AIRCRAFT BULBOUS BOW
AIRCRAFT BULBOUS BOW
(OP)
Would a bulbous bow on the front of an airplane, similar to a bulbous bow on a ship, reduce drag on the airplane.
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: AIRCRAFT BULBOUS BOW
Certainly if going fast enough that compressibility is a concern the simple answer is no.
However, depending on exactly what you mean then aerospikes are occasionally used in very high velocity applications.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: AIRCRAFT BULBOUS BOW
there have been some examples of what you're thinking, compare a standard DHC8 with a CT142 (a radar trainer for the Canadian Forces).
another day in paradise, or is paradise one day closer ?
RE: AIRCRAFT BULBOUS BOW
I don't understand your comment "bulbous bow is it improves the water/air boundary" In a ship the bulbous bow is completely below the water line therefore is doesn't seem like the air/water boundary would come into play?
RE: AIRCRAFT BULBOUS BOW
another day in paradise, or is paradise one day closer ?
RE: AIRCRAFT BULBOUS BOW
The bulbous bow solves issues related to moving in an incompressible fluid, while air is not.
TTFN

FAQ731-376: Eng-Tips.com Forum Policies
Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers
Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
RE: AIRCRAFT BULBOUS BOW
http://www.flyaria.com/index.html
Look under the link that says "The Aircraft".
RE: AIRCRAFT BULBOUS BOW
If you want to discuss wave drag in compressible fluids (air for example), that's a different subject. Read up on the area rule (see F104), aerospikes like Kenat mentioned, and Bussman biplanes.
RE: AIRCRAFT BULBOUS BOW
TTFN

FAQ731-376: Eng-Tips.com Forum Policies
Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers
Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
RE: AIRCRAFT BULBOUS BOW
If you ever want to discuss wave making drag of ships, let me know!
Incidentally one interpretation of the bulbous bow is that it is an impedance matching device between the sea surface and the ship.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: AIRCRAFT BULBOUS BOW
RE: AIRCRAFT BULBOUS BOW
Nice analogy, I think. Like tuning an exhaust muffler, or a mass-spring damper, one would tune the bulb for a given hull speed?
"If you ever want to discuss wave making drag of ships, let me know!"
Go for it, Greg. I'm no expert, but willing to be educated.
RE: AIRCRAFT BULBOUS BOW
an article for the writer's guild ?
another day in paradise, or is paradise one day closer ?
RE: AIRCRAFT BULBOUS BOW
I have a vague recollection of the odd exception where the larger dia nose cone did improve drag but I can't remember details.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: AIRCRAFT BULBOUS BOW
The fundamental work on this was done in the 1800s when people had too much time on their hands. Havelock approximated the hull of a moving ship by a source at the bow and a sink at the stern, each with a strength v*A. From this he worked out the interference pattern of the surface waves, which results in a v shape from the bow and a trailing pattern of curved transverse waves following the stern. When the ships length is the same as the wavelength of the surface wave the pattern is at its strongest, as its drag.
All subsequent analysis builds on that simple model, it is a brilliant piece of work. That model is good enough for typical catamaran type hulls, with semicircular cross sections of constant cross section.
http://www.cyberiad.net/library/pdf/tsl00.pdf is a nice intro, Leo L is a very cluey and helpful guy.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: AIRCRAFT BULBOUS BOW
computing equipment, to evaluate with 2-figure accuracy, the triple integral for the resulting inviscid drag force or wave resistance."
another day in paradise, or is paradise one day closer ?