How to project a spline onto a cylinder???

I think I understand....

I think my question was not clear, I'll try to make it clear. I have aerofoil on a plane which is as shown in fig.3 of attachments they are lying on the different parallel planes. but I want to have them like how they are shown in images 1 and 2. In images 1 and 2, the aerofoils are projected onto right circular plane fashion. I have attached the igs file of various splines.

Much better.

CFD typically drives this type of design, whereas the final shape is simply a function of the multitude of airflow requirements. In this, you're working backwards, so I'm going to assume this is a bit of an academic modelling exercise?

You will need to create the surface sections you'd like to project to, which will likely look spherical... and may very well be spherical, though the centers looks to be further displaced in each section. I haven't queried your igs file yet so take what you will from that.

The projection may be driven along a vector and I wouldn't worry too much about it as an academic exercise. If it were a CFD driven design, then this was the wrong approach from the word 'go'.

cmlaco explanation is excellent.

You have an application example, in this great work by Domen Starman
Wind turbine

Domen Starman, he found the formula on the web.

https://en.wikipedia.org/wiki/NACA_airfoil
http://airfoiltools.com/airfoil/naca4digit

It depends on the software which are you using its most easy in case of solidworks which have a Wrap Feature in 3D tools which make things easy for projecting spline onto a cylinder. In Case of other software search their specific Website

Wrap command.

Here's the link for tutorial dude...
https://www.youtube.com/user/nanthukk007