How to make helix with tube that has oval outer shape and inner circular shape and vice versa

need it for project for heat exchanger pipes in solidworks preferably

7 Answers

I can't understand the matter of "oval outer shape and inner circular shape and vice versa". Could you upload an image? then I upload a final model with solid parts

Exactly like the photo below. I used the cavity command to subtract the inner helix (the oval one) and thus I have hollow oval inside but I need the outer one alone.

Yoy draw a circle in the front plane (center 0,0) with the radius you need, insert a curve spiral, pitch you need, star angle 270 deg. it is important this angle for locating the sketch in the front plane (fig 1). Open a sketch in the front plane, in the point helix begin (fig 2) draw a circle and an ellipse inside.Feature - swept boos/ base, choose the last sketch as profile and the helix as the path (figure 3)

I tried it, but i ended up with either the circular or the oval. i had two options sketch 1 the circular or sketch 2 the oval.

Great!!!