A stochastic, full-field, turbulence simulator primarialy for use with InflowWind/AeroDyn-based simulation tools

by Neil Kelley and Bonnie Jonkman
National Wind Technology Center

The TurbSim stochastic inflow turbulence tool has been developed to provide a numerical simulation of a full-field flow that contains coherent turbulence structures that reflect the proper spatiotemporal turbulent velocity field relationships seen in instabilities associated with nocturnal boundary layer flows and which are not represented well by the IEC Normal Turbulence Models (NTM). Its purpose is to provide the wind turbine designer with the ability to drive design code (e.g., FAST or MSC.Adams®) simulations of advanced turbine designs with simulated inflow turbulence environments that incorporate many of the important fluid dynamic features known to adversely affect turbine aeroelastic response and loading.

TurbSim supports all of the features found in the previous SNLWIND-3D1 and SNwind2 inflow turbulence simulation tools that had their roots in Paul Veers' original stochastic wind simulator, SNLWIND3. All of the spectral models available in SNLWIND-3D (SMOOTH, WF_UPW, WF_07D, and WF_14D) as well as those available in SNwind (the IEC Kaimal and von Karman Normal Turbulence Models (NTM)) are included in TurbSim. In addition, two new spectral models, NWTCUP and GP_LLJ, have been added to TurbSim. The NWTCUP model is based on conditions observed at the National Wind Technology Center (NWTC); the GP_LLJ model is based on conditions associated with Great Plains low-level jet streams. TurbSim is more efficient than its predecessors in terms of both CPU and memory usage.

TurbSim provides the ability to efficiently generate randomized coherent turbulent structures that are superimposed on the more random background turbulent field as produced by one of the diabatic (non-neutral) spectral models; i.e., GP_LLJ, NWTCUP, SMOOTH, WF_UPW, WF_07D, or WF_14D. Modeled as a combination of non-homogenous Poisson and Lognormal Stochastic Processes, the randomized scaling of the coherent structures in this version of TurbSim are based on measurements derived from the Lamar 120-m tower used as part of the Lamar Low-Level Jet Project (LLLJP) when the GP_LLJ or SMOOTH models are specified. The NWTCUP model uses scaling derived from measurements taken from the 5-sonic anemometer array upwind of the NWTC ART Turbine as part of the Long-Term Inflow and Structural Testing (LIST) Program, and the three wind farm models (WF_UPW, WF_07D, and WF_14D) use scaling derived from measurements taken from upwind, within, and downwind of a large wind farm in San Gorgonio Pass, California.

In version 1.06.00, TurbSim was extended to model turbulence in water. The TIDAL spectral model, which simulates turbulence in a tidal channel, is based on measurements taken near Marrowstone Island in Puget Sound Washington.

  1. Kelley, N.D. (November 1992). Full Vector (3-D) Inflow Simulation in Natural and Wind Farm Environments Using an Expanded Version of the SNLWIND (Veers) Turbulence Code. NREL/TP-442-5225. Golden, CO: National Renewable Energy Laboratory.
  2. Buhl, M.L. Jr. (October 2001). SNwind User's Guide. NREL/EL-500-30121. Golden, CO: National Renewable Energy Laboratory.
  3. Veers, P.S. (March 1988). Three-Dimensional Wind Simulation, SAND88-0152. Albuquerque, NM: Sandia National Laboratories.

You may download the following files from our server:

TurbSim Documentation:

  • TurbSim Change Log (v1.06.00, 44 KB, 3-October-2012)

    This is a list of changes made to the code. Look at this text file to see if we've made worthwhile changes since you received your previous version of TurbSim.

  • TurbSim Overview (v1.21, 363 KB, 25-September-2012)

    This is an overview of TurbSim features. Please refer to it when trying to understand what the program does.

  • TurbSim User's Guide (v1.06.00, 6.6 MB, 25-September-2012)

    This is the TurbSim User's Guide. Please refer to it when trying to understand how the program works.

TurbSim Archives:

  • TurbSim Archive (EXE 9.5 MB) (v1.06.00, 9.5 MB, 30-May-2013)

    This is a self-extracting archive of TurbSim. It contains the TurbSim executable file, sample input file, installation-verification test procedure, change log, source code, and user's guide. It runs on all 32-bit Windows® platforms. We created the executable file with Intel® Visual Fortran Compiler XE [IA-32]. The archive also includes a TurbSim executable file for 64-bit Windows® platforms. It was created with Intel® Visual Fortran Compiler XE [Intel® 64]. The code is compiled with NWTC Subroutine Library v1.04.01.

  • TurbSim Coherent Structures Archive (EXE 259.1 MB) (18-May-2005)

    This is a self-extracting archive of TurbSim coherent structures. It contains the event definition files for both LES and DNS structure types as well as the associated binary data that is used to add coherent structures to background turbulence in InflowWind. It runs on all 32-bit Windows® platforms. You will need these files in order to generate coherent structures in TurbSim.

  • TurbSim Alpha Version (June 2016)

    This is a link to the latest alpha version of TurbSim. Major additions include (1) the ability to generate full-field winds based on measured time series, (2) the ability to specify a desired coherence model for each wind component, (3) API (Frøya) spectral model, and (4) more documentation of previously hidden features like user-defined spectra, user-defined wind profiles, and the user-defined von Karman spectral model. Documentation for this version is incomplete.

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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 (TurbSim).  https://nwtc.nrel.gov/TurbSim. Last modified 14-June-2016 ; Accessed 23-February-2017