Jet + steam for boat

[syler]

So you have a jet motor that produces gobs of heat and an endless supply of water. Is there any possible way it doesn't make sense to use the water to cool the motor and do so in a way as to get thrust from the steam? I'm thinking keep it simple and just construct a jacket around the after burner. Then just mist water onto it. To get really fancy, it could join the main thrust in the rear in a cone.

This is one of those things that seems so obvious that there must be something wrong with the idea or everyone would be doing it.

[racket]

Hi Syler

We don't want to cool our engines , they're heat engines , and the hotter they run the better , we want them to be within a few degrees of "danger point" .

Water needs massive amounts of energy to turn it into steam ( phase change, latent heat of evaporation) , then more energy to pressurise things so that velocity can be achieved , you'd be only looking at a few percent increase in thrust , not worth the complication of constructing water jackets .

Cheers
John

[metiz]

Might be a mute point, but why would you want to put a jet engine (for thrust, that is) on a boat? That has to be one of the least efficient means of locomotion ever