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Comparison between simplified load spectra in accordance with Germanische Lloyd guidelines, and load spectra derived from time domain simulations

Abstract

The Germanische Lloyd guideline allows calculations of load spectra in two fundamentally different ways. In the case of the so-called `simplified load spectra` the maximum amplitude of fluctuation of a load component is formed as {+-}75% of the average value of the purely aerodynamic loads of this component at rated wind conditions, together with an overlay of mass-related loads. The second method allowed in the GL guideline is the calculation of load spectra from simulation results in the time domain. For a number of average wind speeds the time-dependent characteristics of the load components are calculated taking account of the natural spatial turbulence of the wind. These are converted into load spectra using the rainflow method. In a parametric study the load spectra are calculated according to both methods and compared. The calculations are performed for turbines with rated powers of 100 kW to 2000 kW, with two and three blades, and also for stall-controlled and pitch-controlled turbines. The calculated load spectra are compared with each by means of 1 P fatigue equivalent load spectra. The influence of individual parameters is presented, as is the validity of the simplified load spectra. (au)
Authors:
Rees, M [1] 
  1. Aerodyn Energiesysteme gmbH, Rendsburg (Germany)
Publication Date:
Sep 01, 1996
Product Type:
Conference
Report Number:
NEI-DK-2424; CONF-960267-
Reference Number:
SCA: 170602; PA: DK-96:001562; EDB-96:126084; SN: 96001645492
Resource Relation:
Conference: 11. International Energy Agency (IEA) research and development wind annex, Stuttgart (Germany), 1-2 Feb 1996; Other Information: PBD: 1996; Related Information: Is Part Of IEA Joint Action. Wind turbine fatigue; Maribo Pedersen, B. [ed.]; PB: 108 p.
Subject:
17 WIND ENERGY; WIND LOADS; AERODYNAMICS; TURBINE BLADES; COMPUTERIZED SIMULATION; WIND; TURBULENCE; SPECTRA; POWER RANGE 100-1000 KW; TIME-SERIES ANALYSIS; RECOMMENDATIONS
OSTI ID:
276948
Research Organizations:
Danmarks Tekniske Univ., Lyngby (Denmark). Afd. for Fluid Mekanik
Country of Origin:
Denmark
Language:
English
Other Identifying Numbers:
Other: ON: DE96777162; TRN: DK9601562
Availability:
OSTI as DE96777162
Submitting Site:
DK
Size:
pp. 1-5
Announcement Date:

Citation Formats

Rees, M. Comparison between simplified load spectra in accordance with Germanische Lloyd guidelines, and load spectra derived from time domain simulations. Denmark: N. p., 1996. Web.
Rees, M. Comparison between simplified load spectra in accordance with Germanische Lloyd guidelines, and load spectra derived from time domain simulations. Denmark.
Rees, M. 1996. "Comparison between simplified load spectra in accordance with Germanische Lloyd guidelines, and load spectra derived from time domain simulations." Denmark.
@misc{etde_276948,
title = {Comparison between simplified load spectra in accordance with Germanische Lloyd guidelines, and load spectra derived from time domain simulations}
author = {Rees, M}
abstractNote = {The Germanische Lloyd guideline allows calculations of load spectra in two fundamentally different ways. In the case of the so-called `simplified load spectra` the maximum amplitude of fluctuation of a load component is formed as {+-}75% of the average value of the purely aerodynamic loads of this component at rated wind conditions, together with an overlay of mass-related loads. The second method allowed in the GL guideline is the calculation of load spectra from simulation results in the time domain. For a number of average wind speeds the time-dependent characteristics of the load components are calculated taking account of the natural spatial turbulence of the wind. These are converted into load spectra using the rainflow method. In a parametric study the load spectra are calculated according to both methods and compared. The calculations are performed for turbines with rated powers of 100 kW to 2000 kW, with two and three blades, and also for stall-controlled and pitch-controlled turbines. The calculated load spectra are compared with each by means of 1 P fatigue equivalent load spectra. The influence of individual parameters is presented, as is the validity of the simplified load spectra. (au)}
place = {Denmark}
year = {1996}
month = {Sep}
}