topic Re: Changing profile outline on a curve in Fusion Design, Validate & Document Forum

Changing profile outline on a curve

ryanZY2YJ — Wed, 25 Oct 2017 00:07:16 GMT

I'm trying to create a ducted fan shroud that uses one airfoil profile at the bottom of the cylinder (6 o'clock) and morphs into another profile at 3 and 9 o'clock.

What would be the best way to go about doing this in fusion?

Thanks in advance for your help.

Re: Changing profile outline on a curve

davebYYPCU — Wed, 25 Oct 2017 00:15:46 GMT

Create the LE and TE rails,

create ribs on origin planes, connected to those rails, then loft.

most ducts would not change airfoils, the picture supplied uses the same airfoil, and that would, be a revolve.

different story for the blade, but you didn't mention them.

Might help...

Re: Changing profile outline on a curve

ryanZY2YJ — Wed, 25 Oct 2017 00:20:12 GMT

Thanks Dave, I'll give that a try.

I'm working on a Custer channel wing, which does create lift. https://en.wikipedia.org/wiki/Custer_Channel_Wing

I'm just playing around. We'll see how this goes.

Ryan

Re: Changing profile outline on a curve

davebYYPCU — Wed, 25 Oct 2017 00:31:30 GMT

Be aware that Loft will try to shrinkwrap the surfaces, so some spar rails will help, but more than three ribs will likely be needed.

Re: Changing profile outline on a curve

ryanZY2YJ — Wed, 25 Oct 2017 00:36:15 GMT

How would I make ribs that morph form the one airfoil profile to the other? Is there a way to do this automatically?

Re: Changing profile outline on a curve

davebYYPCU — Wed, 25 Oct 2017 02:00:11 GMT

Not automatically,

Use 5 ribs in the half wing, and the leading edge as a centreline for the Loft,

Review the file, copied developed ribs to the Leading Edge.

Re: Changing profile outline on a curve

ryanZY2YJ — Wed, 25 Oct 2017 13:35:25 GMT

Thanks Dave. This is perfect!

Re: Changing profile outline on a curve

ryanZY2YJ — Wed, 25 Oct 2017 21:59:48 GMT

How do you figure out the correct profile of each of the ribs as each rib morphs from the one airfoil profile to the other?

Re: Changing profile outline on a curve

davebYYPCU — Wed, 25 Oct 2017 23:06:28 GMT

Step through the file with the timeline, something not sure of,

Right mouse click the timeline icon, and select edit feature to see my settings

I made the wing as a flat version, (random sizes - looks about right),

Made midplane construction planes

created sketches for the 3 unknown ribs.

Used Project > Intersect > Body and clicked the flat wing,

Created the leading edge circle, then an axis from the centre of the circle.

Plane at Angles from that line for the 3 inclined ribs,

Project > Intersect > Article for the LE curve / position, (purple point).

Copy pasted the flat ribs to the inclined sketches, aligned to the leading edge point (important bit).

Loft with centre line.

Should work ok, with your data.

Re: Changing profile outline on a curve

ryanZY2YJ — Thu, 26 Oct 2017 00:18:26 GMT

The part I am stuck on is how you made the sketches for three ribs.

How did you get them to have the correct graduation between the original two airfoil profiles?

Re: Changing profile outline on a curve

davebYYPCU — Thu, 26 Oct 2017 01:17:30 GMT

Create a Midplane, between both known ribs

Create two more mid planes between the centre plane and the known ribs.

created sketches for the 3 unknown ribs on the midplanes.

For each sketch - Project > Intersect > Body and clicked the flat wing. Stop sketch.