Steam Car Club Forum
Steam Car Club : The Steam Car.....Forum
The Official Forum for the Steam Car Club
The fastest message board....ever.
Having trouble logging in or posting messages? Email forum@steamcar.net for help.
Goto Thread: PreviousNext
Goto: Forum ListMessage ListNew TopicSearchLog In
Goto Page:  Previous12
Current Page:2 of 2
Re: Howling Burners
Posted by: Rolly (---.hsd1.ma.comcast.net)
Date: April 8, 2010 08:09AM

Iíll let you know how it works Mike when I get this burner running
Iíve never tried this before.
I remembered I had a photo, see attached.
Rolly

Attachments: P4070001a.JPG (87kB)  
Re: Howling Burners
Posted by: (---.armstrong.com)
Date: April 9, 2010 07:43AM

Here's another data point for the mixing tube theory. The 3-nozzle burner in Tom Marshall's Stanley Model K has a center mixing tube that is 19" long, and 2 outer mixing tubes that are 16" long. I've heard this car when the burner howls with all 3 jets being fed, and it sings a duet - 2 distinct pitches.

Re: Howling Burners
Posted by: Mike Clark (---.bb.sky.com)
Date: April 9, 2010 05:21PM

That's interesting Kelly.

Clearly we would expect different lengths of venturi to play a different note but how does that square with the idea that the flame oscillation frequency is synchronised by the venturi resonance? If the venturis are resonating at different frequencies how can the flame follow, unless there is more than one mixing chamber due to partitions below the burner plate. Are there? Our idea of having two lengths of venturi was that this would confuse the flame and stop the howl - as I said - it didn't!

Mike

Edited to add - of course if by chance the lengths of the venturi tubes were such as to produce resonances spaced apart by an octave then the two notes might match with a common flame oscillation frequency.



Edited 1 times. Last edit at 04/10/10 04:20PM by Mike Clark.

Re: Howling Burners
Posted by: (81.168.70.---)
Date: June 24, 2010 07:00AM

Having seen Mike's video, and John's reference to "first, find your resonant cavity", I'm drawn to the conclusion that we're looking at a Helmholz resonant cavity. Examples are when you blow across the neck of a glass bottle and an ocarina.

I think the "cavity" this case is the mixing chamber along with the venturi tubes. The natural frequency will change with local sound velocity. Mike's video seems to be demonstrating this variation between when the temperature of the mix is held down because the fuel aerosol is still evaporating, and when it rises because the fuel has already acquired all the latent heat of vapourisation it needs before exiting through the jet.

Interesting point about the overblowing. Can you "overblow" an ocarina? Sorry, I don't know.

Greg

Goto Page:  Previous12
Current Page:2 of 2


Sorry, only registered users may post in this forum.
The Steam Car Club Forum
Having trouble logging in or posting messages? Email forum@steamcar.net for help.
Web by NPC