Hi billis, to make the Rhino flow command work, you would use an arrangement like I have attached here.

Note how there are 2 separate curves - one straight line and then just one curved one.

Start by selecting the shape (which you will notice I extruded into a solid). Then run Flow, select the line as the base curve, and then the other curve as the target curve. That will then warp your pattern to follow the curve.

You may also want to experiment with flipping the Stretch=n option on or off.

I hope that might help you - but please realize that this forum is not the right spot for answering questions on how Rhino works. There is a totally different forum dedicated to Rhino located here - that is normally the place you should go to ask questions specific to Rhino.

- Michael