Mesh Swept Problem

Dear All,

I need to reduce the elements of the mesh in the fluid domain.
At the beginning I used a tetrahedral mesh but it is too dense in the axial direction, while I need it mainly in radial direction.

For this reason I'm trying to create a triangular mesh on the boundary of the domain 2 and sweep it in the axial direction. (Attached 1.png)
The source and the destination faces are not the same, how can I build a lighter mesh in this domain (2.png) ?

Thank you in advance for your support!