Acoustic attenuation, phase and group velocities in liquid-filled pipes III: Nonaxisymmetric propagation and circumferential modes in lossless conditions

Abstract

Equations for the nonaxisymmetric modes that are axially and circumferentially propagating in a liquid-filled tube with elastic walls surrounded by air/vacuum are presented using exact elasticity theory. Dispersion curves for the axially propagating modes are obtained and verified through comparison with measurements. The resulting theory is applied to the circumferential modes, and the pressures and the stresses in the liquid-filled pipe are calculated under external forced oscillation by an acoustic source. This provides the theoretical foundation for the narrow band acoustic bubble detector that was subsequently deployed at the Target Test Facility (TTF) of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), TN.

Bubble Acoustics From Whales to Other Worlds

“…Therefore after characterizing the bubble-free acoustics of the pipelines 71,72 , a solution was developed 63 . However high-level ORNL budget cuts half way through the contract required a completely different approach, which we also developed 73,74 (based on successful technology we invented for the pottery industry ), and fitted to SNS TTF (Figure 11). The technology was also adapted for outreach 76,77 .…”

Nonlinear control of boundary impedance in an acoustic waveguide

“…At each finite frequency, there exists only a finite number of real-valued modal wavenumbers, which are associated with propagation modes. For the elastic wavetube model, it is shown 46 that three modes propagate at low-frequency, namely two axisymmetric modes (0,1)…”

From research to engagement to translation: words are cheap. Part 2 – a case study

“…the propagation of sound down a curved fluid column, and how horns and cones could facilitate this (discoveries that are used in the device, 3 but published for their ability to allow the sounds of voices and musical instruments on other planets to be simulated, a capability that has since been distributed to planetaria for their Outreach); 31-34 . the acoustic losses in water surrounded by a pressure-release interface (used in the device, 3 but also used to improve maritime safety); 35 . the propagation of sound in bubbly water contained in a vessel that supports coupled modes (used in the device, 3 but also for example, to support safety of the liquid mercury coolant containment system at the world's largest pulsed spallation neutron source, costing US$1.4 billion). 34,[36][37][38][39][40] Premature publication of other aspects of the 'vector' discoveries would have prevented patenting, which was required if the technology was to benefit society: without the protection of a patent, a manufacturer cannot sell the first products at a price that recoups the decade of research and development they paid for before ever any sales income came in, because a competitor (who is not pricing to recoup those R&D costs) can reverse-engineer a product and sell for a lower price. 1 Premature publication therefore can dissuade any industry from making the necessary investment in R&D.…”

“…In 2018, Sloan Water Technology Ltd, a new UK company, was formed, the author's patents being purchased from the University of Southampton. In the 1984-2019 period of research after the original discovery towards direct development of this device, whilst funds were obtained for offshoots of the work (in climate change, 8 nuclear technology 34,[37][38][39][40] etc. ), no RCUK or EU application for funding to support development of the technology 3,21 was ever successful, despite applications in 2018 and 2019 specifically warning of a future pandemic and outlining the need to invest in such technology 3 to make the washing of hands, doorhandles, keypads, Personal Protective Equipment and wounds etc.…”