Tracer turbulence: the Batchelor--Howells--Townsend spectrum revisited
Tracer turbulence: the Batchelor--Howells--Townsend spectrum revisited
复制标题
示踪湍流：重新审视巴彻勒-豪厄尔斯-汤森谱
DOI：
10.1007/s00021-019-0478-6
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发表时间：
2020
影响因子：
1.3
通讯作者：
Wirosoetisno, D.
中科院分区：
文献类型：
--
作者：
Jolly, M. S.;Wirosoetisno, D.
给定速度场du(x,t)，我们考虑由与时间无关的源g(x)控制的被动示踪器的演化。Batchelor、Howells和Townsend （J Fluid Mech, 1959）预测，当示踪光谱在某种意义上较小时，示踪光谱的尺度为。在本文中，我们证明了对于给定能谱的随机合成二维不可压缩速度场su(x,t)，对于大b| k|和小b|，这种标度确实在概率上、渐近上几乎肯定地成立。我们还提出了一个渐近校正因子对BHT标度引起的时间依赖性。
Given a velocity fieldu(x,t), we consider the evolution of a passive tracergoverned bywith time-independent sourceg(x). Whenis small in some sense, Batchelor, Howells and Townsend (J Fluid Mech 5:134, 1959) predicted that the tracer spectrum scales as. In this paper we prove that, for random synthetic two-dimensional incompressible velocity fieldsu(x,t) with given energy spectra, this scaling does indeed hold probabilistically, asymptotically almost surely for large |k| and small. We also propose an asymptotic correction factor to the BHT scaling arising from the time-dependence ofu.