Modulation of Turbulent Flow by Surrogate Asian Carp Eggs
Modulation of Turbulent Flow by Surrogate Asian Carp Eggs
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DOI：
10.1061/9780784482971.013
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
Yilan Li;S. Bennett;Zhenduo Zhu
中科院分区：
文献类型：
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作者：
Yilan Li;S. Bennett;Zhenduo Zhu
在地球物理流中，悬浮和运输中沉积物的存在可以在改变载液的湍流特性方面发挥重要作用。许多研究都集中在直径相对较小（小于 1 毫米）的石英密度 (2.65 g/cm3) 颗粒对湍流的影响。亚洲鲤鱼是美国广泛传播的入侵水生物种，给河流和湖泊造成了严重的生态问题。与沉积物不同，亚洲鲤鱼卵是半浮力颗粒（最初产卵时约为 1.05 g/cm3，水硬化后约为 1.00 g/cm3），其直径稳定在约 5 毫米。本文研究了作为亚洲鲤鱼卵替代物的颗粒的存在对湍流的影响，作为湍流强度的函数。实验在混合箱中进行，振荡网格放置在底部边界附近，并使用 2D PIV 来量化载液的湍流特性。进行了五对有和没有亚洲鲤鱼卵替代颗粒的配对实验。结果表明，在不同的网格振荡频率（2~6Hz）下，颗粒存在下载液的平均动能略有下降，但流体的湍流动能没有明显变化。这强烈表明悬浮的亚洲鲤鱼卵不会改变载体流体的湍流强度。这些实验结果为亚洲鲤鱼卵的夹带、运输和沉积提供了重要的见解，可以为预测这种入侵物种未来传播的模型提供信息。
In geophysical flows, the presence of sediment in suspension and transport can play an important role in modifying the turbulent properties of the carrier fluid. Much research has focused on the effects of relatively small diameter (less than 1 mm) quartz-density (2.65 g/cm3) particles on turbulent flow. Asian carp is a wide-spread invasive aquatic species in the U.S., causing severe ecological problems in rivers and lakes. Unlike sediment, Asian carp eggs are semi-buoyant particles (~1.05 g/cm3when initially spawned and ~1.00 g/cm3in the post-water-hardening period) whose diameter stabilizes to approximately 5 mm. This paper examines how turbulent flow is affected by the presence of particles serving as surrogates for Asian carp eggs as a function of turbulence intensity. Experiments were conducted in a mixing box with the oscillating grid placed near the bottom boundary, and 2D PIV was used to quantify the turbulent characteristics of the carrier fluid. Five paired experiments with and without Asian carp egg surrogate particles were conducted. Results show that under different grid oscillation frequencies (2 to 6 Hz), the mean kinetic energy of the carrier fluid decreased slightly in the presence of the particles, but the turbulent kinetic energy of the fluid did not change appreciably. This suggests strongly that Asian carp eggs in suspension do not modify turbulence intensity of the carrier fluid. These experimental results provide important insight into the entrainment, transport, and deposition of Asian carp eggs, which can inform models to predict the future spread of this invasive species.