• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>ASME(American Society of Mechanical Engineers) Pressure Vessels and Piping Conference 2006 vol.4 pt.B: Fluid-Structure Interaction >MICROSCALE FLUID FLOW AT ROUGH METALLIC SURFACES: A LATTICE BOLTZMANN STUDY
【24h】

MICROSCALE FLUID FLOW AT ROUGH METALLIC SURFACES: A LATTICE BOLTZMANN STUDY

机译：粗糙金属表面上的微尺度流体流动：格子Boltzmann研究

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

In contradiction with common assumptions of a laminar lubricant flow, it is shown that high Reynolds number lubricant flows may occur in usual metal forming processes even at scales as small as the surface roughness asperities. This enhances the sensitivity of the flow to perturbations arising e.g. from the surface roughness and brings about the possibility of a roughness-induced transition toward an unsteady flow/turbulence. Via lattice Boltzmann simulations, it is shown that, under these circumstances, a qualitative change in flow properties may indeed be triggered by a variation of the wall roughness alone. We focus on the impact of various roughness parameters on the transition showing that it is not the roughness height alone which determines the onset of flow instability. Rather, it is the combined effect of the roughness height- and wave length which is essential. In particular, by an increase of the roughness wave length, it is possible to trigger flow instability even if the roughness slope is reduced. These findings are in line with experimental results on rough wall turbulence which indicate that a local Reynolds number based on the roughness height alone does not capture the roughness effects on the flow characteristics.
机译：与层流润滑剂流动的一般假设相反，已表明，即使在与表面粗糙度粗糙程度相同的尺度下，在通常的金属成形工艺中也可能发生高雷诺数的润滑剂流动。这提高了流动对例如产生的扰动的敏感性。这是由于表面粗糙度引起的，并可能导致由粗糙度引起的向不稳定的流动/湍流过渡。通过晶格玻尔兹曼模拟，表明在这种情况下，流动性能的质变确实可能仅由壁粗糙度的变化触发。我们集中于各种粗糙度参数对过渡的影响，表明不是由粗糙度高度决定流动不稳定的开始。相反，至关重要的是粗糙度高度和波长的综合作用。特别地，通过增加粗糙度波长，即使减小了粗糙度斜率，也可能触发流动不稳定性。这些发现与粗糙壁湍流的实验结果一致，后者表明仅基于粗糙度高度的局部雷诺数不能捕获粗糙度对流动特性的影响。

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