Search found 47 matches

by alex
Tue Apr 24, 2007 4:52 pm
Forum: Valveless pulsejet forum
Topic: Augmented pulse jet
Replies: 1
Views: 1299

Augmented pulse jet

Hello all!

Is there any information about augmented pulse jets which have been used on aircrafts? I do know that the drag overtakes the extra thrust at speed. Would it be sufficient on an Ultra light glider?
by alex
Sun Apr 22, 2007 12:02 pm
Forum: Valveless pulsejet forum
Topic: Heat development?
Replies: 10
Views: 3961

Thanks. Is that the temperature of the exhaust or inside the engine? What's the distance behind the tailpipe where you can put your hand without any injury?

I'm trying to make a picture of how much the tempreature of the exhaust decrease after leaving the tailpipe.
by alex
Sun Apr 15, 2007 10:35 am
Forum: Valved pulsejet forum
Topic: Calculate ram pressure?
Replies: 1
Views: 2181

Calculate ram pressure?

Hi!

Is there a formula for calculating ram pressure at different speeds?

Thanks
Alex
by alex
Thu Apr 12, 2007 4:40 pm
Forum: Valveless pulsejet forum
Topic: Heat development?
Replies: 10
Views: 3961

Heat development?

Hi all!

I have a quick and simple question: How hot does a pulse jet become while running, static vs in air?

I understand these questions have been up before. Hope you want to help me still.

Thanks
Alex
by alex
Sun Mar 11, 2007 12:27 pm
Forum: Valveless pulsejet forum
Topic: The relationship between thrust and fuel consumption?
Replies: 12
Views: 4297

Thanks Larry!

So, the volume of the tailpipe is one factor of the peak amplitude. What decides the ratio of the CC diameter and the tailpipe's diameter?
by alex
Thu Mar 08, 2007 6:10 am
Forum: Valveless pulsejet forum
Topic: The relationship between thrust and fuel consumption?
Replies: 12
Views: 4297

Viv, or any one, You wrote: Heres some thing to add to your thoughts, having a cold plug of air in the tailpipe is good for engine performance, that dense mass gives the combustion event in the combustion chamber something to work against, this ultimately raises the pressure in the CC during combust...
by alex
Mon Mar 05, 2007 6:20 am
Forum: Valveless pulsejet forum
Topic: The relationship between thrust and fuel consumption?
Replies: 12
Views: 4297

The thrust increases in flight due to the bigger diffrential pressure. The thrust available in flight depends on the velocity of the air plane and the velocity of the hot gases leaving the tailpipe. Does the thrust increasement exceed the decreasing available thrust? I hope you understand what I mea...
by alex
Thu Feb 22, 2007 6:51 am
Forum: Valveless pulsejet forum
Topic: The relationship between thrust and fuel consumption?
Replies: 12
Views: 4297

Thanks Viv! "Frequency is a big factor as you correctly say but peak cycle amplitude is the larger factor and that depends on the pressure presented to the inlet and tailpipe and the differential between them, this is why flight speed needs to be included in your question." Should the differential p...
by alex
Wed Feb 21, 2007 5:38 pm
Forum: Valveless pulsejet forum
Topic: The relationship between thrust and fuel consumption?
Replies: 12
Views: 4297

I'll simplify my question: The frequency, and thus the thrust, can be controlled by reducing and giving more fuel right? From what I've understood from the text I spoke about earlier a lower frequency increases the air charge per cycle, because its speed into the engine is lower and therefore the st...
by alex
Sat Feb 17, 2007 12:29 pm
Forum: Valveless pulsejet forum
Topic: The relationship between thrust and fuel consumption?
Replies: 12
Views: 4297

Oh, it's the one at the pulse jet page at pulse-jets.com. It's s PDF file.
by alex
Fri Feb 16, 2007 8:07 pm
Forum: Valveless pulsejet forum
Topic: The relationship between thrust and fuel consumption?
Replies: 12
Views: 4297

Maybe I was a bit unclear. What I'm asking about is the text at page 16 in the Jet propulsion paper.
by alex
Thu Feb 15, 2007 9:35 pm
Forum: Valveless pulsejet forum
Topic: The relationship between thrust and fuel consumption?
Replies: 12
Views: 4297

The relationship between thrust and fuel consumption?

Hi all,

Can any one clarify the relationship between thrust and fuel consumption at different frequencies? I've read the paper "Jet Propulsion" but I didn't fully understand it.

Thanks in advance!
/Alex
by alex
Sat Feb 10, 2007 3:22 pm
Forum: Valveless pulsejet forum
Topic: Augmentor thrust increasements
Replies: 19
Views: 8118

Thanks guys, and a special thanks to Larry! I don't want to criticize your theory, but. As I've understood it the outmoving air has to change direction, and this "decision" is made my the air moving backwards which directs it into its own direction. But, doesn't this mean that the air moving out tow...
by alex
Thu Feb 08, 2007 8:49 am
Forum: Valveless pulsejet forum
Topic: Augmentor thrust increasements
Replies: 19
Views: 8118

Augmentor thrust increasements

Hello all,

I'm writing an essay about pulse jets and now I came to augmentors. Is there any general rate of thrust increase these make? Like 20% of the original engine thrust. I hope you understand what I mean.

Thank you!
/Alex
by alex
Wed Jul 05, 2006 12:47 pm
Forum: Valveless pulsejet forum
Topic: Jam jar failure
Replies: 14
Views: 4533

re: Jam jar failure

All my jam jar jets have cracked into two parts, no smaller pieces at all.