CFD Model of a Small Open Jet Wind Tunnel
 

Hi I am currently doing my undergrad thesis consisting of modelling a circular wind tunnel (diameter 0.91m and length 2m) using Fluent to inspect its performance.

The first step is to validate the model with experimental data of the velocity profile at a test plane. See attached diagram for description of proposed geometry and boundary conditions.

The methodology that I'm following is:
1. Analyse the effect of geometry changes of the inlet and outlet plenum chamber on the velocity profile at the test plane
2. Refine mesh (quad mapped mesh used) by altering edge sizing and bias factor, until mesh independence is acheived.
3. Compare turbulence models

Questions:
1. What makes a good mesh analysis and what are the parameter required to determine that mesh independence is achieved ( I am looking at 2 things: volume flow rate at outlet and vel profile at test section)

2. From experimental data it is known that we have a T.I of 5% at the test section. My question now is:
What turbulence models should I try and use in order to have results close enough to the experimental data?

3. As regards to fan boundary condition I have found a simplified method of determinig the pressure jump for the system at hand from a paper by Moonen et al: Numerical modeling of the flow conditions in a low-speed closed-circuit wind tunnel
Has anybody made use of such a method?


P.S Any help is greatly appreciated as CFD study is new in my university and there is limited help available.

Thanks