A time domain model of a resonance tube containing a porous ceramic material

Paper in proceeding, 2007

Modeling the acoustic field in capillary tubes in in porous ceramic materials using a finite difference scheme requires a very fine mesh. Describing a complete acoustic system, such as a porous ceramic material inside a resonance tube, demands a large mesh and a long calculation time. One way to overcome this is by combining a finite difference scheme with a faster method for the acoustic field in the simpler parts of the tube. For this purpose a time domain model of a porous ceramic material in a resonance tube is under development using a combination of the Equivalent Source Method (ESM) and the Finite Difference Time Domain (FDTD) method. The porous ceramic material is described, including viscous effects, by the FDTD method and the resonance tube is described by the faster and simpler ESM. This combination of ESM and FDTD will be used to model a standing wave thermoacoustic refrigerator, which basically consists of a loudspeaker, resonance tube, stack (e.g. porous ceramic material) and heat exchangers.