摘要
风沙流通量廓线(风沙流结构)是以不同轨迹运动的沙粒在垂直方向上的宏观反映。建立风沙流通量廓线函数需要测定不同高度的输沙率。为此,我们设计了适用于风洞实验的多路集沙仪(WITSEG集沙仪),并通过风洞实验对其进行了检验。WITSEG集沙仪高60cm,由60个进沙口和集沙盒组成,每个进沙口高1cm。该集沙仪可以测量风沙流中60个不同高度的输沙率。在设计WITSEG集沙仪时,着重实用性和集沙效率。为了使用方便,带有进沙口的入口段、集沙盒和保护盖板设计为活动式。为了提高集沙效率,入口段设计成楔形,使得进沙口宽0 5cm,而集沙盒宽度为1 5cm。每个集沙盒留有两个过滤网排气孔,以减小集沙盒内的静压、提高采集效率。风洞实验检验表明,用WITSEG集沙仪测得的风沙流结构和总输沙率与风速的关系与已广泛接受的结论非常一致。WITSEG集沙仪能观测输沙率随高度的详细变化,是研究风沙流结构的较好工具。
The flux profile of a blowing sand cloud is the reflection of blown sand particles moving in different trajectories. To establish the function of the flux profile requires measuring the blown sand flux at different height. A segmented sampler for wind tunnel study (WITSEG Sampler) has been designed and evaluated in a wind tunnel. The sampler is 60 cm high, and sectioned into 60 openings that can measure the flux profile of a blowing sand cloud within 60 different heights at 1cm interval. Special attention is paid in designing the sampler to its practicability and efficiency. For the conveniences of use the leading edge with inlets, sand chambers and side cover are made removable. To maximize the sampling efficiency the leading edge is made wedge\|shaped so that the width of the inlets is 0\^5 cm while the width of the chamber is 1\^5 cm. 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 aeolian sand. Both the measured flux profile and total flux show a reasonably good agreement with the widely accepted results. 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 a blowing sand cloud.
出处
《中国沙漠》
CSCD
北大核心
2003年第6期714-720,共7页
Journal of Desert Research
基金
国家重点基础研究发展规划(973项目G2000048702)资助
关键词
风洞实验
集沙仪
风沙运移
风沙流结构
aeolian transport
sampler
sampling efficiency
flux profile
