Modelling lidar volume-averaging and its significance to wind turbine wake measurements: Paper

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Abstract

Lidar velocity measurements need to be interpreted differently than conventional in-situ readings. A commonly ignored factor is “volume-averaging”, which refers to lidars not sampling in a single, distinct point but along its entire beam length. However, especially in regions with large velocity gradients, like the rotor wake, can it be detrimental. Hence, an efficient algorithm mimicking lidar flow sampling is presented, which considers both pulsed and continous-wave lidar weighting functions. The flow-field around a 2.3 MW turbine is simulated using Detached Eddy Simulation in combination with an actuator line to test the algorithm and investigate the potential impact of volume-averaging. Even with very few points discretising the lidar beam is volume-averaging captured accurately. The difference in a lidar compared to a point measurement is greatest at the wake edges and increases from 30% one rotor diameter (D) downstream of the rotor to 60% at 3D.
Original languageEnglish
Title of host publicationWake Conference 2017
Number of pages10
Volume854
Publication date2017
Article number012014
DOIs
Publication statusPublished - 2017
EventWake Conference 2017 - Visby, Sweden
Duration: 30 May 20171 Jun 2017
http://standupforwind.se/wake-conference-2017/

Conference

ConferenceWake Conference 2017
CountrySweden
CityVisby
Period30/05/201701/06/2017
Internet address
SeriesJournal of Physics: Conference Series
ISSN1742-6596

Keywords

  • Applied fluid mechanics
  • Wakes
  • General fluid dynamics theory, simulation and other computational methods
  • Wind power plants
  • Optical radar
  • Power and plant engineering (mechanical engineering)
  • Fluid mechanics and aerodynamics (mechanical engineering)
  • Mechanical components
  • Measurement
  • CW radar
  • flow simulation
  • optical radar
  • rotors (mechanical)
  • velocity measurement
  • wakes
  • wind turbines
  • LIDAR volume-averaging modelling
  • wind turbine wake measurement
  • LIDAR velocity measurement
  • lidar flow sampling
  • pulsed lidar weighting functions
  • continous-wave lidar weighting functions
  • detached eddy simulation
  • rotor diameter
  • power 2.3 MW

Activities

  • 1 Conference presentations

Modelling lidar volume-averaging and its effect on wake measurements

Alexander Raul Meyer Forsting (Speaker)

30 May 20171 Jun 2017

Activity: Talks and presentationsConference presentations

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