Theoretical prediction and design for vortex generators in turbulent boundary layers
Theoretical prediction and design for vortex generators in turbulent boundary layers
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湍流边界层涡发生器的理论预测与设计
DOI：
10.1017/s0022112094004210
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发表时间：
1994
影响因子：
3.7
通讯作者：
F. Smith
中科院分区：
文献类型：
--
作者：
F. Smith
本文从理论上研究了在边界层中由一组低剖面涡发生器（VG）引起的三维湍流流动。典型的VG位于入射边界层的对数区域，并且所使用的湍流模型似乎在该区域具有代表性。控制方程产生一个向前推进的三维涡型系统，这是解决展向周期VG阵列的计算和分析。由于原始对数剖面的三维畸变和湍流应力的存在，下游产生了各种强度的流向涡型。某些基本的VG形状，如三角形，与各种展向间距的预测，并发现同意有利的整体与最近的实验。此外，得到的分析公式证明是有用的，在建议设计有利的VG分布，基于三个因素：紧密的展向填料，增加VG长度，和适当的非光滑展向成形。
A theoretical study is presented of three-dimensional turbulent flow provoked in a boundary layer by an array of low-profile vortex generators (VGs) on the surface. The typical VG sits in the logarithmic region of the incident boundary layer, and the turbulence model used seems representative in this region. The governing equations yield a forward-marching three-dimensional vortex-type system, which is solved computationally and analytically for spanwise periodic VG arrays. Streamwise vortex patterns of various strengths are produced downstream, owing to three-dimensional distortion of the original logarithmic profile and to the turbulent stresses present. Predictions are given for certain basic VG shapes, e.g. triangular, with various spanwise spacings, and the predictions are found to agree favourably overall with recent experiments. In addition, the analytical formulae obtained prove useful in suggesting designs for favourable VG distributions, based on three factors: close spanwise packing, increased VG length, and suitably non-smooth spanwise shaping.