Saarblitz, Wind farm in HDR,, creative commons by-nc-sa 2.0


HAWC2 (Horizontal Axis Wind turbine simulation Code 2nd generation) is an aeroelastic code intended for calculating wind turbine response in time domain. HAWC2 has been used in numerous research projects and industrial applications. The code has been verified through measurements and comparisons with other codes. It has been used to simulate more than 100 different wind turbines. The HAWC2 has many significant features, particularly related to design and load simulation of large wind turbines in multi MW size. HAWC2 has also been extended for calculating on Vertical Axis Wind Turbines (VAWT).

The core of the code was developed mainly within the years 2003-2007, by the Aeroelastic Design Research Program at DTU Wind Energy, DTU Risø Campus in Denmark. HAWC2 is developed and distributed by DTU Wind Energy and has been used in numerous research projects and industrial applications. HAWC2 has a large number of users and is used both for design and verification purposes.

HAWC2 is able to simulate wind turbines in time response with following properties:

  • Normal onshore with 1,2, 3 or more blades
  • Vertical Axis Wind Turbines (VAWT)
  • Pitch and (active) stall controlled wind turbines
  • Guyed support structures
  • Offshore turbines on monopoles, tripods or jackets
  • Floating turbines with mooring lines
  • Multiple rotors in one simulation
  • Multibody formulation that can handle multiple degrees of freedom (like blade torsion)
  • Structural beam element based on an anisotropic fully populated stiffness matrix (BECAS output data).
  • Detailed aerodynamic BEM model for HAWT  that includes:
    • Dynamic stall models: Stig Øye model, a modified Beddoes-leishmann model and a model for ATEF (Active Trailing Edge Flaps)
    • Skew inflow model
    • Shear effects on the induction
    • Dynamic inflow model
    • Aerodynamic 2D actuator cylinder model for VAWT
    • High fidelity aerodynamics by a SFI (structure-fluid interaction) coupling to the CFD code EllipSys3D
    • Hydrodynamic model based on Morrison’s equation, WAMIT or McCamy & Fuchs.
    • Water Kinematics that includes:
    • Currents
    • Linear airy waves
    • Irregular airy waves
    • Deterministic irregular waves
    • Stream function wave
    • Wind, turbulence and wake models:
    • Build-in Mann turbulence generator (Fully coherent 3D-turbulence)
    • Able to read Mann turbulence model from the WAsP engineering
    • Able to read Veers turbulence model (used in FLEX5)
    • Dynamic wake meandering model
    • Default controller provided with a pitchregulated variable speed controller
    • Coupling of external systems like Mooring lines, WAMIT etc.
    • Soil module consisting of a set of spring-damper forces attached to a main body.
    • Eigenvalue analysis at standstill

Latest version


Submitted by Anders Yde on August 24, 2015 - 2:00pm
Main hypothesis
HAWC2 consists of models describing the external effect, applied loads, structural dynamics and connection to the control system. The external effects models how the wind, waves and soil is expected to behave. The applied loads models how the external effects interact with the structure through aerodynamic, hydrodynamic and soil models. The structural formulation of HAWC2 is based on a multibody system. This enables a wide range of model capabilities and the possibility to include non-linear geometric effects. Wind turbine control is preformed through external DLL´s (Dynamic Link Library) that operates the system under different conditions.
Newmark beta solution scheme together with Newton-Raphson iterations within each time-step
Structural dynamics
Turbulence closure
Turbulence model
Mann turbulence generator (Fully coherent 3D-turbulence) , Able to read Veers turbulence model , RANS & LES by SFI (structure-fluid interaction) coupling to the CFD code EllipSys3D
Mooring lines
Structural dynamics
Added mass coefficient
Normal drag coefficient
Tangential drag coefficient
Seabed contact model
Seabed-line friction model
Wave kinematics
Wave theory
The wave kinematics are not calculated within the HAWC2 code, but provided externally through a defined DLL (Dynamic Link Library) interface, where the present open source DLL includes the water kinematics. The water kinematics includes : Currents, Linear airy waves, Irregular airy waves, Deterministic irregular waves, Stream function wave, Able to read pre-generated water kinematics
Free surface correction
Wheeler stretching method
Wave spectrum
JONSWAP and Pierson–Moskowitz spectrum

