Modelling a spirally corrugated wall on a helical tube

[Fsadni]

Dear All,

I need to model a spirally corrugated wall on a helically coiled tube as per the attached image. This maybe a simple problem, but somehow I am stuck! Any help would be appreciated

 

[Valmic]

Dear Fsdani, try in this way:
1-create a curve with a polar coordinate system:
r = 80
theta =4 * t * 360
z = 200 * t
2-create a sweep with this curve (tube)
3-create another curve with a polar coordinate system:
r = 80 + 15 * cos ( 40 * t * 360)
theta =4 * t * 360
z = (200 * t) + 15 * sin (40 * t * 360)
4-create a sweep with this curve (channel around the tube)
5-Now you can merge the surfaces

 

[Valmic]

UPDATE
you can create some parameters to control this part:
D: diameter of the spiral
DT: diameter of the tube
DC: diameter of the circular section around the tube
NS: numbers of spirals
NC: number of corrugations around the tube
HS: height of the spiral
First curve:
r = (D/2)
theta = NS * t * 360
z = HS * t
second curve:
r = (D/2) + (DT/2) * cos ( NC * t * 360)
theta = NS * t * 360
z = (HS * t) + (DT/2) * sin (NC * t * 360)