Laser Doppler Anemometer (LDA) replacement

激光多普勒风速计 (LDA) 更换

• 批准号: RTI-2023-00076
• 负责人: McKennaNeuman, Cheryl
• 金额: $ 6.31万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=765967
• 关键词: Laser; Doppler; Anemometer; LDA; replacement

The boundary-layer environmental wind tunnel at Trent University (TEWT) was designed and constructed for simulating the transport of particulate matter by wind. Nearing three decades in operation, this facility is a well-established international leader in aeolian transport research. It is the only facility of its type in the world that is equipped to run under full climate control with varied air temperature (-10 deg C to 35 deg C) and relative humidity (3% to 85%). It is capable of simulating, for example, wind erosion on a farm in Lethbridge during a drought; particle emissions from tailings ponds and stockpiles in the arctic at subfreezing temperatures; and seasonal variation in airborne microplastics transport surrounding waste management facilities throughout Canada. The barrier that we currently face is that our LDA processor, which has run almost continuously during operation of the wind tunnel over the last 13 years, is malfunctioning and cannot be repaired by the manufacturer. It urgently needs to be replaced so that we can fulfill our immediate obligations to sustain graduate student training; conduct experiments on microplastics transport in the atmosphere as a Project Partner with NERC funded colleagues in the UK; and remain competitive in obtaining contract work with industry and various public agencies to assess emission rates and controls. Since acquiring the LDA through a CFI grant awarded in 2009, we have used this instrument daily to carry out research supported by $740K in NSERC Discovery Grant funding. Particles under investigation in our lab may include either aerosols that travel over long distances (km) while in suspension, or larger particles with sufficient mass to constrain their motion to low ballistic hops (cm), and/or creep over short distances (mm). These may originate from sources that are either mineral, organic or anthropogenic, but all are well known to influence air quality and human health. In our daily operations we require a Laser Doppler Anemometer (LDA) to measure the kinetics of both the turbulent airflow structure, which entrains and propels the particles of interest, as well as the particle cloud. A non-contact 2D LDA offers many advantages over older technologies in that it samples rapidly and accurately without inducing flow perturbation caused by inserting a bluff body instrument directly in the flow, particularly one that can be destroyed by particle impact. Using this instrument, our lab was first to capture direct synchronous measurements showing that airflows saturated with particulate matter have increased turbulence intensity. Our overarching aim in future work is to assess the effects of a changing climate on the kinetics of aeolian transport systems that exist throughout high latitude, cold climate regions characteristic of Canada. Such work will build on the pivotal contributions of the TEWT lab toward fundamental understanding of particle transport in atmospheric boundary-layer flows.

为了模拟颗粒物在风作用下的输运过程，设计并建造了美国特伦特大学的边界层环境风洞。该设施已运行近30年，是风沙运输研究领域公认的国际领导者。它是世界上唯一一个配备有全气候控制的设施，可在不同的空气温度（-10摄氏度至35摄氏度）和相对湿度（3%至85%）下运行。例如，它能够模拟干旱期间莱斯布里奇一个农场的风蚀;北极地区尾矿池和尾矿库在冰点以下温度下的颗粒排放;以及加拿大各地废物管理设施周围空气中微塑料运输的季节性变化。我们目前面临的障碍是，我们的LDA处理器在过去13年的风洞运行期间几乎连续运行，出现故障，制造商无法修复。它迫切需要被替换，以便我们能够履行我们的直接义务，以维持研究生培训;作为NERC资助的英国同事的项目合作伙伴，进行微塑料在大气中运输的实验;并在与行业和各种公共机构签订合同以评估排放率和控制方面保持竞争力。自2009年通过CFI赠款获得LDA以来，我们每天都使用该仪器进行由NSERC发现赠款资助的74万美元支持的研究。 我们实验室研究的颗粒可能包括悬浮时长距离（km）传播的气溶胶，或具有足够质量的较大颗粒，以将其运动限制在低弹道跳数（cm）和/或短距离（mm）蠕变。这些污染物可能来自矿物、有机或人为来源，但众所周知，它们都会影响空气质量和人类健康。在我们的日常操作中，我们需要一台激光多普勒风速仪（LDA）来测量湍流气流结构的动力学，它夹带并推动感兴趣的颗粒，以及颗粒云。非接触式2D LDA提供了许多优于旧技术的优点，因为它快速准确地采样，而不会引起由直接在流中插入海崖体仪器引起的流扰动，特别是可能被颗粒撞击破坏的钝体仪器。使用这种仪器，我们的实验室是第一个捕获直接同步测量显示，空气流饱和颗粒物增加了湍流强度。我们在未来工作的总体目标是评估气候变化的动力学的风成输送系统，存在于整个高纬度，寒冷的气候地区的特点，加拿大的影响。这些工作将建立在TEWT实验室对大气边界层流动中粒子传输的基本理解的关键贡献之上。