[1] Larsen, TJ and Hansen, AM (2012) ”How to HAWC2, the user’s manual”, Technical Report Risø-R-1597(ver.4-3) (EN), DTU Wind Energy, Roskilde, Denmark

[2] Hansen MH., Gaunaa M. and Madsen HA. (2004) A Beddoes–Leishman type dynamic stall model in state-space and indicial formulations. Risø National Laboratory, Risø-R-1354(EN).

[3] Hansen, M. H. (2007), Aeroelastic instability problems for wind turbines. Wind Energ., 10: 551–577. doi: 10.1002/we.242

[4] Jaint A, Robertson AN, Jonkman JM, Goupee AJ, Kimball RW, Swift AHP (2012). FAST Code Verification of Scaling Laws for DeepCwind Floating Wind System Tests. 22nd International Offshore and Polar Engineering Conference, Rhodes, Greece, June 17-22

[5] Kim, T and Hansen, AM and Branner, K (2013) “Development of an anisotropic beam finite element for composite wind turbine blades in multibody system”, Renewable Energy, 59, 172-183, ISSN 0960-1481.

[6] Kim, T., Larsen, TJ. and Yde, A. (2014), Investigation of potential extreme load reduction for a two-bladed upwind turbine with partial pitch. Wind Energ. doi: 10.1002/we.1766

[7] Larsen, TJ, Madsen, HA, Larsen, G and Hansen, KS (2013) ”Validation of the Dynamic Wake Meander Model for Loads and Power Production in the Egmond aan Zee Wind Farm”, Wind Energ., 16, 605–624. DOI: 10.1002/we.1563.

[8] Leishman JG and Beddoes TS. (1986) A generalized model for airfoil unsteady aerodynamic behaviour and dynamic stall using the indicial method. Proc. of the 42nd Annual Forum of the American Helicopter Society

[9] Madsen, H. Aa., Riziotis, V., Zahle, F., Hansen, M.O.L., Snel, H., Grasso, F., Larsen, T.J., Politis, E. and Rasmussen, F. (2012), Blade element momentum modeling of inflow with shear in comparison with advanced model results. Wind Energ., 15: 63–81. doi: 10.1002/we.493

[10] Madsen HA, Riziotis V, Zahle F, Hansen MOL, Snel H, Grasso F, Larsen TJ, Politis E. and Rasmussen F. (2011) “BEM blade element momentum modeling of inflow with shear in comparison with advanced model results.” Wind Energ.; 15: 63–81. DOI:10.1002/we.493.

[11] Popko W, Vorpahl F, Zuga A, KohlmeierM, Jonkman J, RobertsonA, Larsen TJ, Yde A, Sætertrø K, Okstad KM, Nichols J, Nygaard TA, Gao Z,Manolas D, KimK, Yu Q, Shi W, Park H, Vásquez-Rojas A, Dubois J, Kaufer D, Thomassen P, de Ruiter MJ, Peeringa JM, Zhiwen H, von Waaden H. (2012) Offshore code comparison collaboration continuation (OC4), phase I —results of coupled simulations of an offshore wind turbine with jacket support structure. Proceedings of the 22nd International Society of Offshore and Polar Engineers Conference, Rhodes, Greece, June 17-22.

[12] Vorpahl F, Strobel M, Jonkman JM, Larsen TJ, Passon P, Nichols J. (2013). Verification of aero-elastic offshore wind turbine design codes under IEA wind task XXIII. Wind Energ.; DOI:10.1002/we.1588.

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