Tight-Coupling Algorithm for OpenFAST 5.0 #2439
Draft
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Most changes to support variable indexing, some to fix rotation handling to match existing code
This functionality will need to be migrated to the new FAST_ModLin module
Previously these functions required the whole Turbine structure to be passed in, which was a holdover from the original mesh getting functions
…because Jacobian perturbations would make it fail. Clamp value instead. Only for fixed bottom cases
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR will be merged once OpenFAST 4.0 is released.
TODO:
openfast-libraryFeature or improvement description
Tight coupling introduces a shared solver around structural modules, based on generalized alpha method, while leaving the remaining modules loosely coupled. The goal of the tight coupling algorithm is to improve computational performance by allowing significantly larger time steps while resolving the time domain structural dynamics
Related issue, if one exists
Impacted areas of the software
The majority of the code in
openfast-libraryhas been reworked to support the tight-coupling algorithm and streamline the process of linearization. The concept of module variables was introduced and a new function and associated data structures were added to each module to specify the global variables and Jacobian matrices contributed.Two existing features are incompatible with this version: Yaw Friction and HSS brake. This will be remedied in a future PR and an issue has been created to track their progress.
Additional supporting information
Test results, if applicable
Due to significant changes in the solution algorithm, all of the regression test results were sufficiently different to require creating new baseline files. However, the results from each test were manually evaluated against prior baselines and found to be acceptable.