Comsol asking for Dynamic viscosity

Hello,

I am pretty new for COMSOL. I am trying to build a simple model of a heat exchanger foundation. The model is part of solid and fluid, I, therefore choose Turbulent Flow and Heat Transfer in Fluids. When assigning material properties I use the blank material function to create for soil but it asks me to fill in dynamic viscosity. I do not know the value to fill to soil. I have attached the model photo I am working on.

Thanks in advance for your help.
Theary