# Numerical and Experimental Analysis of Pressure Pulsation Attenuator Based on Helmholtz Resonator
###### Abstract  
Due to the development of aviation hydraulic systems towards high pressure and high flow, the frequency range of pressure pulsation becomes wider, and the amplitude of pulsation increases. This puts higher requirements on the attenuation characteristics of the pressure pulsation attenuator. To reduce the damage caused by pressure pulsation to the pipeline, a Helmholtz-type pulsation attenuator (HTFA) is designed, which works through the Helmholtz resonant chamber. The theoretical model of HTFA is established by the method of lumped parameter method and distribution parametric method. The insertion loss is adopted to evaluate its attenuation characteristics. The internal pressure dynamic characteristics and attenuation effect of the HTPA are analyzed by simulation and experimentation. The results show that the pulsation attenuation rate \(\delta\) was 40% after the installation of the attenuator. In the frequency range of 0-1000 Hz, the maximum insertion loss is 19 dB, which verifies the validity and correctness of the theoretical model. pressure pulsation; insertion loss; attenuation characteristics; Helmholtz resonant chamber 2023138381. 13 June 2023138381. 13 June 2023138381.  
or installing a pressure pulsation attenuator. Pressure pulsation attenuators are mostly installed in hydraulic system circuits. In 1981, [PERSON] [4] used an acoustic Helmholtz resonator to design an effective pressure pulsation attenuator, which was installed at the pump outlet to eliminate pressure pulsation. [PERSON] et al. [5] improved the H-type pulsation attenuator. He replaced the liquid column in the neck with a high density of metal mass and the liquid in the cavity with a low volume elastic coefficient of gas. The attenuation effect in the frequency range near the resonant frequency was improved. [PERSON] [6] used multiple parallel spherical high-pass acoustic filters to suppress or eliminate pressure pulsation in the low-frequency range. Experimental results show that the amplitude of 60 Hz pressure pulsation is reduced by 90%. Johannes Kepler University Linz [7] designed a compact pressure pulsation attenuator. The pressure pulsation attenuator can effectively eliminate the pressure pulsation within 200 Hz, and the attenuation effect is best at 140 Hz. [PERSON] et al. [8] used two Helmholtz resonators to control each of the two unstable modes in the combustion chamber system. By controlling the area of the Helmholtz resonator neck region, the resonant frequency of the Helmholtz resonator was changed. The two unstable modes in the combustion chamber system were eliminated. In addition, [PERSON] and [PERSON] et al. [9] used two Helmholtz resonators in parallel and considered the effect of different geometries (cylindrical, rectangular) on the noise damping performance. Compared to the rectangular resonator, the cylindrical resonator reduces the sound pressure level by approximately 12 dB and has greater transmission loss. [PERSON] [10] designed a compact pressure pulsation attenuator by adding a compliant voided urethane lining to the inner wall of the Helmholtz resonator. At the same resonant frequency, the size of the attenuator can be greatly reduced by adding the lining. [PERSON] [11] developed a compound pressure pulsation attenuator by adding a piston and spring to a Helmholtz resonator. It has the advantages of fast response and small volume and can be integrated into the hydraulic pump. In 2013, [PERSON]. [12] focused on the three-stage series H-type pulsation attenuator. The relationship between design parameters and attenuation characteristics is analyzed and used in the initial design of a three-stage series pulsation attenuator. Based on the Helmholtz resonator, he developed a hemisphere-type pulsation attenuator [13], set up its lumped parameter model, distributed parameter model, and step section approximation model, respectively. There is little difference between the resonant frequencies of these three models, and the distributed parameter model is more consistent with the experimental results.