Reference Values Help
 

Hello all,

I need to find Cd and Cl of flow around cylinders in water. I am using ske turbulence model.

I will use water properties as the reference values and I do it step by step.

I use Area as 0.0504m(diam of the cylinder) and velocity as 0.38m/s and leave the rest as default values. With these reference values, I get a good Cd but a wrong force as the default density is 1.125kg/m^3 whereas density of sewater is 1025 kg/m^3.

Drag force = Area x Cd x velocity ^2 x 0.5 x rho.

Next I use density as 1025kg/m^3 and area and velocity as specified above. With this ref values, Cd value drops ridiculously. To my understanding, I need to set the density as 1025 as it simulates the ocean environment, but it seems with rho of 1.125 the Cd gives good results.

Can someone out there advice me why if I change the rho to 1025 the results obtained is different but when I set rho as default, Cd gives good output?

Thanks in advance.

Sham.