The TurbSim stochastic inflow turbulence code 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 (YawDyn, 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.

The TurbSim code supports all of the features found in the previous SNLWIND-3D¹ and SNwind² inflow turbulence simulator codes 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 the TurbSim code. 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.

The TurbSim code 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.

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 Change Log (v1.50, 42 KB, 25-September-2009)

  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, 355 KB, 02-May-2007)

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

• TurbSim User's Guide (v1.50, 6.6 MB, 25-September-2009)

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

• TurbSim Archive (v1.50, 9.1 MB, 25-September-2009)

  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 10.1.024. The archive also includes a TurbSim executable file for 64-bit Windows® platforms. It was created with Intel® Visual Fortran 10.1.021.

• TurbSim Coherent Structures Archive (247.1 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 AeroDyn.  It runs on all 32-bit Windows® platforms. You will need these files in order to generate coherent structures in TurbSim.

If you want to refer to the TurbSim website in a report, here is a reference you can use:

NWTC Design Codes (TurbSim by Neil Kelley, Bonnie Jonkman).  http://wind.nrel.gov/designcodes/preprocessors/turbsim/.  Last modified 25-September-2009; accessed 25-September-2009.