here is something interesting http://phoenixnavigation.com/mainmenu.htm

A bumdled set of high priced unproven experimental toys that'll extract more money than energy.

Pulse detonation has great promise in some applications. As a primary propulsive engine in a general aviation aircraft is not one of them. We already have enough trouble with noise complaints. A pulse detonation engine is a remarkable means of turning fuel into noise.

On the other hand, the technology may offer a means of increasing the overall efficiency of more conventional engines via incorporation in the combustion systems.

The site as a whole appears to be somebody's collection of wild ideas. Most are not particularly original or promising.