While deriving for a momentum equation with elastic stress effects, I am planning to put a ratio between elastic modulus (in Pa) and dynamic pressure (in Pa) in a simplified form.

I am not dealing with compressible flow or acoustics; should we still denote it as Cauchy number or modified-Cauchy number?

My equations are related to thixotropic flow where the time scale for relaxation is infinity. Hence, I am unable to use Deborah or Wi to any significance.

#Transport Phenomena

#CFD @CFD

#Navier_Stokes

#Complex Fluids

#Non-Newtonian Flow

#Rheology