Masking armored vehicle infrared signiture (from above)?

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Originally Posted by VariousRen

In terms of thermodynamics, the heat that would be picked up by IR has to go somewhere. If you just vent the engine exhaust below the tank you'll end up with a tank shaped cold spot surrounded by a plume of hot air, instead of a plume of hot air coming out the back of the tank. Probably about the same difficulty to hit with a missile.

The approach then would be to have heat sinks that can store the heat inside the tank, and dump it when it's more convenient (read: when there's not a missile coming towards you). I'm not sure how you would do this, but some thing like disposable metal slugs that you drop (perhaps as IR decoys) would be interesting.

Without running any numbers, I'd wonder about using the engine to refrigerate a liquid when not under threat, and then using it for cooling when you are under threat. Either mixing it with the exhaust or piping or spraying it over the top surface.

Of course, the numbers may be unworkable. And if the liquid is anything fancy, that gives you another load on the logistics guys.