I think you need to do some thermal analysis before you settle on a fin cross-section. Tapering the fin may not result in the best heat transfer.
That’s going on in parallel, the concept of significantly improving heat transfer using a tapered fin. I am a EE, so have limitations in material science and thermal dynamics. Sent a few emails to university of Chicago professors, hoping for a call back.
Once you settle on a fin design, just find a good local machine shop, take it there, and see what they recommend. The most cost-effective production method may be something you haven’t considered (something weird, like a combination of extrusion and stamping).
For your application a different shape to the fin may be more practical than using a tapered sheet of metal. For instance serrating one part of the fin may increase transfer of heat to that part because of greater surface area to radiate, or perhaps even just folding the metal at some locations. You may do best by finding the manufacturers of radiators and asking them.
My first job out of college was as a tooling designer for Ball Metal Container, then the largest aluminum can manufacturer in the world. I spent my time designing the punches, dies, mandrels, etc… that were used in the draw and iron presses and the neckers that made and shaped the can.
I did do some work for the engineer that was in charge of making the lids, though this was only a few weeks (20 years ago), and in my memory I am >90% sure that the lids are uniform thickness with the possible exception of right at the flange where the connect it to the can body.
I spent the first 4 years of my career working in this industry and I must say I was happy to put it behind me. High production industrial environments are just not for me…
I appreciate the quick responses here, you are the second one to tell me this so I am inclined to believe it.
Wondering if anyone on this forum might have a contact who could help me quantify an improved heat transfer through a thicker to thinner aluminum fin. In this case, I am absorbing energy into the fin as opposed to radiating it. We are also open to modifying the shape of the fin.
Thanks in advance.