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NRL's model of a Rotating Detonation Engine  (Source: nrl.navy.mil)
Currently, the Navy has 129 ships with 430 gas-turbine engines that burn $2 billion of fuel annually

The U.S. Navy is working on new technology for its gas-turbine engines in order to decrease fuel consumption without sacrificing performance.

The answer, according to the Naval Research Laboratory (NRL), is equipping current gas-turbine engines with Rotating Detonation Engine (RDE) technology. These engines could not only efficiently provide propulsion for Navy planes and ships, but also create electricity for an all-electric propulsion system.

The Navy currently uses gas-turbine engines that are based on the Brayton thermodynamic cycle, where air is compressed, combined with fuel, combusted at a constant pressure and expanded. This allows for propulsion or generating electricity, just like the RDEs. However, the Brayton cycle is less efficient than the detonation cycle.

Dr. Kazhikathra Kailasanath, head of NRL's Laboratories for Computational Physics and Fluid Dynamics, noted the following in a 2011 paper for the NRL Review:

The challenge with detonation engines is realizing the efficiency of the detonation cycle. Concepts such as oblique detonation-wave engines have failed to be able to recover the efficiency of this detonation cycle, because much of the energy of the inflow is bound up in kinetic energy, which does not increase the pressure and thus does not improve the efficiency. Pulse detonation engines have taken a different approach by creating an unsteady process that removes the requirement of having high velocity inflow. This creates a whole new set of issues, such as rapid initiation of detonations and the requirement of efficient detonators.

The rotating detonation engine takes a different approach toward realizing the efficiency of the detonation cycle. By allowing the detonation to propagate azimuthally around an annular combustion chamber, the kinetic energy of the inflow can be held to a relatively low value, and thus the RDE can use most of the compression for gains in efficiency, while the flow field matches the steady detonation cycle closely.

Currently, the Navy has 129 ships with 430 gas-turbine engines that burn $2 billion of fuel annually. By equipping engines with RDE technology, power could be increased by 10 percent while fuel consumption would decrease by 25 percent. The Navy could also save $300-$400 million annually.

Source: U.S. Navy



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RE: .
By Vytautas on 11/3/2012 2:35:56 PM , Rating: 5
You are quite ignorant, aren't you? These reactors are at the very core of each ship protected not only by the external armor of the ship, but also several internal steel walls. The reactor itself is or should be in a protective housing which even if the ship was hit directly on the point closest to the reactor wouldn't blow, and as the previous poster explained a sinking ship would prevent the meltdown. Do you think an oil spill has less ecological impact? Or any of the thousands of contaminants common in any ship and specially in warships? Do you even know what radiation actually is? The problem with nuclear power is mainly the ignorance of the common public and as a consequence the fear of the invisible, unknown and not understood. That's why at a certain age not so long ago common wise women or men were burnt on the stake as witches or hexers. One typical example is protesting the building of an atomic power plant because of the terrible "ghost" of radiation danger and being happy about and supporting coal burning powerplants which actually spew radioactive substances (contained previously in the coal) into the air for everyone to breath (the most dangerous form of radioactive contamination). But coal burning is looked at as something simple and commonplace like the fire you use for cooking or at camping. Something that has been with humanity since its' dawn. I'm surprised each day at the lack of common scientific knowledge and common sense in most people. It's unbelievable how some can be so sure about themselves when their almost complete lack of understanding and ignorance about the world and how it works shows clearly in their eyes.


"I'm an Internet expert too. It's all right to wire the industrial zone only, but there are many problems if other regions of the North are wired." -- North Korean Supreme Commander Kim Jong-il

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