How loud is a PressureJet?

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PulseDuuude
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How loud is a PressureJet?

Post by PulseDuuude » Sun Jan 02, 2005 6:12 pm

Just a quick question for anyone who has ever heard a PressureJet run.

How loud is a PressureJet in comparison to a PulseJet?
Jim

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Re: How loud is a PressureJet?

Post by Mr. Yuk » Sun Jan 02, 2005 7:13 pm

http://www.rqriley.com/gluharef.html

On that page is a video of a pressue jet running, also is just the audio of that video.


-------------------------

http://www.dangerouslaboratories.org/

On this page there is also video and audio.

Viv
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Re: How loud is a PressureJet?

Post by Viv » Mon Jan 03, 2005 4:39 am

PulseDuuude wrote:Just a quick question for anyone who has ever heard a PressureJet run.

How loud is a PressureJet in comparison to a PulseJet?
A 130R running at 145 lbs of thrust produces 150 dba at 1 metre from the exhaust.

Also if you stand at 45 deg to the exhaust from about ten feet it affects your breathing as you can feel the vibrations in your chest!

In comparison a Rolls Royce Derwent jet engine only produces 130 dba at 1 metre from the tail pipe (measured at 45 deg)

The BCVP mark 5.1 attracted the attention of a small somerset suberb when it first ran much the detriment of the two experimentors:-) think of a field artilery peace firing once a second and you get the idea:-)

A pulse jet should not be operated with out hearing protection as even a small one will produce enough sound energy to affect your hearing, most of them would breach any industrial safety regulations you care to mention.

Viv
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PulseDuuude
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Re: How loud is a PressureJet?

Post by PulseDuuude » Mon Jan 03, 2005 5:17 pm

Thank you!

Now I know what one sounds like...and have had my hopes dashed for a 'quiet' engine.....
Jim

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Re: How loud is a PressureJet?

Post by Bruno Ogorelec » Mon Jan 03, 2005 5:50 pm

PulseDuuude wrote:Now I know what one sounds like...and have had my hopes dashed for a 'quiet' engine.....
As I read on a rocketry website -- I am quoting from memory -- "Jet engines are very noisy; rockets are still noisier, but pulsejets re-define noise."

People say that the pressure jet is about as noisy as a pulsejet. Given that it is a kind of pulsejet, I am not surprised.

Still, 150 dB... powerful stuff. If we could only turn that sound energy into a propulsion force more effectively...

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Re: How loud is a PressureJet?

Post by Mike Everman » Mon Jan 03, 2005 6:22 pm

There's a guy making whistles that will compete with that! Actually, 135 db at 100 feet away! Yikes. That's a real attention getter, and it's reason for existence.
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Re: How loud is a PressureJet?

Post by luc » Tue Jan 11, 2005 2:37 pm

Hi PulseDuuude,

PulseDuuude wrote:Just a quick question for anyone who has ever heard a PressureJet run.

How loud is a PressureJet in comparison to a PulseJet?
To complete Viv's comment, a pressure jet, as I have measured is 150 dBA at one meter.

A 357 magnum hand gun is 140 dBA at the same one meter from your hears. Now, multiply this by 136 puslsation per second (136 Hz, which is average pressure jet operation cycle) and you get a big noise generator.

Hope this answers it all.

Cya,

Luc
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Mark
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Re: How loud is a PressureJet?

Post by Mark » Thu Jan 13, 2005 9:32 pm

Here's my 140 dBA.
Mark
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Re: How loud is a PressureJet?

Post by Tom » Thu Jan 13, 2005 10:01 pm

Wow, gun laws here have softend me, I actually took a double take after half choking lol. That's a nice pea shooter : oP

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Re: How loud is a PressureJet?

Post by luc » Thu Jan 13, 2005 11:10 pm

Wowwww,

Nice gun Mark.

Correct me if I am wrong ... This is a Dan Wesson .357 mag. or a Smith & Wesson Cobra .357 mag.

My father has both Dan Wesson .357 and 44 Mag. But I still have a hard time differenciating both the Cobra and the Dan Wesson.

Nice gun Mark.

Cya,

Luc
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steve
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Re: How loud is a PressureJet?

Post by steve » Fri Jan 14, 2005 1:40 am

C'mon Mark! If you were a real man you would have a chopped SW 500 ;-)

(those guys at smith & wesson are nuts! they are just asking to be sued for broken wrists etc.)
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Re: How loud is a PressureJet?

Post by Mark » Fri Jan 14, 2005 3:52 am

Mine is a 357 Smith and Wesson. The little snub nose one is probably better balanced. Mine feels kind of heavy.
I use to go target shooting and shot my brother's 44 magnum. It's funny, shooting a large puddle from a fair distance with the 44, I remember it launching a large beam of water straight up, it's interesting to think about what's going on there.
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Re: How loud is a PressureJet?

Post by Mike Everman » Fri Jan 14, 2005 4:45 am

Same reason craters are always round, no matter at what angle the meteorite came in. Can't remember why, though.
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Re: How loud is a PressureJet?

Post by larry cottrill » Fri Jan 14, 2005 1:30 pm

Mike Everman wrote:Same reason craters are always round, no matter at what angle the meteorite came in. Can't remember why, though.
I beg to differ. In my 1884 version of Steele's Astronomy, there is a carefully drawn landscape of the lunar surface clearly showing craters pointing up at interesting angles.

It also explains that the sun is probably a huge ball of coal burning in the air of space.

L Cottrill

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Re: How loud is a PressureJet?

Post by Mike Everman » Fri Jan 14, 2005 3:08 pm

I sit corrected. :-)
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