Initial Studies of Low-Order Turbulence Modeling of the Wind Turbine In-Flow Environment

2004 ◽  
Author(s):  
John Spitler ◽  
Scott Morton ◽  
Jonathan Naughton ◽  
William Lindberg
Keyword(s):  
Wind Turbine ◽  
Turbulence Modeling ◽  
Flow Environment ◽  
Low Order

Numerical Simulation of the Aerodynamic Performance of a H-Type Wind Turbine during Self-Starting

2014 ◽  
Vol 529 ◽  
pp. 296-302 ◽  
Author(s):  
Wei Zuo ◽  
Shun Kang
Keyword(s):  
Flow Field ◽  
Wind Turbine ◽  
Pitch Angle ◽  
Turbulence Modeling ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
Time Dependent ◽  
Two Dimensional ◽  
Vertical Axis Wind Turbine ◽  
Sst Turbulence Model

The aerodynamic performance and the bypass flow field of a vertical axis wind turbine under self-starting are investigated using CFD simulations in this paper. The influence of pitch angle variations on the performance of the wind turbine during self-starting is presented. A two-dimensional model of the wind turbine with three blades is employed. A commercial software FlowVision is employed in this paper, which uses dynamic Cartesian grid. The SST turbulence model is used for turbulence modeling, which assumes the flow full turbulent. Based on the comparison between the computed time-dependent variations of the rotation speed with the experimental data, the time-dependent variations of the torque are presented. The characteristics of self-starting of the wind turbine are analyzed with the pitch angle of 0o、-2oand 2o. The influence of pitch angle variations on two-dimensional unsteady viscous flow field through velocity contours is discussed in detail.

Crucial Torsional Modal Identify on Drive-Train in a Wind Turbine

2012 ◽  
Vol 226-228 ◽  
pp. 275-280
Author(s):  
Hui Xin Li ◽  
Fa Ming Wu ◽  
Wen Li ◽  
Dian Wang
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Vibration Isolation ◽  
Rotational Frequency ◽  
Drive Train ◽  
Gear Train ◽  
Horizontal Axis Wind Turbine ◽  
Generator System ◽  
Train Dynamics ◽  
Low Order

The rotational frequency of large scale wind turbine is very low, so low order modal of drive-train in a horizontal-axis Wind turbine generator system (WTGS) needs special attention to avoid structural resonance. In this paper, with Lagrange’s equation, a three-mass drive-train dynamics of WTGS is modeled and analyzed. After comparing with the results by GHbladed4.1 and SIMPACK, we found that those results show little differences clearly. So the drive-train dynamics above is rational and the accurate analyses are fit to identify the crucial low order torsional modal of drive-train rapidly in WTGS. In addition, the anti-resonance frequency of the gear-train found by frequency response method can be very significant for vibration isolation of drive train in the wind turbine system.

Numerical Investigation of Mini Wind Turbines Near Highways

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Caelan Lapointe ◽  
Harish Gopalan
Keyword(s):  
Wind Turbine ◽  
Computer Aided Design ◽  
High Speed ◽  
Turbulence Modeling ◽  
Field Measurements ◽  
Vertical Axis ◽  
Motion Field ◽  
Vertical Axis Wind Turbine ◽  
Highway Traffic ◽  
Vehicle Motion

High-speed vehicle motion on the highways produces localized winds whose energy can be harnessed. These local winds have less variability especially if the highway traffic is constant. The idea of extracting energy from highway winds has been conceptualized in many studies before. However, the feasibility of this idea has never been tested using analytical, computation, or experimental methods. In this study, we numerically compute the amount of power that can be extracted from local highway winds due to vehicular motion. A unsteady Reynolds-averaged Navier–Stokes (URANS) method is used for modeling the atmospheric boundary layer (ABL). Realistic computer-aided design (CAD) models of cars and trucks separated by spacing information obtained from the existing standards are used to model the vehicle motion. A vertical axis wind turbine (VAWT) is used for extracting energy from the wind. The entire framework of ABL, vehicles, and turbine is simulated using overset grids and multiple translating and rotating frames of reference. Many vehicle motion scenarios were compared to the case of an isolated wind turbine. The initial results show a significant increase in the power that can be extracted by these turbines. The average extracted power increases about 317% when compared to the case without any vehicular motion. Field measurements or wind tunnel studies are required to provide validation for the computations and to determine if more advanced turbulence modeling methodologies have to be employed for these studies.

Determination of Wake Propagation Downstream of the Wind Turbine Using Computational Fluid Dynamics

2012 ◽  
Author(s):  
Abolfazl Pourrajabian ◽  
Reza Ebrahimi ◽  
Masoud Mirzaei
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farm ◽  
Turbulence Modeling ◽  
Governing Equations ◽  
Horizontal Axis Wind Turbine ◽  
Velocity Magnitude

A numerical scheme for determination of wake propagation in downstream of a wind turbine was developed by Computational Fluid Dynamics (CFD) and analytical correlation. A 3bladed horizontal axis wind turbine was selected and airflow around the wind turbine was analyzed. The flow was assumed steady state and a pressure based approach was adopted to solve the governing equations in an unstructured grid distribution using parallel processing. In conjunction with governing equations, the kω – SST model was used for turbulence modeling. The formation of the wake behind the wind turbine was estimated and an appropriate equation was derived for velocity magnitude at the downstream of the wind turbine. Moreover, the suitable distances between wind turbines in wind and crosswind directions were estimated. Results show a good agreement between the previous researches and the comparison indicates that the CFD could be considered as a proper tool for determination of wake properties, windward and crosswind distance between wind turbines in a wind farm.

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