Blade surface flow visualization method based on HSV mode

Abstract

The invention belongs to the technical field of wind power generation experiments, and particularly relates to a blade surface flow visualization method based on an HSV mode. The method comprises thefollowing steps: step 1, uniformly adhering red silk threads to the suction surface of a blade; step 2, performing multi-angle photographing on the running blade by using a camera; step 3, detecting the color of the picture by adopting an HSV mode to realize automatic identification of the silk threads; and step 4, selecting the qualified photos through screening for statistical analysis to realize visualization of the blade surface flow field. The swinging angle of the silk threads on the surface of the blade can be observed very visually, and the flowing condition of the surface of the bladeis reflected. The HSV mode is adopted, probability distribution statistics can be carried out according to the swing angle of the silk threads on the surface of the blade, a flow separation intervalis given, and a cloud picture is printed for display so that a visual experiment of a wind power plant outfield flow field is realized.

Description

technical field [0001] The invention belongs to the technical field of wind power generation experiments, and in particular relates to an HSV mode-based visualization method for blade surface flow. Background technique [0002] Wind energy is a clean and renewable resource. Therefore, wind power generation technology has developed rapidly in my country in recent years. As the main technical means of wind turbine research, wind tunnel experiment has been unanimously recognized for its research accuracy. In wind tunnel experiments, the advantages and importance of flow field visualization are increasingly highlighted. [0003] The oil film method and the silk thread method are two reliable flow display technologies. The oil film method uses oil with a certain viscosity to evenly spread on the surface of the test model. During the blowing experiment, under the friction of air, the distribution of the oil film will change to a certain extent, showing a trace similar to the fri...

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Problems solved by technology

However, the oil film method has the following limitations: the oil film method is mostly used for wind tunnel experiments on small flat cascades; due to the long blades of the wind turbine, the linear speed of blade rotation varies greatly

However, the current traditional silk thread experiment scheme has not mastered the technology of visualizing the flow field through the thread, and cannot accurately display the information of the flow field on the surface of the blade through the thread. Considering the unsteady effect of the actual flow, the thread presents a swing within a certain angle range , it is necessary to carry out the probability average of the angle of the silk thread to obtain the average deviation angle of the local silk thread from the mainstream direction, and pass a certain transition or separation standard to judge whether the local flow has a transition or separation

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