is there any way to do a curved screen with a normal 16:9 PJ?

No. The closer Proximity of the ends to the projector would always result in a "flaring" of the sides. Even Anamorphic lenses are not immune to that effect.

A curved screen was/is primarily intended to help reduce the effect of ambient light coming in from each side, and/or to focus projected light back to within a specific viewing area. Some High Gain screens utilized curved design so as to equalize the brightness difference between the center of the Screen and the edges.

The amount of "flaring" is of course dependent upon the degree of radius of the screen, and many times the overspill at each corner is slight enough that effective Trim masking rakes care of such.

Why do you need a curved screen?

You can use a computer program that conforms to the shape but guessing it will end up costing some money

Ok Capn'

Chart a course instead into known waters.

By most accounts, the curved Screen has gone the way of the DoDo.

Not necessary and too much of a PITA. Better Screen surfaces (...especially DIY ones... ) PJ brightness and their improvements on projected uniformity values have made such designs outdated.