WITSEG sampler: a segmented sand sampler for wind tunnel test

摘要

The flux profile of blowing sand is the reflection of a large number of sand particles moving in different trajectories. To describe the function of the flux profile requires measuring the flux of blown sand at different heights. A segmented sand sampler for wind tunnel study (WITSEG sampler) has been designed and evaluated in a wind tunnel. The sampler is 0.6 m high and sectioned into 60 openings that can measure the flux profile of blowing sand at 10-mm intervals. Special attention was paid in designing the sampler to its practicability and efficiency. For the convenience of use, the leading edge with inlets, sand chambers and side cover are removable. To maximize the sampling efficiency, the leading edge is wedge-shaped so that the width of the inlets is 5 mm, while the width of the sand chamber is 15 mm. Each sand chamber has two screened vents that are connected to a vertical vent to minimize the air pressure inside the sand chamber and maximize its efficiency. Wind tunnel evaluation shows that the sampler is good for measuring aeolian sand flux. Both the measured flux profile and total flux show a reasonably good agreement with the widely accepted flux profile function and sand transport equation. It has an overall efficiency of 0.91. The WITSEG sampler that can measure the detailed variation of blown sand flux with height proves to be a good tool for studying the flux profile of blowing sand.