Search found 39 matches

by Bruce Simpson
Sun Apr 11, 2010 10:45 pm
Forum: Valved pulsejet forum
Topic: 85% throttable pulse jet engine.
Replies: 26
Views: 11937

Re: 85% throttable pulse jet engine.

Pulsejets are more like diesel engines than gasoline ones. Within limits (imposed by various factors such as total intake area, valving losses, pumping capacity, etc), they automatically respond to changes in fuel flow by drawing more (or less) air so as to maintain the stoichiometric ratio required...
by Bruce Simpson
Sat Apr 03, 2010 9:54 am
Forum: Off topic forum
Topic: Problems getting PulseJet CDROM from Aardvark
Replies: 2
Views: 2145

Re: Problems getting PulseJet CDROM from Aardvark

If anyone has had difficulties then please email me using the address dontspam at yahoo dot com and I'll sort it out. Please include the world "Aardvark" in the subject so that your email isn't swallowed by the spam filter.
by Bruce Simpson
Sun Mar 28, 2010 2:26 am
Forum: Valveless pulsejet forum
Topic: Help for pulsejet
Replies: 9
Views: 3151

Re: Help for pulsejet

I'm starting to remember why I was way so long :roll:
by Bruce Simpson
Tue Mar 23, 2010 8:19 pm
Forum: Valved pulsejet forum
Topic: Another pulsejet kick from Sweden
Replies: 73
Views: 23914

Re: Another pulsejet kick from Sweden

Yep that pretty well describes it. Also the point that it dips at, would be the same point in free space, that would create a virtual venturi, with the 'nozzle' being made up of a toroidal region of static / recirculating flow, and happens to be where an augmenter should be positioned. I just poste...
by Bruce Simpson
Mon Mar 15, 2010 8:52 pm
Forum: Valveless pulsejet forum
Topic: origonal ???
Replies: 33
Views: 8640

Re: origonal ???

Yes, given the correct degree of confinement, the tailpipe flow can approach the speed of sound at the temperatures involved (which would be supersonic at normal (external) ambient temperatures) However, I've never seen (nor heard of) the flow being sufficiently fast or sustained to create a shock d...
by Bruce Simpson
Thu Mar 11, 2010 3:40 am
Forum: Valveless pulsejet forum
Topic: Bleeding Pressure
Replies: 6
Views: 2182

Re: Bleeding Pressure

Note that you don't actually need a non-return valve in the pressure line -- in fact things work much better without one. The advantage of not using such a valve is that if/when the engine stops, the tank pressure can rapidly bleed out the pressure hole rather than continuing to force fuel into the ...
by Bruce Simpson
Wed Mar 10, 2010 10:04 pm
Forum: Valveless pulsejet forum
Topic: Liquid fueling
Replies: 16
Views: 5424

Re: Liquid fueling

I'm running 10lbs-thrust valved engines on my model aircraft now and they are *more* than powerful enough for the average ARF model. As an example, the TameCat ARF weighs in at 6.5lbs (plus another 0.5lbs for fuel) and with a 10lbs-thrust engine it is very fast, despite its huge wing area and very d...
by Bruce Simpson
Wed Mar 10, 2010 8:02 am
Forum: Valveless pulsejet forum
Topic: Liquid fueling
Replies: 16
Views: 5424

Re: Liquid fueling

I want to get into liquid fueling. I've been tugging around propane tanks for to long now, time for a change. I eventually want to get into valveless planes, starting off with a plane that will carry my 40 pound chinese. Looking for a big plane that does not have a high top speed to get into things...
by Bruce Simpson
Wed Mar 10, 2010 7:47 am
Forum: Valveless pulsejet forum
Topic: Bleeding Pressure
Replies: 6
Views: 2182

Re: Bleeding Pressure

You can bleed combustion pressure to generate fuel pressure, my valved engines do this. By choosing the right size of pressure hole and jet-size, the engines will run reliably over a wide range of fuel-head (+/- 300mm with ease), something an aspirated valved-engine won't normally do. Be aware howev...