Index of content:
Volume 118, Issue 2, August 2005
- NOISE: ITS EFFECTS AND CONTROL 
Time domain computational modeling of viscothermal acoustic propagation in catalytic converter substrates with porous walls118(2005); http://dx.doi.org/10.1121/1.1974759View Description Hide Description
Models for viscothermal effects in catalytic converter substrates are developed for time domain computational methods. The models are suitable for use in one-dimensional approaches for the prediction of exhaust system performance (engine tuning characteristics) and radiated sound levels. Starting with the “low reduced frequency” equations for viscothermal acoustic propagation in capillary tubes, time domain submodels are developed for the frequency-dependent wall friction, frequency-dependent wall heat transfer, and porous wall effects exhibited by catalytic converter substrates. Results from a time domain computational approach employing these submodels are compared to available analytical solutions for the low reduced frequency equations. The computational results are shown to agree well with the analytical solutions for capillary geometries representative of automotive catalytic converter substrates.