Mechanics of particle transport by wind

风输送颗粒的力学

• 批准号: 194492-2009
• 负责人: McKennaNeuman, Cheryl
• 金额: $ 4.66万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=523215
• 关键词: Mechanics; particle; transport; wind

The entrainment and transport of particles by wind occurs on all continents of the Earth. Arid to semi-arid regions are principally affected, although sites disturbed by agriculture, mining and construction activities also are subject to deflation and reduced soil fertility, as well as, poor air quality. Wind erosion in Canada is unique as compared to the hot deserts and grasslands of other countries in the sense that many northern areas affected are seasonally cold and dry, though humid in summer. Similarly, biotic crusts flourish on expansive coastal beaches that are considerably windier than continental deserts. In effect, very little of what scientists currently know about the transport of particles by wind in hot, arid regions well applies to high latitude, cold regions. This research program aims to understand and quantify the degree to which aeolian processes are affected by constraints on the supply of particles from a given surface to the airflow; as for example, the presence of crusts, high humidity, pore ice, and non-erodible roughness elements. The Trent Environmental Wind Tunnel (TEWT) is the only facility in the world at present where the transport of sedimentary particles is studied over a systematically varied range of temperature and humidity, inclusive of winter time conditions. Work in this facility complements that of field scientists, but has the advantage that the time required to study such environmental controls is significantly compressed. Natural wind erosion events are notoriously unpredictable and intermittent, so that it is difficult to carry out field experiments with a high degree of spatial and temporal resolution. Wind tunnel simulation allows researchers to study the underlying physics of the phenomena using particle tracking velocimetry (PTV); as for example, as well as to carry out detailed vertical and horizontal profiling of the turbulent airflow properties. Over the long term, the goal of this research program is to comprehend more fully the range of conditions under which wind erosion occurs on a global scale, and to contribute to improvements in the development and parametrization of existing sediment transport models.

粒子夹住和传输颗粒发生在地球的各大洲。干旱到半干旱地区主要受到影响，尽管受到农业，采矿和建筑活动打扰的地点也会受到通缩和降低的土壤肥力，并且空气质量差。与其他国家的热沙漠和草原相比，加拿大的风侵蚀是独一无二的，因为许多受影响的北部地区都在季节性冷又干燥，尽管在夏季潮湿。同样，生物壳在广阔的沿海海滩上繁荣起来，沿海海滩比大陆沙漠更风。实际上，科学家目前对粒子在热，干旱地区的传输的了解很少，这很好地适用于高纬度地区的冷区。该研究计划旨在理解和量化风格从给定表面到气流的颗粒供应的限制影响的风化过程的程度；例如，地壳的存在，高湿度，孔冰和不可验证的粗糙度元素。 Trent环境风洞（TEWT）是目前唯一在系统的温度和湿度范围内研究沉积物颗粒的运输（包括冬季时间条件）。在该设施中的工作补充了现场科学家的工作，但具有研究这种环境控制所需的时间是显着压缩的。众所周知，自然风侵蚀事件是不可预测的和间歇性的，因此很难以高度的空间和时间分辨率进行现场实验。风洞模拟允许研究人员使用粒子跟踪赛车测定法（PTV）研究现象的潜在物理。例如，以及对湍流特性进行详细的垂直和水平分析。从长远来看，该研究计划的目标是更充分地理解风向在全球范围内发生的条件范围，并有助于改善现有沉积物传输模型的开发和参数化。