Are you saying that you've developed a scramjet that can operate from 0-10,000 kph -- because I know that existing scramjet technology is far from achieving this, despite the best efforts of many highly skilled researchers.

The design of an engine that will produce a usable amount of thrust at 0kph is *lots* different to one that will do the same at 10,000 kph and, as someone who's spent a *lot* of time, effort and money researching and designing jet engines, I would have to say that if you've been able to come up with such a beast in a garage then you're doing very well indeed.

However, if you just have an "idea" then be warned that there's an awfully big void between that "idea" and the creatin of a working engine.

I've lost track of the number of good ideas I've had that either turned out to have already been "discovered" by others or which ultimately turned out to be dead ends -- which probably means that they were also already "discovered" by others who also found out that they didn't work.

It's taken me around a quarter of a million dollars to produce a new type fo valveless pulsejet engine that has *no* moving parts and simply equals the efficiency of a pure turbojet and is strictly a subsonic power-plant. I shudder to think of the costs, time, resources and efforts that would be required to produce and test even the most basic scramjet.

I made a very deliberate decision not to try and compete head-on with the well-funded educational or military research programs that are working on exotic designs such as scramjets and PDEs -- I'm simply not well educated enough, well funded enough, or well resourced enough to even consider such folly.

Instead, I focused on a very narrow objective that also coincides with a very active and rapidly growing market -- the design of an ultra-low-cost jet engine of 50-150lbs thrust (more if clustered) with a TSFC of around 0.9-1.0 for use on UAVs or RPVs.

The result is a 21st-century pulsejet engine that runs cool enough to be mounted internally (you can actually place your hand on it while it's running), matches a resonably efficient turbojet in terms of fuel-efficiency, has a reasonable power/volume ratio and an exceptional power/weight ratio, is virtually immune to FOD, runs on a wide range of fuels, and costs just 1/10th the price of an equivalent gas-turbine design.

It's not an engine that will ever power a commercial passenger jet and it still has numerous downsides compared to turbojets: it's noisy, it vibrates, it has a limited life-time (due to vibration and rapid thermal cycling), it is only useful for subsonic flight (up to about 0.85M) and its efficiency is lower than a modern turbofan.

However, by setting ones sights on a more achievable target, it's much easier to get a bullseye.

And, surprisingly enough, the market is still huge. The Economist published a story earlier this month which suggested that the US military sector of the UAV market alone would be worth many billions of dollars by 2010.

No doubt the immediate question that springs to mind in this forum is "can it be used for model airplanes?" to which the answer is:

* yes, if you don't mind a noise level of 135dB :-(
* yes, if you can use 50lbs of thrust

Unfortunately, the minimum size at which the engine will operate efficiently is limited by the Reynolds numbers associated with some internal gasflows so 50lbs-thrust is about the smallest that this engine can be made. Any smaller and it simply runs like a regular pulsejet -- ie: very inefficiently and very hot.