Streamline Tube/Strut 2

[SwiftyOE]

I have to model various extruded aluminum streamline tubes. Is the an airfoil number for these? So far all I can find is simple cross-sections with major, minor and wall thickness.

 

[berkshire]

Most of them are simply half round ovals.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[rb1957]

Bruhn has a table of streamline tube sections ... as BE says above, most likely just an ovalised section, rather than a NACA airfoil.

if you're trying to model an existing extrusion, why not grab a piece, or ask the extrusion c/- for drawings of their dies ?

 

[SwiftyOE]

The shapes are definitely not oval and are tear drop. The tubes I'm looking at are COTS for light sport aircraft form aircraft supply companies and not from the extrude/shaper. I was hopeing there was a standard shape or spec for them. However this may not be the case.

 

[rb1957]

if they're extruded, then they've come from some defined shape; ask a supplier.

 

[der8110]

The MS33534 spec should have all the proportions and relationships you need - but the COTS statement makes me wonder if the extruder may have taken liberties (not followed this spec). Also the MS is for taking round 4130 and mashing it into a streamline or oval. Not so constrained dimensionally with extrusion.

Been dealing with the same issue myself, except with GM versus Toyota roof racks - soon to purchase the third set of adapters for the kayak racks.

 

[berkshire]

A "half round oval" is a teardrop shape. it is half round on one side and an oval or ellipse shape on the other.
Illustration of streamline tubing from Wag-aero

http://store.wagaero.com/product_info.php?products_id=14719

description of half oval from WiKi

http://en.wikipedia.org/wiki/File:Oval1.svg

B.E

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[thruthefence]

Isn't the trailing edge "half" a parabola?

 

[WKTaylor]

For aerodymanic drag eval: check out Hoerner's "Fluid Dynamic Drag". There is a section on streamlined bodies including bodies similar-to streamline and oval tubing sections.

Regards, Wil Taylor

Trust - But Verify!

We believe to be true what we prefer to be true.

For those who believe, no proof is required; for those who cannot believe, no proof is possible.

 

[berkshire]

thruthefence
"Isn't the trailing edge "half" a parabola? "

It easily can be, I was trying to keep it simple.
B.E.


The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor