Juliet Marine Systems: Ghost |
In a press release from January 10th, 2012, Juliet Marine Systems Inc.(Porthmouth NH, USA) "announced plans to select a weapons
integrator for its revolutionary new product, GHOST. GHOST is a high-speed attack craft specifically designed .... to counter
threats such as piracy ...It uses supercavitation technology and high-performance jet engines to achieve hull friction reduction
and high speed (60 mph)."
According to further press release the company announces the soon-to-be-designed 150-foot ship promise to evade radar.
The vessel will be capable of sinking nuclear submarines and large surface vessels. Its large fuel capacity allows for long
duration missions.
Assumptions: The Ghost is best described as a three hull catamaran with movable extention plates and jet engines in the outer hulls. A maximum weight of 10 000 kg is assumed. The necessary buoyance is allocated on the central hull (20%) and extension plates with adherend outer hulls (80%).
Central hull:
Outer hulls Resistance
Resistance of the catamaran during cavitational running is composed of resistance of the outer hulls and extention plates while
resistance of the central hull is neglected because it is out of water.
By lowering the extension plates the running depth at maximum speed may be raised to estimated 3 m. This results in assumed large resistance of the extension plates, which obviosly are also performed to run supercavitational since openings for gas exit in the vicinity of the front region of extenion plates are visible. Power Unit The vessel uses jet engines as power units. Jet engines driven by gas turbines are advantegeous because of their low weight/power-ratio (ca. 0,27 kg/kW), high-performance and large exhaust gas volume, what is especially advantegeous in the time of accelleration to supercavitation movement. Taking into account the denounced velocity and the assumed resistance of 50,000 N an engine power of 1600 kW is necessary. Gas turbines in this region are industrial available and can be installed concerning weight and dimensions within the outer hulls. |