Measurements of sound propagation in narrow tubes
The propagation of sound in hollow tubes is a fundamental theme common to many areas of classical acoustics. Kirchhoff’s theory explaining the propagation of sound in a circular tube is now playing an important role as a starting point in studying sound in porous media. This paper reports on measurements of the phase velocity and attenuation coefficient in the narrow regions of tubes, where the sound undergoes anomalous dispersion and is seen to slow down remarkably to the extent that a runner can pass ahead of it. Kirchhoff’s theory can be verified by experiment over a wide range of thermodynamical conditions, from isentropic to isothermal.
Abstract To evaluate the structural integrity for nuclear power piping systems, low cycle fatigue tests were performed on 4 in. diameter carbon steel pipes with flaws. The flaws are local wall thinning, taking into account the minimum wall thickness required for design pressure and circumferentially part-through cracks based on the acceptance standards in the ASME Code Section XI. The applied load was four-point bending with or without an internal pressure under displacement-controlled conditions at ambient temperature. The results show that the flaws above do not influence the integrity of the piping system and pipes do not break within the seismic regime of stress and cycles.