D.W. Lobitz, T. D. Ashwill, April 1986, Sandia National Laboratories
Aeroelastic effects impact the structural dynamic behavior of vertical axis wind turbines (VAWTs) in two major ways. First, the stability phenomena of flutter and divergence are direct results of the aeroelasticity of the structure. Secondly, aerodynamic damping can be important for predicting response levels, particularly near resonance, but also for off-resonance conditions. The inclusion of the aero- elasticity is carried out by modifying the damping and stiffness matrices in the NASTRAN finite element code. Through the use of a specially designed preprocessor, which reads the usual NASTRAN input deck and adds appropriate cards to it, the incorporation of the aeroelastic effects has been made...
Brian C. Owens and John E. Hurtado
Texas A&M University, College Station, Texas, 77843, USA
Joshua A. Paquette, Daniel T. Griffith, and Matthew Barone§
Sandia National Laboratories, Albuquerque, New Mexico, 87185, USA April 1986, Sandia National Laboratories
The availability of offshore wind resources in coastal regions makes offshore wind energy an attractive opportunity. There are, however, significant challenges in realizing offshore wind energy with an acceptable cost of energy due to increased infrastructure, logistics, and operations and maintenance costs. Vertical-axis wind turbines (VAWTs) are potentially ideal candidates for offshore applications, with many apparent advantages over the horizontal-axis wind turbine configuration in the offshore arena. VAWTs, however, will need to undergo much development in the coming years. Thus, the Offshore Wind ENergy Simulation (OWENS) toolkit is being developed as a design tool for assessing innovative floating VAWT configurations.
B C Owens and D T Griffith, June 2014, Sandia National Laboratories
A vertical-axis wind turbine (VAWT) rotor configuration offers a potential transformative technology solution that significantly lowers cost of energy for offshore wind due to its inherent advantages for the offshore market. However, several potential challenges exist for VAWTs and this paper addresses one of them with an initial investigation of dynamic aeroelastic stability for large-scale, multi-megawatt VAWTs. The aeroelastic formulation and solution method from the BLade Aeroelastic STability Tool (BLAST) for HAWT blades was employed to extend the analysis capability...
Torben Juul Larsen and Helge Aagaard Madsen, Proceedings of EWEA 2013, European Wind Energy Association, 2013
In this paper a method for an implementation of a 2D actuator cylinder flow model of an Vertical Axis Wind Turbine (VAWT) is presented. The model is implemented in a full aeroelastic code including consideration of structural dynamics, dynamic inflow, tower shadow and dynamic stall, which is needed for a full load analysis relating to eg. certification of a VAWT turbine. Further on, principal load cases according to the IEC61400-1 are simulated for a fictitious 5MW VAWT turbine in it’s simplest 2 bladed Darrieus configuration. The IEC61400-1 load cases, originally developed for Horizontal Axis Wind Turbines (HAWT’s), are discussed regarding the application to VAWT’s. Further on a small section regarding aerodynamic flow in curved motion is included.
Dale Berg, September 2016, Sandia National Laboratories
This slide deck was present to Delft Technical University by Dale Berg who was a principal researcher of the Darrieus type VAWTs that Sandia National Laboratories worked on from the 1970s through the 1990s. It covers the history of Sandia's work on VAWTs including their efforts to develop validated aeroelastic modeling.
David Marten, Matthew Lennie, Georgios Pechlivanoglou, Christian Oliver Paschereit, Norbert Dy, Ion Paraschivoiu, Farooq Saeed, January 2017, Conference Paper - 35th Wind Energy Symposium
The open source simulation code QBLADE, based on a Lifting Line Free Vortex Wake formulation to evaluate the unsteady aerodynamics, recently integrated the PROJECT-CHRONO FEA library that, by using Euler-Bernoulli beams in a corotational formulation, solves for the structural dynamics to achieve an aeroelastic coupling. To validate the newly implemented structural model its performance is compared to literature data and two other structural computer codes. The comparison is based on a modal analysis, steady- and aeroelastic simulations of the SNL 34m VAWT testbed for which the aerodynamic and structural properties are well known. The structural loads are obtained from IEC 61400-1 design load cases. In one of the calculated load cases an aeroelastic instability could be observed which confirms similar observations that have previously been reported in the literature.