I want to simulate Blood flow (Non-Newtonian) in Fluent. It is not available in Fluent material database. I want to know how to define Blood as a working material with its properties like density and power law model (for viscosity) etc.
You should to copy a very similar material and modify your properties. Then, you must to save. The properties can be added using models by using UDFs if you prefer. At the Fluent tutorial you can see some examples.