Measurement device and method for moving speed and mass distribution of sand grains of wind-blown sand creeping layer

Abstract

The invention relates to a measurement device and a measurement method for the moving speed and mass distribution of sand grains of a wind-blown sand creeping layer. The measurement device comprises a separation chamber; and the separation chamber is provided with an entrance (205) and a separation wall (4), wherein the entrance (205) is arranged at the top wall of the separation chamber, the separation wall (4) is arranged between the top wall and the bottom wall, the bottom wall is opposite to the top wall, a plurality of separation ports (7) are sequentially and parallelly arranged on the separation wall (4) from top to bottom, and each separation port (7) is connected with a corresponding collection component (8). According to the measurement method for the moving speed and mass distribution of the sand grains of the wind-blown sand creeping layer, supposing that the horizontal distance between the entrance (205) and the separation wall (4) is x0, the vertical distances between the upper end and the lower end of an i-th separation port (7) and the entrance (205) are respectively yi1 and yi2, and then, the velocity range of horizontal initial velocities of the sand grains entering the i-th separation port (7) is expressed by a formula (shown in a drawing).

Description

technical field [0001] The invention relates to a device and a measuring method capable of measuring the speed of movement of sand grains in a blown-sand creeping layer and its mass distribution. The measuring device and the measuring method are especially suitable for field blown-sand observation or wind tunnel experiments. Background technique [0002] China is one of the countries with the most severe wind and sand hazards in the world. In order to effectively prevent and control wind-sand disasters, it is necessary to study the basic laws of wind-sand movement. [0003] The movement of sand particles in wind-blown sand flow includes creep, jump and suspension. Among them, creep is the movement form of sand particles rolling or sliding on the sand bed surface, jump is the movement form of sand particles falling to the sand bed surface under the action of gravity after taking off from the sand bed surface, and suspension is the movement form of sand particles A form of m...

AI Technical Summary

Problems solved by technology

[0005] However, the research methods of Wang et al. (2009) and Zhang Yang et al. (2010, 2011) have shortcomings: the creeping layer has a certain thickness, and the movement of sand particles in the uppermost layer is mainly caused by particle collision and airflow shearing, while the lower layer The movement of sand grains is mainly caused by the friction between grains and the shearing action of airflow, and the movement speed of sand grains in the upper layer is greater than that of the sand grains in the lower layer.

[0006] Therefore, it is difficult to measure the movement parameters of sand grains in the creeping layer by current observation technology, and the accurate measurement of sand grain movement in the creeping layer has become the focus of attention of the aeolian sand science community.

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