Park K.C.,University of Colorado at Boulder |
Park K.C.,KAIST |
Lim S.J.,Ocean Aero |
Huh H.,Ocean Aero
International Journal for Numerical Methods in Engineering | Year: 2012
An explicit integration algorithm for computations of discontinuous wave propagation in heterogeneous solids is presented, which is aimed at minimizing spurious oscillations when the wave fronts pass through several zones of different wave speeds. The essence of the present method is a combination of two wave capturing characteristics: a new integration formula that is obtained by pushforward-pullback operations in time designed to filter post-shock oscillations, and the central difference method that intrinsically filters front-shock oscillations. It is shown that a judicious combination of these two characteristics substantially reduces both spurious front-shock and post-shock oscillations. The performance of the new method is demonstrated as applied to wave propagation through a uniform bar with varying courant numbers, then to heterogeneous bars. © 2012 John Wiley & Sons, Ltd.
Kim G.-T.,Ocean Aero |
Gim S.-J.,Korea Advanced Institute of Science and Technology |
Cho S.-M.,Samsung |
Koratkar N.,Rensselaer Polytechnic Institute |
Oh I.-K.,Ocean Aero
Advanced Materials | Year: 2014
Wetting-transparent graphene films grown in situ by chemical vapor deposition on hydrophobic (roughened) copper surfaces offer excellent resistance to copper corrosion while maintaining the intrinsic hydrophobicity of the surface, enabling superior performance for water-harvesting applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Mahmoudian N.,Ocean Aero |
Geisbert J.,U.S. Navy |
Woolsey C.,Ocean Aero
IEEE Journal of Oceanic Engineering | Year: 2010
This paper describes analysis of steady motions for underwater gliders, a type of highly efficient underwater vehicle which uses gravity for propulsion. Underwater gliders are winged underwater vehicles which locomote by modulating their buoyancy and their attitude. Several underwater gliders have been developed and have proven their worth as efficient long-distance, long-duration ocean sampling platforms. Underwater gliders are so efficient because they spend much of their flight time in stable, steady motion. Wings-level gliding flight for underwater gliders has been well studied, but analysis of steady turning flight is more subtle. This paper presents an approximate analytical expression for steady turning motion for a realistic underwater glider model. The problem is formulated in terms of regular perturbation theory, with the vehicle turn rate as the perturbation parameter. The resulting solution exhibits a special structure that suggests an efficient approach to motion control as well as a planning strategy for energy efficient paths. © 2005 IEEE.
Philen M.,Virginia Polytechnic Institute and State University |
Philen M.,Ocean Aero
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
Variable stiffness fluidic flexible matrix composites (f 2mc) are investigated for vibration isolation through analysis and experiments. The fluidic flexible matrix composites are novel structures that have been shown to achieve significant changes in stiffness through simple valve control. The objective of this research is to develop analysis tools to investigate the f 2mc variable modulus system for semi-active vibration isolation and to validate the results through experiment. A nonlinear analytical model of an isolation mount based on the f2mc tube with a proportional valve is developed. Analysis results indicate that the f 2mc based isolation mount is effective for reducing the force transmitted to the foundation. Simulation studies demonstrate that the transmissibility ratio can be tuned via a proportional valve, where the resonant frequencies and damping can be regulated. Experimental results agree with analysis results and validate semi-active vibration isolation using a proportional valve. © 2011 SPIE.
Sunny M.R.,Aliah University |
Kapania R.K.,Ocean Aero
International Journal of Computational Methods in Engineering Science and Mechanics | Year: 2014
We have developed an artificial-neural-network-based identification scheme for a modified version of the Preisach model for the hysteresis and relaxation observed in the variation of electrical resistance with strain in conductive polymer nanocomposites. This modeling approach models hysteresis and relaxation as two independent phenomenons. At first, the effects of the relaxation and static hysteresis have been decoupled from the total value of the resistance at different time steps. Unknown parameters in the relaxation model have been identified using a global optimization scheme. Identification of the static hysteresis has been done using an artificial neural network. © 2014 Copyright Taylor and Francis Group, LLC.
