Search found 16 matches

by Glenn Olson
Wed Mar 04, 2009 4:50 am
Forum: Ramjet forum
Topic: Web Site for Alt-Accel Shutting Down
Replies: 7
Views: 5722

Web Site for Alt-Accel Shutting Down

Notice: Due to economic concerns and my more pressing activities in other areas I will be shutting down my Alt-Accel web site on or about April 15, 2009. Anyone wishing to copy that material may do so freely, though the ideas I've created remain mine and I would appreciate the credit. My e-mail addr...
by Glenn Olson
Mon Dec 17, 2007 5:44 am
Forum: Ramjet forum
Topic: how to use RJSC?
Replies: 4
Views: 3638

I received RJSC as is, with no documentation. As I recall it was written for college engineers who already knew what everything was. When I posted it I didn't think to write up any documentation, though I think I was in a hurry at the time. Anyway, here are a few quick notes. 1. I really don't recal...
by Glenn Olson
Mon Dec 17, 2007 5:01 am
Forum: Ramjet forum
Topic: air requirements for a large subsonic ramjet
Replies: 8
Views: 5942

Testing ramjets is difficult. One way, of course, is to stick them on the end of a rotor. This can be a serious problem if it goes too fast or becomes unstable and breaks up at high speed. Rotary Rocket tested theirs in a pit. They can also be tested in a cage. My idea was to wrap several layers of ...
by Glenn Olson
Tue Feb 06, 2007 3:42 am
Forum: Ramjet forum
Topic: Designing for a particular speed
Replies: 11
Views: 9801

Don, I believe your question was not answered in full so I'll give it a try. First, I suggest you take the time to review my web material at http://www.alt-accel.com/arla/3m-arla.htm and http://www.alt-accel.com/ramjet2.htm. I spent a couple thousand hours on research and writing and prefer not to r...
by Glenn Olson
Tue Feb 06, 2007 12:19 am
Forum: Ramjet forum
Topic: Continuous detonation ramjet, is it possible?
Replies: 6
Views: 7206

For a ramjet (not scramjet) continuous detonation would not be possible because in detonation, as has been stated, the flame front travels faster than the speed of sound. In a subsonic air flow this means that the flame front would travel to the fuel supply then extinguish or revert to combustion. Y...
by Glenn Olson
Wed Oct 25, 2006 3:28 am
Forum: Ramjet forum
Topic: General Ramjet Info Please
Replies: 33
Views: 20028

re: General Ramjet Info Please

I suggest you also look at http://www.alt-accel.com/ramjet2.htm then read http://www.alt-accel.com/arla/3m-arla.htm, including the references and Back Pages. Some of the material is a bit dated but still has some useful information on ramjets. The other folks have more recent experience as well as o...
by Glenn Olson
Thu Jun 23, 2005 10:43 pm
Forum: Ramjet forum
Topic: Characteristic Flame Length
Replies: 1
Views: 2611

Characteristic Flame Length

Does anyone have any good references on characteristic flame length, preferably on the internet? I would like to know more about estimating combustion chamber lengths but my searches of the web have not been fruitful.

Glenn
by Glenn Olson
Wed Jun 22, 2005 5:52 pm
Forum: Ramjet forum
Topic: Entrance area
Replies: 6
Views: 5708

re: Entrance area

Rafa said: >I want a 10 to 15 cm of lenght ramjet , no more . I think that i can use >simply gasoline , with the maximum purity , adding a bit amount of >Nitromethanol ( very rapidly combustion near an explosion ) >Can i make the body of the ramjet larger than one ramjet bigger , >in compartion with...
by Glenn Olson
Mon Jun 20, 2005 7:48 pm
Forum: Ramjet forum
Topic: Entrance area
Replies: 6
Views: 5708

re: Entrance area

Rafa posted: >Thanks Al Belli , but i have these document many years ago and i >don´t remember if it says something about the minimun entrance >area.In the document that you post is impossible to see the diagram >about the entrance area and thrust. Try http://www.alt-accel.com/arla/decker/ramjet.ht...
by Glenn Olson
Fri Nov 05, 2004 8:20 pm
Forum: Ramjet forum
Topic: Ramjets and Turbojet combustors
Replies: 7
Views: 5825

Re: Ramjets and Turbojet combustors

Trapped Vortex flame holders and the combustor designs that use them are a relatively broad area of research. Such research projects abound throughout the world, by government agencies, universities, and companies. They come in many different sizes and shapes. I've seen them with both small and larg...
by Glenn Olson
Thu Nov 04, 2004 7:00 pm
Forum: Ramjet forum
Topic: Ramjets and Turbojet combustors
Replies: 7
Views: 5825

Re: Ramjets and Turbojet combustors

There are similarities between ramjet combustion chambers and those of turbojets. However, modern turbojet combustion chambers tend toward the complex with swirl vanes, high pressure spray nozzles, surface cooling boundary layers, and etc. Production ramjets are more akin to afterburners with simple...
by Glenn Olson
Thu Oct 21, 2004 7:08 pm
Forum: Valved pulsejet forum
Topic: Do i need a venturi?
Replies: 13
Views: 7302

Re: Do i need a venturi?

A few years back I talked to an old pulse-jetter who described what he called (as I recall) an afterburner for pulsejets. What he described was basically a sleeve or tube that engulfed the pulsejet turning it into a pulsejet-powered pressure jet. That is, the exhaust of the pulsejet entrained air in...
by Glenn Olson
Thu Aug 12, 2004 10:37 pm
Forum: Tools and Construction
Topic: Where can I buy a Model T coil
Replies: 15
Views: 9616

Re: Where can I buy a Model T coil

I've found two good off-the-shelf sources of sparks. My new barbecue grill came with a battery (AA) igniter that pulses at about 4 HZ and it powers four spark gaps at once. It looks real cheap but I haven't tried to buy one yet. About a year ago my bug zapper's plastic case melted (too close to the ...
by Glenn Olson
Tue Apr 20, 2004 3:22 am
Forum: Ramjet forum
Topic: Flame Holders
Replies: 3
Views: 3926

Raymond, As Stephen has stated there appears to be little work available specific to amateur ramjet flame holders. NASA (as NACA) accomplished a large number of tests of flame holders in the late 1940s and 1950s. I suggest you start with http://www.alt-accel.com/arla/arla-bp.htm where you can find m...
by Glenn Olson
Fri Mar 19, 2004 5:57 am
Forum: Ramjet forum
Topic: Scramjet projects still alive and kicking
Replies: 1
Views: 2836

NASA is currently checking out the B-52 mother ship. I noticed they've been moving it around Edwards AFB flightline lately. The pylon was attached when I saw it but not the test vehicle. I find in interesting that they are using the old B-52B rather than the newer B-52G they received about a year ag...