Search found 335 matches

by Anders Troberg
Thu Aug 09, 2007 6:13 am
Forum: Pulse detonation engine forum
Topic: Detonation or Deflagration?
Replies: 6
Views: 7286

OK, I'm just guessing here and may be wrong, but two things that springs to my mind are: 1. A detonation pressure wave moves faster than the speed of sound. Could it be that a fair amount of the sound energy generated is on frequencies above what the human ear can ear? There may be times when you ju...
by Anders Troberg
Thu Aug 09, 2007 6:08 am
Forum: Off topic forum
Topic: Volume of Cone Frustrum
Replies: 16
Views: 8903

a few weeks back, I did a bunch of derivation to prove that not only can you write a 3d rendering engine without using a single call to trig functions, but that it will be faster to do it that way Yep, you shouldn't need anything more complicated than an occasional division if you stick to using tr...
by Anders Troberg
Wed Aug 08, 2007 5:51 pm
Forum: Jet Vehicles, All Types
Topic: F86-HPX-Sabre, By Rossco & IrvineJ
Replies: 62
Views: 711213

Good point, Larry. It's not just a matter of remaining fuel, a red hot engine crashing into dry grass is a recipe for disaster. Edit: Keeping the fuel in drop tanks, even if not droppable, will probably increase safety a lot. Even if the aircraft is torn to pieces, they have a decent chance of remai...
by Anders Troberg
Wed Aug 08, 2007 11:54 am
Forum: Jet Vehicles, All Types
Topic: F86-HPX-Sabre, By Rossco & IrvineJ
Replies: 62
Views: 711213

Have you considered adding an "afterburner" by injecting fuel into the exhaust? Not for thrust, just for show, and potentially for burning off fuel if you wan't to lose some excess weight before an early landing.

I think it would make quite an impression!
by Anders Troberg
Tue Aug 07, 2007 11:43 am
Forum: Jet Vehicles, All Types
Topic: F86-HPX-Sabre, By Rossco & IrvineJ
Replies: 62
Views: 711213

I've seen the video now. It looks downright scary to fly, but I love it. Make sure you get a video of the real one as well before it becomes a 100 mph lawn dart!
by Anders Troberg
Tue Aug 07, 2007 11:40 am
Forum: How to improve this site
Topic: Time to bury the hatchet?
Replies: 9
Views: 7650

I don't want to go into details about who I'm talking about, as I feel it may put undue pressure on them. Let's just say that there is a bunch of people I miss and which I think the community would be stronger if they returned. I think most of them know who they are anyway. Frankly, if it has progre...
by Anders Troberg
Fri Aug 03, 2007 7:11 pm
Forum: How to improve this site
Topic: Time to bury the hatchet?
Replies: 9
Views: 7650

Hmm -- at the risk of starting an argument, I'd suggest that this is a relatively peaceful forum. Usually, yes. At times, though, people have left because arguments got out of hand, some of them among the "big names". One or more individuals who have left the forum have progressed far beyond anythi...
by Anders Troberg
Fri Aug 03, 2007 12:53 pm
Forum: How to improve this site
Topic: Time to bury the hatchet?
Replies: 9
Views: 7650

Time to bury the hatchet?

This is a wonderful site, driven by people with a deep interest in jet engines and science. However, as people are very interested in the subject, sometimes heated discussions occur. It's a byproduct of the saying "If you want one answer, never ask two specialists", and a natural part of a discussio...
by Anders Troberg
Thu Aug 02, 2007 6:44 am
Forum: Valved pulsejet forum
Topic: valve or not a valve - that's the question
Replies: 7
Views: 5334

Basically, there's three guys keeping a wing flying: Newton, Bernoulli and Coanda. The two latter kind of rides on the back of Newton. Newton works by having the angle of attack of the bottom of the wing shuffling air downwards. Something goes down, something else must go up, and that else is the wi...
by Anders Troberg
Wed Aug 01, 2007 11:49 am
Forum: Jet Vehicles, All Types
Topic: F86-HPX-Sabre, By Rossco & IrvineJ
Replies: 62
Views: 711213

Man, that saab bears striking resemblance to my ex-girlfriend... Well, "Tunnan" means "Barrel" (as in "barrel of water", not as in "gun barrel")... It was one of the earliest jets with swept wings, and once the landing gear is in and you see it in the air, it's like watching dolphins play, as it's ...
by Anders Troberg
Wed Aug 01, 2007 8:35 am
Forum: Jet Vehicles, All Types
Topic: F86-HPX-Sabre, By Rossco & IrvineJ
Replies: 62
Views: 711213

Looks hot! If it turns out well, I'd suggest having a look at the Mig-15, Mig-17, Mig-21 (that spike in the intake would be nice for aerodynamics of the engine) and SAAB J-29 Tunnan, they all practically scream for such a treatment. http://en.wikipedia.org/wiki/Mig-15 http://en.wikipedia.org/wiki/Mi...
by Anders Troberg
Mon Jun 04, 2007 10:43 am
Forum: Off topic forum
Topic: Electric Starfighter Flight
Replies: 6
Views: 3267

Not only have electric motors become much lighter and stronger, so has batteries. The rest of the electronics (reciever, servos and so on) has also become lighter and cheaper. New building materials has also made construction simpler and cheaper. The lower weight has also made slower aircraft possib...
by Anders Troberg
Mon May 21, 2007 11:19 am
Forum: Valveless pulsejet forum
Topic: Ceramic Lady
Replies: 78
Views: 46340

Perhaps some metal inside it would help it to preserve heat and thus help it self sustain, especially before it's hot? It probably don't have to be advanced, just a sliver of metal to act as a crude glow plug.
by Anders Troberg
Mon Apr 09, 2007 9:54 am
Forum: Off topic forum
Topic: Closing the window on Windows(tm)
Replies: 2
Views: 1983

I can vouch for the Ubuntu family (I run Kubuntu and Xubuntu and have tried Ubuntu), it's really a serious contender as a Windows replacement. I'm gradually phasing out Windows in favour of Linux, and currently run six Linux machines and fifteen or so Windows machines. I suspect it will take a coupl...
by Anders Troberg
Fri Mar 30, 2007 11:34 am
Forum: Valveless pulsejet forum
Topic: What happened to the Kazoo?
Replies: 7
Views: 3520

Another way of doing the intake without it going so flat that would probably be easier (although perhaps a bit more difficult to get the area right) is to make it with two stacks by squeezing the pipe in the middle, so that it forms a figure 8 or an O-O. If one is not so particular about symmetry, s...