What kinds of commercial CFD programs or codes are good for the analysis of screen printing application (rheology analysis? We are now eagly looking for them.

(1). I guess it depends on the Reynolds number, which is a function of the roller speed.

There is incorrect information in Mr. Chien's response. In Non-Newtonian fluid flow, which is classifed as study of Rheology, you can not have Reynolds number similar to Newtonian fluid flow. The viscosity is non-linear function of shear rate so that you can only get so called "equivalent Reynold number". Also, the number is dependent on what models you use-power law model, Carreau-Yasuda model and so on. Please refer to 'Dynamics of Polymeric Liquids' by R. Bird for further details.

Concerning commercial codes, I'd like to recommend Polyflow. I heard that it is one of best code for Non-Newtonian fluid flow. If you want to stick to the power law model, you can use Fidap(I have some experience) or other popular software. They usually include basic features of Non-Newtonian fluid flow in their codes.

Jaret

(1). Thank you, I am happy that there are experts and codes available to do screen printing. (2). How do you control the print quality? the ink, or the code?