Ocean Aero | Date: 2014-07-29
A submersible vessel having wing and keel assemblies that are extendable for wind-powered surface operation and retractable to reduce drag for submerged operation or to place the vessel in a more compact configuration. A deployment mechanism including an actuator and linkage pivots the wing and keel assemblies simultaneously between the deployed and retracted configuration. The vessel may have first and second pressure hulls flanking the wing and keel assemblies. A drive mechanism including a motor and a gear train employing pulley-and-cable assemblies rotates either the wing and flap together such that the flap angle relative to the wing is constant, or to change the flap angle relative to the wing with the wing angle of incidence held constant. The invention also provides a retractable wind-powered propulsion apparatus that is mountable to the hull assembly of a submersible or non-submersible vessel.
Ocean Aero | Date: 2016-05-17
News Article | September 28, 2016
In a three-day US Naval exercise that took place last month in Rhode Island's Narragansett Bay, Lockheed Martin achieved a world-first. It used an unmanned submersible to launch an unmanned aerial vehicle (UAV), while an unmanned surface vehicle provided surface reconnaissance and surveillance. The exercise began with Ocean Aero's Submaran surface vehicle relaying instructions from a ground control station to Lockheed Martin's Marlin MK2 autonomous underwater vehicle, via underwater acoustic communications. Acting on those instructions, the Marlin in turn released a canister containing the company's fixed-wing Vector Hawk UAV, with its wings folded back. Upon reaching the surface, that canister opened and the UAV unfolded its wings and took off, proceeding to follow a predetermined flight path. Propelled by either an electric thruster or a retractable wingsail, the 4.14-meter (13.6-ft) Submaran (seen below) is equipped with solar panels that allow it to remain operational for months at a time. It can be outfitted with a variety of sensors for different applications, and is even capable of submerging beneath the surface. The 10-ft (3-m) battery-powered Marlin can descend to up to 1,000 ft (305 m), cruising for up to 24 hours and managing a maximum payload of 250 lb (113 kg). The Vector Hawk, meanwhile, can remain airborne for over 70 minutes on one charge of its battery pack, and has a line-of-sight range of up to 15 km (9 miles).
News Article | July 2, 2015
THOUSAND OAKS, Calif.--(BUSINESS WIRE)--Teledyne Technologies Incorporated (NYSE:TDY) announced today that it has invested additional capital and increased its ownership interest in Ocean Aero, Inc. to approximately 37 percent. Based in San Diego, California, Ocean Aero is designing unmanned surface vehicles that will also have the ability to descend subsea. Terms of the transaction were not disclosed. Unlike traditional unmanned surface vehicles or autonomous underwater vehicles (AUVs), Ocean Aero is designing unmanned underwater and surface vessels (UUSVs) capable of operating in both surface and sub-surface environments. UUSVs would provide a unique set of capabilities to the scientific, defense, and oil and gas communities. For example, such vehicles would have efficient propulsion and communication while on the surface, and the ability to dive, allowing water column analysis, stealth and hazardous weather avoidance. “The additional investment in Ocean Aero demonstrates our confidence in Ocean Aero’s technology and leadership,” said Robert Mehrabian, Chairman, President and Chief Executive Officer of Teledyne. “Ocean Aero’s planned UUSVs complement Teledyne’s broad portfolio of unmanned marine systems, including Gavia AUVs, SeaBotix remotely operated vehicles, and our market-leading autonomous gliding vehicles.” Teledyne Technologies is a leading provider of sophisticated instrumentation, digital imaging products and software, aerospace and defense electronics, and engineered systems. Teledyne Technologies’ operations are primarily located in the United States, Canada, the United Kingdom, and Western and Northern Europe. For more information, visit Teledyne Technologies’ website at www.teledyne.com. This press release contains forward-looking statements, as defined in the Private Securities Litigation Reform Act of 1995, relating to a recent investment. Actual results could differ materially from these forward-looking statements. Many factors, including the ability to design products and achieve anticipated growth, as well as market and economic conditions beyond either company’s control, could change anticipated results.