DESIGN PARAMETERS OF FREE-FLOODING CYLINDRICAL TRANSDUCERS
Abstract
The free-flooding cylindrical transducer devoid of pressure-release material combines resistance to hydrostatic pressure with design flexibility resulting from the existence of resonances primarily controlled by two independent dimensions: the radius, which controls the structural (ring) resonance, and the axial length which determines the acoustic ('squirter') resonance. Values of radiation impedance generated for a squirter of vanishing wall thickness from an integral equation formulation of the free-flooding cylinder of finite length, were used to compute curves of dimensionless natural frequency vs. squirter aspect ratio (ratio of length to diameter) and of motional conductance vs. dimensionless frequency. It is concluded that (a) squirters of small aspect ratio are undesirable, (b) squirters of medium and large aspect ratio can combine wide bandwidths with substantial conductance levels; (c) squirters with large aspect ratios should have in vacuo natural frequencies substantially lower than generally obtained with transducer materials; the natural frequency can be lowered to the desired value by attaching axially oriented inertia wedges to the squirter; (d) near-coincidence of the acoustical (squirter) resonance with the structural (ring) resonance can produce an exceptionally wide bandwidth for squirters of large aspect ratio provided the slopes of the transducer and radiation reactance mutually compensate near the in vacuo natural frequency, thus producing a frequency range of near-resonant condition. An equation is derived which the transducer parameters must satisfy to produce this condition.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1969
- Accession Number
- AD0685278
Entities
People
- Miguel C. Junger