Wind Tunnel Tests of the Airborne PVM-100A Response to Large Droplets
Wind Tunnel Tests of the Airborne PVM-100A Response to Large Droplets
复制标题
机载 PVM-100A 对大液滴响应的风洞测试
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
J. Strapp
中科院分区：
文献类型：
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作者：
M. Wendisch;T. Garrett;J. Strapp
格柏科技有限公司粒子体积监测仪（Particle Volume Monitor， PVM）被广泛用于测量水云的液态水含量（LWC）和水滴有效半径（reff）。该仪器的机载版本PVM-100A的LWC响应在两个独立的湿风洞实验中进行了评估，条件控制良好。早期的研究预测PVM-100 （PVM的地面版本）对单分散液滴的理论响应在液滴直径大于约40毫米时减弱。然而，本文的风洞实验结果表明，当液滴直径在20 ~ 30mm之间时，PVM-100A对单分散液滴的响应开始下降。对于多分散的液滴种群（如自然云中发现的液滴），当液滴尺寸分布的中位体积直径（MVD）大于20 mm时，机载PVM-100A的LWC检测效率开始下降，当MVD为50 mm时，效率下降到50%。因此，PVM-100A在液滴大小分布较宽（MVD值较大）的自然云中获得的LWC测量值应谨慎对待。
The Gerber Scientific, Inc. Particle Volume Monitor (PVM) is widely used to measure the liquid water content (LWC) and droplet effective radius (reff) of water clouds. The LWC response of the airborne version of this instrument, the PVM-100A, was evaluated in two independent wet wind tunnel experiments under well-controlled conditions. Earlier studies predict that the PVM-100 (the ground-based version of the PVM) theoretical response to monodisperse droplets diminishes for droplet diameters larger than about 40 mm. However, results from the wind tunnel experiments presented in this paper show that the response of the PVM-100A to monodisperse droplets begins to decrease when the droplet diameter is between 20- and 30-mm diameter. For polydisperse droplet populations (such as those found in natural clouds) the efficiency of the airborne PVM-100A for sensing LWC begins to decrease when the median volume diameter (MVD) of the droplet size distribution is above 20 mm, falling to 50% efficiency for an MVD of 50 mm. Therefore, measurements of LWC obtained from the PVM-100A in natural clouds with broad droplet size distributions (and large values of MVD) should be treated with caution.