Author: Martin Su
Date: 06-14-12 03:19
I appreciate your effort Lars. However, the brief PDF file has no real citations. At the end, there are four references to "simulations" and "modeling" from 1998.
With all due respect, I give most of the weight to real-world ships and proven ideas. The short paper deals with some totally unproven concepts. I have never heard of a real-world ship with massively reduced acoustic or infrared signature.
I will explain why no known acoustic or infrared signature reduction has ever been shown in the last 40 years to my knowledge. The purpose of a surface ship is to remain above-water and use its radar and interceptor missiles to defend the airspace (to protect a carrier).
By nature, a surface ship must be moved quickly with propellers. You can come up with laboratory ideas for toy-sized model ships that might reduce the propeller signature.
However, in the real world, it is impossible to significantly reduce the acoustical energy caused by the spinning of propellers to move a 10,000 to 15,000 ship at 30 knots. It doesn't exist.
Similarly, the purpose of 78-MegaWatt engines is to maintain high temperatures and high pressures to drive the massive shaft that spins the gigantic propellers.
You seem to misunderstand the source of the infrared signature. It comes from the 78-MegaWatt engines. The primary infrared source is not the waste heat. The waste heat is a secondary source.
You might be able to reduce the waste heat to a limited extent. However, the idea of significant reduction of the waste heat generated by a destroyer has never been shown. "Modeling" and "simulation" are only unproven ideas. They don't mean anything unless you can prove real-world relevance, which has not happened.
The goal is not to reduce the engine temperature. If you do that, the efficiency and power generated by the engines will fall dramatically.
Anyway, I did enjoy your PDF file on waste heat reduction. However, I remain unconvinced. That ivory-tower academician has never tried to completely mask 78-megawatts of power. He has some heat-attenuation ideas, but their effectiveness remains unproven.
I have my own heat reduction ideas, but they are unworkable on a destroyer. For example, I would extend a long pipe (shaped hydrodynamically) deep into the cold water layers to dissipate the heat. However, the ship would become absurdly massive and have unusable fuel mileage.
The problem isn't the idea of heat dissipation. I could easily come up with heat vanes suitable for a water environment. The problem is scale and impairing the functionality of a destroyer. Dissipating 78-MegaWatts of power beyond the discrimination of modern infrared detectors is almost impossible (e.g. one-degree difference can be detected).
Also, adding all of these theoretical massive contraptions onto a 10,000+ ton ship would burden the destroyer with the mobility of an oil platform.
In summary, there is a plethora of heat dissipation ideas. To my knowledge, no known large capital ship has ever been built with true infrared or acoustical stealth. If you can't provide real-world examples to the contrary, I'm afraid I will continue to claim no significant infrared or acoustical stealth for real-world military capital ships.
By the way, you have not addressed the problem of infrared signatures caused by the launch plume of missiles and the firing of the main gun on the DDG-1000. Whether it's infrared from the DDG-1000, missile launch plume, or firing of the main gun, the DDG-1000 should be easily detectable with infrared sensors.
This is my last reply on this topic, because I think I've said everything that I wanted to say.