Wake behind a two crossing cylinders
 

I want to look at the wake effect behind two crossing cylinders. The Re no. is 3800. Due to the nature of the flow over circular cylinders, I have to run the analysis transient and the mesh has to be resolved way down to the viscous sublayer. The wake has to be about 300xD, so it will be a very large model and don't have time to let it run for several days. So I thought if it would be possible to do a smaller model with a wake of about 30xD and run it transient and get a mean flow profile from the outlet boundary. Then this could be set to be inlet profile in a steady state analysis with only the long wake (300xD) and without the crossing cylinders. Has any of you done something simillar to this? How can one get the mean outlet flow profile from an transient analysis in FLUENT?