Acoustic analysis and optimal design of bladder attenuator array for fluid-borne noise reduction in variable pressure fluid systems

Fluid-borne noise induced by pumps’ flow ripples leads to pipe vibrations and lowers the reliability of system components in the fluid system. The bladder attenuator has been proposed to suppress flow ripples due to its advantages of the compact design and broadband frequency attenuation. However, the working pressure range of the bladder attenuator is limited, and the attenuator’s optimization with fluid system is also needed. In this paper, the acoustic model of bladder attenuator considering the wave propagation is firstly proposed. And an attenuator array with different charge pressures is proposed to cover a wider pressure range for variable pressure systems. Since the charge pressure affects the attenuation performance and working pressure range, it is difficult to achieve the best performance manually. To address this, an optimization method for the attenuator array is proposed. Three experiments: frequency sweep test, typical working status test, and varying pressure test are carried out to validate the acoustic model and the optimization method. The frequency sweep test validates the accuracy of the acoustic model for a single attenuator and an attenuator array. The typical working status test obtains optimal charge pressures for the attenuator array. In the varying pressure test, the attenuator array achieves the average reduction ratio of 75.4 % at 100 Hz, 84.4 % at 300 Hz, and 91.9 % at 500 Hz, indicating the effectiveness of the optimization method.