Underwater acoustic measurements with the Liberdade/X-Ray flying wing glider

Abstract

An underwater glider based on a flying wing design (Jenkins et al., 2003) presently is under development by the Marine Physical Laboratory, Scripps Institution of Oceanography and the Applied Physics Laboratory, University of Washington. This design maximizes the horizontal distance between changes in buoyancy to minimize mechanical power consumed in horizontal transport. The prototype wing has a 6.1 m wing span and is 20 times larger by volume than existing gliders. Initial at-sea tests indicate that the lift-to-drag ratio is 17/1 at a horizontal speed of about 1.8 m/s for a 38-liter buoyancy engine. Beamforming results using recordings of the radiated noise from the deployment ship by two hydrophones mounted on the wing verify aspects of the prototype wing flight characteristics. The payload on the new glider will include a low-power, 32-element hydrophone array placed along the leading edge of the wing for large physical aperture at midfrequencies (above 1 kHz) and a 4-component vector sensor. Data previously collected by these types of arrays illustrate the performance of narrow-band detection and localization algorithms. Flight behaviors are being developed to maximize the arrays’ detection and localization capabilities. [Work sponsored by the Office of Naval Research.]

Tools to Compare Diving-Animal Kinematics with Acoustic Behavior and Exposure

“…Bioacoustic Probes have found applications beyond attachment to wildlife. Dr. Thode used them as independent elements comprising a portable acoustic array (Thode et al, 2006) and as convenient selfcontained tilt-meters for conventional acoustic arrays; Thode and Dr. Gerald D'Spain of Scripps used them as acoustic and attitude sensors during prototype trials of the Liberdade X-Ray underwater glider (D'Spain et al, 2005); and Dr. Jim Miller of the University of Rhode Island obtained a B-Probe for use inside an autonomous underwater vehicle. Bioacoustic Probes have been employed as simple seafloor recorders in several studies, including a behavioral study of beluga-whale habitat usage (Burgess et al, 2005), a geoacoustic study of sediment properties (Tang, 2005), and geophysical studies of bubble seeps (Leifer and Tang, 2006) and geothermal vents (Chadwick et al, 2008).…”

Tools to Compare Diving-Animal Kinematics With Acoustic Behavior and Exposure

“…Bioacoustic Probes have found applications beyond attachment to wildlife. Dr. Thode used them as independent elements comprising a portable acoustic array (Thode et al, 2006) and as convenient selfcontained tilt-meters for conventional acoustic arrays; Thode and Dr. Gerald D'Spain of Scripps used them as acoustic and attitude sensors during prototype trials of the Liberdade X-Ray underwater glider (D'Spain et al, 2005); and Dr. Jim Miller of the University of Rhode Island obtained a B-Probe for use inside an autonomous underwater vehicle. Bioacoustic Probes have been employed as simple low-cost seafloor recorders in several studies, including a behavioral study of beluga-whale habitat usage (Burgess et al, 2005), a geoacoustic study of sediment properties (Tang, 2005), and geophysical studies of bubble seeps (Leifer and Tang, 2006) and geothermal vents (Chadwick et al, 2008).…”

Winglet effect on hydrodynamic performance and trajectory of a blended-wing-body underwater glider

“…Moreno et al (Ayuso Moreno et al, 2006) compared the BWB configuration with conventional ones and pointed out the superior hydrodynamic performance of BWB. For underwater gliders, researchers from ONR adopted the BWB layout firstly and carried out the Liberdade class underwater glider (D'Spain et al, 2005). Sun et al (Sun et al, 2015) optimized the shape of a blended-wing-body underwater glider (BWBUG) to a longer sailing range and higher lift-to-drag ratio.…”