NWTC

Hello Simon, Unfortunately, we do not have the resources to supported pre-compiled versions of MLife at this time. The good news is that you can still use MLife! You simply need to create your own version of the Weibull cumulative distribution function, wblcdf() function. https://www.mathworks.com/h...

The tilde operator was introduced with MATLAB Version 7.9 (R2009b). https://www.mathworks.com/help/matlab/matlab_prog/ignore-function-outputs.html You will need to place dummy variables where ever you see ~ in a function output list for this code to work with your version of matlab. There may be add...

For item (1), you need to modify Test02.mlif to use the StrNames functionality. It should now run without any errors. true StrNames Use channel names following a "$" instead of numbers when specifying channels in this input file. 2) You can access the binned rainflow counts via the data st...

Dear Tohid, Unfortunately I cannot reproduce your errors. I've 1) downloaded the MLife archive with the precompiled binaries ( https://nwtc.nrel.gov/system/files/MLife_v1.00.00f-gjh_1.exe ), 2) extracted the archive to a local folder. 3) Copied the contents of the Data folder into the CertTest folde...

Simon,

I have not run MCrunch with a version of MatLab newer than 2014a. Can you paste the error message you are receiving with your version of MatLab?

Thanks,

Greg

Romain, Thank you for reporting this issue. I have verified the problem in the current version of HydroDyn (v2.05). This bug was created when we added user supplied wave kinematics and with our wave stretching implementation. Some additional code is needed in the WriteSummaryFile() subroutine of Mor...

Dear Srinivasa,

wblcdf() is a MatLab function found in the statistics toolbox. You will need to have a license for this toolbox, or replace the wblcdf() call with your own code to calculate the weibull distribution.

Greg

Hello Scott, Thank you for pointing out the discrepancy between the User's Guide and the archive. At some point, I changed the name of the script to: mlife_regression_test.m This script is identical to the original mlife_certification_tests.m script. I'll be sure to update the documentation for any ...

Dear Mehdi, You might want to look at the certification tests under the CertTest folder of the MLife distribution. Test02.mlif and Test05.mlif both generate short-term DELs. If you examine the MLife_User.pdf, located in the documentation folder, you will be able to interpret the various parameters. ...

Dear Shining.Zhang, In terms of your first item, the HydroDyn manual, https://wind.nrel.gov/designcodes/simulators/hydrodyn/HydroDyn_Manual.pdf , Appendix C has a complete list of available HydroDyn outputs. There are channels for all the various load contributions due to potential flow theory as we...

Yulin, Your questions about the specification of both L_MF and L_Ult is a common one. Unfortunately, there is no general answer that I can give you. In my opinion, the answer depends on the nature of your analysis/study, and the available information you have about your turbine design. For generaliz...

Florian, as stated in the MLife User's Guide on page on page 6, "If you wish, DELs can be outputted as peak-to-peak ranges (DEL_AsRange = true) or as one-sided amplitudes (DEL_AsRange = false)." The rainflow counts themselves are tracked based on the number of full cycles (valley-to-peak-t...

We are happy to announce an updated alpha-version release of MLife (v1.00.00f-gjh), a MatLab-based tool that can efficiently process statistical and fatigue-related output needed for wind turbine certification. MLife's calculations follow the method required by the IEC in their 61400-1 Edition 3, An...

We have discovered a bug in the v1.00.00b-gjh release related to the calculation of wind speed bin probabilities. Currently the scale factor for the Weibull distribution is set to 2*Vave / sqrt(pi), but this should only be the case when a shape factor of 2 is used (in other words a Rayleigh distribu...

Call for Alpha Testers (NWTC/NREL Fatigue-life estimation Tool) We are happy to announce an alpha-version release of MLife, a MatLab-based tool that can efficiently process statistical and fatigue-related output needed for wind turbine certification. MLife's calculations follow the method required b...