Large Eddy Simulations and Theoretical Analysis of Wind Turbine Aerodynamics Using an Actuator Line Model

computational fluid dynamics;wind energy;large eddy simulations;actuator line model;Mechanical Engineering

Martinez, Luis A.Meneveau, Charles V. ;

Johns Hopkins University

关键词: computational fluid dynamics;    wind energy;    large eddy simulations;    actuator line model;    Mechanical Engineering;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/44708/MARTINEZ-DISSERTATION-2017.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

The actuator line model (ALM)is a widely used tool to represent the wind turbine bladeswhen performingnumericalsimulations offlow over wind turbines and wind farms.The ALM is used to represent wind turbineblades without the need to resolve the full geometry of the blades.In this work, the ALM is implemented in a large-eddy simulation (LES) research codeand compared with 3 othernumerical codes in the wind energy community.Excellent agreement is observed in the implementation ofthe ALM amongst all the codes.Comparisons against experimental measurements are also performed.From the experimental comparisons, it is found that in the caseof a small scale wind tunnel experiment,a nacelle and tower models are requiredto match the near wake.After the comparisons with other codes andexperiments, a new theoretical approach is used toimprove the ALM.In the ALM, the parameter $epsilon$ establishesthe width over which body forces are distributed.An optimal $epsilon_{m opt}$ is foundbased on two dimensional aerodynamics.This optimal body force is then tested in a three dimensionalsimulation of a wind turbine under uniform inflow.The optimal body force is able to resolve the tip vortexand the tip losses are well reproduced.Then, a new theoretical framework is developed topredict the behavior near the tip in the ALM.This framework can be used to predict the tiplosses for a given body force width $epsilon$and to correct them based on the optimal $epsilon_{m opt}$.Thisimproved ALMhas ability tobetter predict thequantities alongthe blades suchas lift and dragforces, and thuscan providebetter powerpredictions fromthe rotor.