Reliability of CFD

[MaxKang]

Hello, me and other engineering students at my university are designing an electric aircraft and we are hoping to implement the technology that NASA is currently working on, http://www.nasa.gov/press-release/nasa-electric-research-plane-gets-x-number-new-name
Basically how it works is you have 14 electric motors placed across the wing, which gives you twice as much lift at lower speeds by accelerating the flow more.

My question is whether or not the result of theirs will be reliable for our prototype. If we choose to pick a different airfoil, I believe there could be a big difference in performance. My friend suggested using the CFD to test different motor+airfoil configurations across the wing, but I do not think we can trust CFD results. From my understanding, CFD data is only useful if it happens to match the experimental result because, if the CFD model happened to work and it should presumably predict the performance well even when the geometry(i.e. chord length) is modified. Is there a way to predict the performance of a wing in a more reliable way, without having to do a wind tunnel testing?

Thanks!

 

[aerohead_18]

Why not work in CFD until you find a solution that works in the simulation and then try testing real life prototypes from there?

 

[MaxKang]

Why not work in CFD until you find a solution that works in the simulation and then try testing real life prototypes from there?

Because there seems to be a lot of room for error in doing CFD, in fact since we need to simulate the rotational flow due to props the result might be highly unreliable. Quite a few of the Master students at my university seemed to ignore CFD and go straight to a wind tunnel testing. Once time I heard that most times CFD is only reliable for future iterations of a given design where the CFD and experimental data have already converged to the same value