Wind erosion particle starting wind speed testing device, testing system and testing method for wind tunnel

Abstract

The invention discloses a wind erosion particle starting wind speed testing device for a wind tunnel, a testing system and a testing method. The wind erosion particle starting wind speed testing device comprises a sand table (1), a plurality of mutually separated test units are arranged on the sand table, each test unit comprises a sand laying section, a contraction section, a shooting channel (8) and a sand grain capturing groove (2) which are sequentially arranged in the wind direction, the sand laying section is used for laying experimental sand, and the contraction section is used for laying experimental sand. The widths of the sand laying section, the contraction section and the shooting channel (8) are sequentially reduced, a shooting area (5) corresponding to the miniature high-speed camera (4) is arranged in the shooting channel (8), the sand grain trapping groove (2) is provided with a V-shaped groove bottom, and sand grain identification areas (3) are distributed at the V-shaped groove bottom. Compared with a single method for measuring the starting wind speed in the prior art, the device and the method are more standard, objective and accurate, the defects and problems encountered in various measuring methods at present are basically solved, and a scientific and practical novel device and a novel method are provided for accurately defining the starting wind speed of the sand grains in the wind tunnel.

Description

technical field [0001] The invention belongs to the technical field of particle starting wind speed measurement in wind-sand flow, and particularly relates to a wind-eroded particle starting wind speed testing device, a testing system and a testing method for wind tunnels. Background technique [0002] In the study of wind-sand physics, the generation mechanism of wind-sand, that is, the starting mechanism of sand particles under the action of wind field, is a fundamental and important research topic. The process of the surface sand particles moving away from the surface under the action of the wind field is called the starting of sand particles, which marks the beginning of surface wind erosion. Wind erosion is one of the main driving forces for land degradation in arid and semi-arid desert regions. The key factor affecting wind erosion, therefore, the starting wind speed of sand particles has been highly concerned by researchers, and it has basic significance for the study...

AI Technical Summary

Problems solved by technology

[0011] The working principle of the fork-type photoelectric sensor is that when the moving sand blocks the direct laser light, the trigger light will light up, but in actual use, it is found that only when a large number of wind-eroded sand particles leap through, can the slender laser light be blocked. The trigger light will only light up when the engine is turned on, so it is not suitable for the situation where only a small amount of sand passes through at the moment of starting

[0012] In addition, in the wind tunnel simulation experiment of starting wind speed, it is often necessary to measure the starting wind speed values ​​of several different sediments or the same sediment but different particle sizes. Traditionally, only one kind of particle starting experiment can be done before the next one. Kind of

For the impact start experiment, since the falling amount of sand particles in the sand supply device cannot be completely uniform, the supply of impact particles cannot be completely consistent in each group of experiments, resulting in a large deviation in the final result of the impact start wind speed;

[0013] The above analysis shows that there are certain defects in the various methods currently used in measuring the starting wind speed, which cannot objectively and accurately measure the starting wind speed value of wind-eroded sand particles.

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