Method of Measuring Surface Roughness of Wind Field Using Fractal Dimension

Abstract

The invention discloses a wind field surface roughness measuring method by using the fractal dimension. The method comprises the steps: collecting wind speed time series information at a plurality of locations with the known surface roughness rj; calculating the average wind speed; obtaining (img file='DDA0001203750850000011.TIF' wi='139' he='79' / ) information; then using the structural function method to find the fractal dimension Dij of the wind speed time series; obtaining (img file='DDA0001203750850000012.TIF' wi='235' he='70' / ); fitting the obtained (img file='DDA0001203750850000013.TIF' wi='219' he='71' / ) scatter to obtain the relationship (img file='DDA0001203750850000015.TIF' wi='214' he='71' / ) of the surface roughness rj, the average wind speed (img file='DDA0001203750850000014.TIF' wi='43' he='55' / ) and the fractal dimension Dij; collecting the wind speed time series at the location where the surface roughness is measured; finding (img file='DDA0001203750850000016.TIF' wi='161' he='55' / ); obtaining the measured surface roughness r according to the fitting relationship. The wind field surface roughness measuring method by using the fractal dimension has the advantages that the result accuracy of the measured surface roughness can be ensured, and the measurement effort is significantly reduced.

Description

technical field [0001] The present invention relates to the technical field of wind turbines, specifically a method for measuring wind field surface roughness by using fractal dimensions to obtain the fractal dimension by using the fractal method to analyze the wind speed time series, and then obtain the surface roughness of the wind field according to the corresponding relationship . Background technique [0002] Surface roughness represents the roughness of the earth's surface and is a characteristic parameter with the dimension of length. Aerodynamic roughness does not only refer to the roughness of the surface of the object, but is mainly a comprehensive mechanical parameter that points out the influence of the surface of the object on the flowing fluid from the perspective of fluid mechanics. The ground roughness in the aerodynamic sense represents the interaction between the ground surface and the atmosphere, reflecting the reduction effect of the ground surface on wi...

AI Technical Summary

Problems solved by technology

[0004] When determining the surface roughness of a certain area, the usual methods require on-the-spot measurement of building heights or topographic surveys. According to the principle of division, the height distribution of buildings or terrain in the area is statistically measured to calculate the surface roughness. These methods require a lot of Human and material resources

[0005] At present, there is no description or report of the similar technology of the present invention, and no similar data at home and abroad have been collected yet.

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