Dear @Jason.Jonkman,
I am new to WEIS. Before i start using the software, a question comes to my mind which i did not succeed to find an answer and i want to hear your opinion please.
During my Ph.D. thesis, i have succeeded to couple OpenFAST and MATLAB and was able to run an optimization procedure for TMD optimization. I found that the optimized TMD parameters in time-domain depend on the realization. For instance, if i run two different realization of a typical DLC, i will obtain different optimal TMD parameters. So, i suggest to use a free decay test to set the TMD parameters since it is a deterministic test.
I was wondering how WEIS does the design of floating offshore wind turbine ? Is it based on deterministic tests ? If yes, what are those tests? If no, then how the stochasticity of the DLCs is considered ?
Thank you in advance,
Best Regards,
Riad
Hi Riad,
It’s up to the user to determine what cases are used in the design analysis/optimization. We typically use stochastic cases (DLC 6.1 is important for TMDs), but try to include enough seeds (at least 6) to “smooth” the randomness.
WEIS has recently added free decay (and other deterministic) simulations to the modeling options. An example is here: AG_WEIS/weis/dlc_driver/test/weis_inputs/modeling_options_all_dlcs.yaml at 2084db9b4ee2d4960e74a358519d88b8a009a907 · abhineet-gupta/AG_WEIS · GitHub. Please note that this branch has not yet been merged into the develop branch.
I hope this helps.
Best, Dan
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Dear @Daniel.Zalkind,
Thank you for your response and the information you have provided.
If i understand your answer, i can use both stochastic and deterministic DLCs in WEIS but there is no “standard deterministic DLCs” that should be used when designing wind turbines. It is user-dependent.
Please could you explain more about “smoothing the randomness”. Does this mean i run lets say 6 seeds and then i take the average of the the 6 optimal designs ? If so, we are considering that the average of the different designs is the “absolute optimal” right ?
Thank you for your response.
Best Regards,
Riad
Hi Riad,
It depends on what you’ve selected as your cost functions or constraints; they can be either means, maxima, or sometimes the standards specify ways of grouping maxima and averaging them. Either way, with enough random seeds, the results should converge to a single value.
Best, Dan
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