Dissipative Effects in the Propagation of Linear Waves in Narrow Tubes of Variable Cross Section

Equations are obtained that allow for dissipation during propagation of acoustic wave in narrow tubes of variable cross section. The wave transmission coefficient through the tube of a special design is calculated by two methods. It is shown that when viscosity in tubes of variable cross section is taken into account, the continuity equation should be used as the equation of connection between pressure and vibrational speed.