Method for calculating turbulence intensity of tail flow of wind turbine

Abstract

The invention discloses a method for calculating the turbulence intensity of the tail flow of a wind turbine. The method comprises the following steps: calculating a flow direction turbulence intensity vertical direction distribution type of inflow, a wake flow radius at any flow direction cross section position of a wake flow area and maximum additional turbulence intensity generated by a wake flow effect based on basic data such as inflow wind resource information and wind turbine generator characteristic parameters; calculating the additional turbulence intensity and the 'inhibition' turbulence intensity of the wake flow area position; and calculating the flow direction turbulence intensity of any position of the tail flow of the wind turbine based on the steps. According to the method, the flow direction turbulence intensity of any spatial position can be predicted with high precision, especially the 'double-peak' distribution of the near wake flow turbulence intensity and the 'turbulence weakening' effect of the near ground position, and the prediction precision is superior to that of a numerical simulation result based on computational fluid mechanics. And an accurate and efficient turbulence calculation tool is provided for wind turbine design and wind power plant unit layout optimization in a wind engineering project.

Description

technical field

[0001] The invention belongs to the technical field of new energy wind power generation, and in particular relates to an accurate and fast calculation method for wake turbulence intensity of a wind turbine, which can be used for wind engineering projects such as wind turbine design and wind farm micro site selection. Background technique

[0002] After the wind flows through the wind turbine, it forms a wake downstream, and then expands and meanders longitudinally and vertically, and finally dissipates in an almost chaotic manner. The wake structure of wind turbines is complex, including multi-scale coupled vortex systems such as blade tip vortex, blade root vortex, and hub vortex, resulting in severe airflow disturbance and increased turbulence intensity in the wake area. Turbulence intensity is an important factor affecting the fatigue load and ultimate load of wind turbines, and has become one of the important parameters of IEC61400-1 wind turbine safety c...

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