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December 2012 Issue

DCNS Shows Off New Submarine Technologies
DCNS (Paris, France) unveiled in October an anti-aircraft system for submarines, as well as its new concept ship SMX 26, a small submarine designed for operation in waters less than 15 meters deep and littoral zones not usually accessible for conventional submarine operations.

Developed by DCNS and MBDA (Paris), the anti-aircraft system is available in two versions: mast-mounted and self-defense. The mast-mounted system, comprising a retractable mast supporting a turret containing several Mistral short-range missiles, is designed to be incorporated into the fin of a submarine. The self-defense system deploys a UUV, inside of which is a Mica medium-range missile, from a torpedo tube.

The SMX 26 can remain on the seabed for long periods, monitoring its environment, before attacking its target. It will be capable of landing quickly on all types of seabed using an extendable wheeled undercarriage system.


US Navy’s First MLP Ship Floated from Dry Dock
The U.S. Military Sealift Command’s (MSC) first Mobile Landing Platform (MLP) ship completed in November its first float out operation at the General Dynamics NASSCO (San Diego, California) shipyard in San Diego.

Designated T-MLP-1, the ship will be named USNS Montford Point. The first of three MLPs planned for construction at NASSCO, it is scheduled to be delivered to MSC in May. The MLP will join MSC’s Maritime Prepositioning Force. These ships, the centerpiece of the Navy’s “sea base” concept, will provide the capability to transfer vehicles and equipment at sea.


Eco Marine Designs EnergySail Array for Naval Ships
Eco Marine Power Co. Ltd., based in Fukuoka, Japan, released in November details of its modified version of the Aquarius MRE System for use on naval and coast guard ships. This modified system will use Eco Marine’s EnergySail technology to form an array of devices able to harness renewable energy on these types of ships.

A naval frigate could have up to four EnergySail’s incorporated into its design. Smaller patrol vessels and coast guard ships could be fitted with two of the devices.

A control system, which is undergoing tests in cooperation with KEI System Ltd. (Osaka, Japan), will automatically raise, lower and position each EnergySail in accordance with prevailing weather conditions. Each EnergySail will be capable of performing as a rigid sail.


OceanWorks International Recertified for Navy Work
OceanWorks International (Burnaby, Canada) has been reauthorized by the U.S. Navy’s Naval Sea Systems Command Note 5000 to perform Deep Submergence Systems Scope of Certification work in support of designated submarine rescue and intervention systems. This renews the existing Note 5000 that OceanWorks held since September 2011.

OceanWorks International is one of eight civilian and 14 government and military organizations in the world that have received this authorization. The company received the highest level of compliance for each section audited.


Navy Oceanographers Improve Wave Forecasts
U.S. Naval Research Laboratory (NRL) physicists are working to improve forecasts of ocean conditions and sea states by developing a means to include the effects of the amorphous near-surface phenomenon of turbulence generation by nonbreaking waves.

The parameterization of turbulence production in the upper ocean has primarily relied on the assumptions of wall turbulence, where the wind-generated surface friction velocity acts as a moving boundary. In the top few meters of the ocean, another source term is added due to turbulence injection by breaking waves.

Theories and hypotheses have attempted to describe a third mechanism, which would account for energy flux from nonbreaking waves to the upper ocean turbulence, but empirical results have struggled to establish its existence.

The researchers measured turbulent velocities at the water surface in a laboratory wave tank using the thermal-marking velocimetry technique. Numerically, a nonlinear model for the wave motion was coupled with Large Eddy Simulation for the turbulent motion. Both numerical and lab results confirmed the turbulence production due to wave motion, and the turbulent kinetic energy was found to be a function of time, wave steepness, wave phase and initial conditions.

Unlike present wave dissipation formulations, which primarily rely on wave spectrum information, this new mechanism reveals a function of existing turbulence in the upper ocean. This imposes a feedback requirement between ocean circulation and surface wave models and further reveals the added need to couple atmosphere-wave-ocean dynamics within a joint forecasting system.


2013:  JAN | FEB | MARCH | APRIL | MAY | JUNE | JULY | AUG | SEPT | OCT | NOV | DEC
2012:  JAN | FEB | MARCH | APRIL | MAY | JUNE | JULY | AUG | SEPT | OCT | NOV | DEC

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