Modeling a rotating vertical axis stream turbine
 

Hi guys, new to the forum and after digging around to find answers to my problems i am yet to find a definite answer, so i make a thread :)

I'm doing my 3rd year dissertation on modeling a Vertical Axis Tidal Turbine (VATT) in FLUENT. What i am looking at is the efficiency drop/rise when more blades are added to the arrangement (Darrieus style VATT) for example 3 airfoils compared to 4,5,6 etc.

Now i have my solidworks model of a simplified VATT imported into ANSYS Workbench, then placed inside a cylinder and the the cylinder inside a larger control volume. The model is meshed appropriately and set up using a sliding mesh arrangement with the cylinder 'fluid' volume rotating at a set angular velocity hence turning the turbine.

My many questions lie in the running solutions, obviously to model the turbine rotating over time i have to use a transient method. questions:

1) Do i first have to run a steady state solution to convergence and then proceed to a transient model (with say 50 iterations per time step?)

2) Do i record lift, drag, and moment coefficients of the turbine as a whole? and in what axes?

Thank you for your time, if you need anymore information or pictures i can provide them. Thanks again

Richard