Whenever we modify WT_Perf, we run a series of test cases and compare the output files to those created by the previous version. This is useful only if no significant changes are made. When the algorithms change, it is more suitable to compare the results graphically. To this end, we have created Excel charts to compare the results from the new version of WT_Perf with results from the old version and WT_Perf-equivalent YawDyn models. YawDyn uses the AeroDyn subroutine library to compute its aerodynamic loads.
When looking at the verification plots, you will notice that WT_Perf and YawDyn usually agree very well at low wind speeds. They do differ some at higher wind speeds. This difference results only when tangential induction and tip losses are both enabled. We believe this is caused by an error in the way AeroDyn treats the losses in the tangential-induction equation. We plan to replace the AeroDyn induction equation with the one from WT_Perf, which we believe is correct.
This page was generated by createpageverif.pl on 06-May-2005 at 14:53:54 MDT.
Questions about the NWTC Design Codes web pages? Contact Marshall Buhl.
The National Wind Technology Center is operated by the National Renewable Energy Laboratory (NREL), a national laboratory of the U.S. Department of Energy.