Help on drag coefficients

B12se-R

I'm kind of stuck in my search, hoped to be able to find some answers on this board.

Anyways, I've been taksed to design a slow speed mixer and I'm trying to look up information beyond Stokes Law of F_D = 6 pi r V u

The fluid to be mixed is approx. 100000 poise, incompressible fluid. I'm trying to find how to approximate a proper drag coefficient and calculate a drag force on a rotating mixer blade. Cross sectional footprint of one tine passing through the fluid is approx. 3" x 1/3". Low speed, so Re << 1. density is 1.3 g/cm³

Can someone throw me a bone plz?