The Reflection of Sound due to a Change in Cross Section of a Circular Tube

The reflection and transmission coefficients due to a change in cross section of a circular tube are determined by calculating the exact pressure distribution in the vicinity of the discontinuity. The fluid medium in the tube is assumed to be ideal in the sense that the pressure distribution satisfies the wave equation. In contrast to the simpler theory which assumes a tube which is small compared to the wave‐length, the following theory is subjected only to the assumption of an ideal fluid.