3. Analog modeling: equivalent electrical networks and quadrupoles

3.1 Definitions of equivalent network impedances

Since the main dimensions of the system, apart from its total length, are reduced in comparison with the wavelength, to avoid the appearance of resonances and harmonics at these dimensions, the thermofluidic behavior of a thermoacoustic machine can be modeled using an equivalent electrical network.

Equivalent networks generally comprise capacitances C, inductances L, resistances R ) associated in parallel or series, and equivalent current sources. All these values depend entirely on the geometry of each sub-part and the operating parameters: mean pressure, frequency, etc. When we consider the torque (pressure, volume flow), equivalent to the torque (voltage, current), the definitions of the various impedances...