...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Flow Measurement and Instrumentation >Numerical-based theoretical analysis on effects of weak fluid acceleration of free-stream due to wind-tunnel blockage on grid-generated turbulence
【24h】

Numerical-based theoretical analysis on effects of weak fluid acceleration of free-stream due to wind-tunnel blockage on grid-generated turbulence

机译：基于数值的理论分析，对自由流弱流体加速度造成的弱流堵塞对网格产生湍流的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We present a numerical-based theoretical analysis for effects of weak fluid acceleration of free-stream due to wind-tunnel blockage on grid-generated turbulence. The increasing of displacement thickness in the developing of the boundary layers due to wind-tunnel blockage reduces the effective area of the test section of the wind tunnel. Wind tunnel blockage, which often occurs in small wind tunnels, could accelerate the freestream in the wind tunnel and thereby affect the decay of grid-generated turbulence. A previous study proposed a mathematical form that validated the blockage effects on the grid-generated turbulence by demonstrating that the fluid acceleration is too weak to affect the anisotropy of the grid-generated turbulence. The previous study used the governing equation of the two-equation model based on thek??modeling. The present study have derived a mathematical form to describe the effects of weak fluid acceleration by using the governing equation used in the previous study with simple numerical simulation. The previous mathematical form has an applicable limit ofSt<0.2. Here,Sis the streamwise nondimensional acceleration rate and is defined asS=(dU′/dx′)/(Uo/M), whereU′,x′,Uo, andMare the streamwise mean velocity, the streamwise direction, the inflow velocity, and the mesh size, respectively. Moreover,tis the convection time normalized by the characteristic timeM/Uo, which may be comparable to the normalized streamwise directionx/Mfor smallS. The applicable limit in the present mathematical form is increased thirty-fold compared with that of the previous mathematical form. The effectiveness of the present scheme is then discussed using a scheme derived from the one-equation model as well as the previous scheme.
机译：我们提出了一种基于数值的理论分析，用于自由流的弱流体加速度对网格产生的湍流堵塞的影响的理论分析。由于风隧道堵塞引起的边界层显影中的位移厚度的增加减少了风洞的试验部分的有效面积。风洞堵塞，通常发生在小风隧道中，可以加速风洞的自由流，从而影响电网产生的湍流的衰减。先前的研究提出了一种数学形式，通过证明流体加速度太弱而无法影响电网产生的湍流的各向异性，验证了对网格产生的湍流的堵塞效应。先前的研究基于TheK的建模使用了两方程模型的控制方程。本研究衍生了一种数学形式，以描述通过使用先前研究中使用的控制方程与简单数值模拟的控制方程来描述弱流体加速的影响。以前的数学形式的适用限制<0.2。这里，SIS是流动的非潜能加速率，并且是定义的ass =（du'/ dx'）/（uo / m），其中x'，uo，并且是流动平均速度，流动方向，流入速度和网格尺寸分别。此外，TIS由特征inem / UO归一化的对流时间，其可以与归一化流动方向的归一化流向Idiftx / Mfor小。与先前的数学形式相比，本数学形式中的适用限制增加了三十倍。然后使用从单方程模型以及先前方案衍生的方案讨论本方案的有效性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号