Eliot Peterson of Clipper found that answers from WT_Perf did not change much when toggling between sheared and unsheared flow. This was caused by an ancient bug that appeared when specifying dimensional input parameters. I was dividing the nondimensional local radius by the dimensional hub height in the wind-shear calculation. This made the shear very tiny.
Please stop using previous versions of WT_Perf and start using the new alpha version:
My sincere apologies for any problems this may have caused.