Calculated and experimental method for determination of acoustical impedances of pipe systems elastic elements

In engineering practice the means of noise control for liquid path of hydraulic and air pipelines (flexible insertions, hoses, bellows and etc.) are characterized by acoustic impedance. By definition it is the relation of sound pressure at the input and output of the element to the velocity at the input when velocity at the output is equal to 0. These parameters are sufficient for the description of transfer properties of an actual elastic element and are necessary for calculation. It is impossible as a rule to calculate these parameters. For the most part they are determined experimentally. Calculated and experimental method, which allows to simplify procedure of acoustic impedance determination and to use experimental results in analysis, is considered. The elastic element is represented as a cascade connection of quadrupoles, which are equivalent to elastic and rigid parts of elastic element. The elastic part parameters (sound speed and loss factor) are determined from extremum of the absolute value of relation of sound pressure to velocity at the measuring chamber input. The other parameters are calculated.