www.pulse-jets.com

Guys,

I need help to find out what on earth this Thermojet was used for. The origin of the picture is a manual on nuclear proliferation control (!).

No data are given, but the proportions of certain details suggest that the thing is HUGE.

Does anyone have any idea? Does the thing appear as big to you as it does to me?

Bruno

Dear Bruno.
I've seen this jet in a number of documents. I'll locate them and get you the ref's.
What it was used for I don't know.
I think the designer went on to create that sonic pulsejet; the one with all the scoops and bits.
Graham.

Graham,

You are referring to John A. Melenric, the founder/owner of the Thermo-Jet Standard Inc. of Kerrville, Texas. Yes, he is indeed the guy who invented and patented the Thermojet-type engine and its subsequent (increasingly sophisticated) iterations.

What I am interested in is the size of this thing. The thing that hangs from the stand in front is a pair of ear protectors. Those must be, say, 4 inches across, right? If so, the auxiliary exhaust inside diameter must be about 5 in, right? If so, the inner diameter of the main exhaust (before the tail cone) is at least a foot! That's BIG.

Can anyone check those proportions? I am not very good at calculating them from the photo and could be miscalculating teh foreshortening. Maybe someone can do a better job.

A big Thermojet is said to have powered a glider carrying a pilot. If so, I seem to have stumbled upon that one. I wish I knew its thrust, but if it carried a glider and an adult aloft, it was stronger than dog farts. Even a big dog.

Bruno

Correct me if I'm wrong, but the second jet-powered fighter(made by Italy, not the US or the UK, surprisingly) used one...is it the same kind of engine, or is this type a different one? The fighter used a fan driven by an IC engine, which pushed air through the duct into which fuel was sprayed and ignited, boosting thrust...only thing is, it wasn't all that powerful o.O The fuel was an afterburner of sorts, and was used mainly for sprints(like today's afterburners). Other times, the Italian pilots ran on the ducted fan alone, which was decent thrust by itself(900hp engine spinning a fan kinda does that, I guess).

Are we talking about the same engine here? o.O

No, we are not talking about the same engine. Caproni-Campini used what is now commonly called a 'motor-jet'. But, you are right inasmuch as it was indeed called 'thermojet' at the time.

To add to the confusion, after World War II, the term 'thermojet' was officially used by the US military to denote a type of ramjet that used waste heat (not combustion) to generate thrust. It used the so-called Meredith effect. Examples of the thing are radiators on P-51 Mustang and P-38 Lightning fighters and some experimental setups that used exhaust gas from fighter aircraft engines in thrust augmenters.

By now, however,the term refers almost exclusively to Mr. Melenric's curious valveless pulsejets.