Hydrodynamics routines for offshore wind turbine analysis

by Jason Jonkman, Ph.D.
National Wind Technology Center

source code supported by Greg Hayman
National Wind Technology Center

HydroDyn is a time-domain hydrodynamics module that has been coupled into the FAST wind turbine computer-aided engineering (CAE) tool to enable aero-hydro-servo-elastic simulation of offshore wind turbines. HydroDyn is applicable to both fixed-bottom and floating offshore substructures. This latest release of HydroDyn follows the requirements of the FAST Modularization Framework, couples to FAST v8, and provides new capability (relative to prior versions) for modeling the hydrodynamic loading on multi-member substructures. HydroDyn can also be driven as a standalone code to compute hydrodynamic loading uncoupled from FAST.

HydroDyn allows for multiple approaches for calculating the hydrodynamic loads on a structure: a potential-flow theory solution, a strip-theory solution, or a combination of the two. Waves in HydroDyn can be regular (periodic) or irregular (stochastic) and long-crested (unidirectional) or short-crested (with wave energy spread across a range of directions). HydroDyn treats waves using first-order (linear Airy) or first- plus second-order wave theory with the option to include directional spreading, but no wave stretching or higher order wave theories are included. To minimize computational expense, Fast Fourier Transforms are applied in the summation of all wave frequency components.

You may download the following files from our server:


  • Change Log
    This is a list of changes made to the code.
  • HydroDyn Manual (PDF 1.1 MB) (draft version)
    Read this document to learn about the theory implemented in HydroDyn and how to use the software.

HydroDyn Archives (v2.05.00, 13-Apr-2016)

Programming Language:     Technology:     Wind and Water Tools:

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If you want to refer to this website in a report, here is a reference you can use:
NWTC Information Portal (HydroDyn).  https://nwtc.nrel.gov/HydroDyn. Last modified 14-April-2016 ; Accessed 05-April-2020