radial turbine flow analysis

ME

Hi, everybody, I am simulating radial inflow gas turbine. For that i m finding these queries. pls let me know if anybody knows (1) Which type of BCS should be used? Inlet total pressure is 2.73 bar and total temp is 923 K. which type of inlet turbulence shu be specified? (2) which type of turbulence model should be used? Should I use spalart allmaras, ke (low RE) or Reynolds stress model? I was thinking to apply ke initially and once it is getting converged, then switch over to RSM. Pls also let me know, that is there any low Re model in fluent?(3) how much should I extend my domain at inlet and outlet? Is that any thumb rule? (4) Presently i am thinking to run analysis at 10 percent of speed and then slowly increasing it once it is converged? (blade speed is 60,000 rpm). Is it ok? is tht ant thumb rule? (5) If I want to take secondary flow into account, then what shud me my mesh requirement? (6) Shud I do transient or steady? Thanks a lot.