Experimental evaluation of the acoustic properties of stacked-screen regenerators

The experimental evaluation of the wave number and characteristic impedance of stacked-screen regenerators is described. First, a two-by-two transfer matrix of a stacked-screen regenerator was estimated from pressure measurements performed at four different positions; then, the wave number and characteristic impedance of the regenerator were evaluated using a "capillary-tube-based" theory that models a stacked-screen regenerator as an array of pores having a uniform cross section. The evaluation was applied to seven types of stacked-screen regenerators. The experimental results show that these stacked-screen regenerators can be modeled as arrays of circular-cross-section tubes. Moreover, an empirical equation used to estimate the radius of the circular cross section of the tubes comprising the modeled stacked-screen regenerators was addressed.