of the channel.2.Based on the unsteady calculation results, the acoustic field of the self-priming vortex pump is calculated by using the ACTRAN acoustic software. According to the results of acoustics,result was calculated more accurately by using hanning window function and selecting filtering function for the 0.1m.The sound source of the self-priming vortex pump is mainly distributed in the channel and the gap between the tongue and impeller, and the acoustic source is mainly distributed in the space between the tongue and the tongue. The peak acoustic pressure of the inlet and outlet of the pump is at the blade passing frequency and multiple frequency,the acoustic pressure of double blade passing frequency of the pump is maximum. Acoustic wave in the self-priming vortex pump body propagate forward in the plane wave form.3.The impeller of five different blades distribution are designed with unequal spacing blade distribution.Numerical simulation of the flow field and acoustic field of a self-priming vortex pump with five impellers.Numerical results show that: when A ranges from 2°to 6°, blade unevenness has little effect on head and efficiency.When A ranges from 4°to 5°, gap pressure pulsation amplitude in tongue gap decreased a lot, and fluctuation amplitude is no longer concentrated in blade passing frequency and multiple frequency. When A is 4 degree, the noise reduction effect is the best. In the design flow, the noise is decreased by 6dB, and the noise is decreased by 4d B when the low flow is 0.4Qd.4.3D printing method is used to make A=4°impellers samples unequal spacing blade distribution, the performance and noise test. The test results show that: A=4°of unequal pitch blade distribution has little effect on head and efficiency of self-priming vortex pump,, under the design flow, noise decreased by 4dB, and noise decreased by 2dBwhen low flow is 0.4Qd.Self-priming vortex pump was simulated with CFX and ACTRAN.It is analyzed in the self-priming vortex pump that internal flow field and speed pulsation characteristics near the tongue and the horizontal flow passage crossing section, pressure pulsation characteristics in channel wall and tongue gap, sound source distribution, sound pressure frequency characteristic and the acoustic propagation characteristics. In this paper, unequal spacing blade distribution is used to reduce noise of self-priming vortex pump,which provides reference for further noise reduction research. |
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