Re doubt calculation and classification high-low
 

Hi,

i have to analyze a rectangular duct L= 124[mm] h=3[mm]. Liquid=water , U=10 [m/s]

- For the calculation of Re i have to use hydraulic diamter or h ?
- Re =57000 is high o low Reynolds Number ? trying different turbulences model i found a lot of difference beetwen high and low re models.....
-what turbulence model do you suggest ? For similar problem with L=1390[mm] h= 3[mm] ... can i consider it as a duct ?

I just know that you must use h for the calculation of Re. What is the viscosity value in your case?

Kinematic viscosity is 1e-6.

In that case your Re is 30,000 (high). Which is more than enough for a turbulent flow to occur inside a rectangular duct. I don't have any idea with respect to turbulence model though!