Mass conservation-based two-dimensional far-field wake flow analysis model

A technology of mass conservation and analytical models, applied in special data processing applications, instruments, electrical digital data processing, etc., can solve problems affecting the accuracy of calculation results, etc.

Active Publication Date: 2018-09-07
NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, it is unrealistic to assume only one velocity profile in the entire wake region, which may affect the accuracy of calculation results

Method used

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  • Mass conservation-based two-dimensional far-field wake flow analysis model
  • Mass conservation-based two-dimensional far-field wake flow analysis model
  • Mass conservation-based two-dimensional far-field wake flow analysis model

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Example 1: Select as figure 1 For the control volume shown, the self-similar speed loss of the LES results in different tip speed ratios and different examples is as follows figure 2 shown.

[0038] An application of a two-dimensional analytical model of far-field wake based on mass conservation, comprising the following steps:

[0039] Step 1: Determine the reference coordinate system, take the center of the wind rotor as the coordinate origin, the rotation axis of the wind rotor is the x-axis (parallel to the incoming flow direction), the radial direction (perpendicular to the incoming flow direction) is the y-axis, and the vertical direction is the z-axis ;

[0040] Step 2: According to the incoming wind speed, compare the curve of the thrust coefficient of the unit with the wind speed to obtain the thrust coefficient C of the unit under this working condition T ;

[0041] Step 3: Determine the value range of the downstream wake boundary coefficient J by analyzi...

Embodiment 2

[0048] Embodiment 2: In this embodiment, the variation of the maximum velocity loss in the horizontal direction with the downstream distance and the distribution of the velocity loss in the vertical wake area are calculated, and the results of the two-dimensional analytical model of the far-field wake are compared with the wind tunnel experimental data, The LES results are compared with other analytical wake models, including the following steps:

[0049] Step 1: Table 1 shows the specific parameters of the wind tunnel experimental data (case 1) and LES results (case 2-5), including the rotor diameter d 0 , hub height z h, wind speed U at hub height hub , thrust coefficient C T , surface roughness z 0 and the ambient turbulence intensity I 0 .

[0050] Step 2: Within the value range of J, take J=1.12 as an example for calculation. At this time, in cases 1-5, the wake expansion coefficients k are: 0.0519, 0.1267, 0.0977, 0.078 and 0.0781.

[0051] Step 3: In order to calc...

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Abstract

The invention discloses a mass conservation-based two-dimensional far-field wake flow analysis model. The two-dimensional far-field wake flow analysis model is established through the following stepsof: 1, classifying wind turbine generator wake flows into a pressure recovery area and a far-field wake flow area, wherein the speed loss of the pressure recover area is in hood distribution and the speed loss of the far-field wake flow area is in Gaussian distribution; solving a maximum speed loss at a position x at the downstream according to a mass conservation equation and distribution characteristics, in the pressure recovery area and the far-field wake flow area, of the speed losses; 3, assuming wake flow linear expansion, defining a wake flow boundary, and importing a wake flow expansion coefficient k to express a linear expansion law of the wake flow area; and 4, calculating a speed loss at any position in the whole wake flow area, and establishing a two-dimensional analysis wind speed distribution calculation model for wind turbine generator far-field wake flows.

Description

technical field [0001] The invention relates to the technical field of wind turbine wake calculation technology, in particular to a two-dimensional analysis model of far-field wake based on mass conservation. Background technique [0002] The analytical wake model is one of the common methods to study the wake of wind turbines. The existing analytical wake models are all based on different principles and assumptions. For example, the most classic Jensen model is based on the assumptions of mass conservation and top-hat distribution, while the Frandsen model is based on the assumptions of momentum theorem and top-hat distribution. There are also some analytical models that improve calculation accuracy by considering the velocity profile in the wake region. For example, the Ishihara model and the BP model are both based on the momentum theorem and the assumption of a self-similar Gaussian distribution of velocity loss in the wake region. However, no matter whether the self-si...

Claims

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Application Information

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IPC IPC(8): G06F17/50
CPCG06F30/17Y02E60/00
Inventor 葛铭纬武英刘永前李莉邵振州
Owner NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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