• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Refractive index matching technique for applications to the study of wakes in stratified fluids.
【24h】

Refractive index matching technique for applications to the study of wakes in stratified fluids.

机译：折射率匹配技术，用于研究分层流体中的尾流。

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

Due to their prevalence in both nature and practical engineering applications, the mechanics of wakes in stratified fluids is of particular interest. The strong influence of buoyancy forces causes unique wake structures to emerge that are not present in non-stratified wakes. The flow properties and wake structures are well documented at intermediate and late times, but little information is known at early times when properties characteristic of stratified wakes first begin to appear. Optical measurement techniques, such as Particle Image Velocimetry (PIV), have been successful thus far, but do not perform well at early times when the flow is turbulent and large density variations are prevalent. This paper investigates whether a refractive index matching (RIM) technique can be used to make accurate optical measurements in early wakes.;A procedure for creating a RIM linear stratification using 100% ethanol and salt (NaCl) solutions is presented. The success of the procedure is verified by measuring perceived disturbances caused by RI differences through the wake of a towed mesh in three fluid environments: a RIM stratified fluid, a non-RIM stratified fluid, and pure water. For both stratified cases, N ≈ 0.86, Fr ≈ 10.5, and Re ≈ 22 x10 3. By comparing the three environments, the RIM procedure was found to improve resolution by reducing horizontal and vertical velocity RMS values by ≥80% and ≥75%, respectively. Furthermore, RIM perceived disturbances were reduced to levels characteristic of the single RI, pure water environment.
机译：由于它们在自然界和实际工程应用中的普遍性，因此特别关注分层流体中的尾流力学。浮力的强大影响导致出现独特的尾流结构，这种结构在非分层尾流中不存在。流动特性和尾流结构在中晚期都得到了很好的记录，但是在分层尾流的特性首次开始出现时，早期就知之甚少。迄今为止，光学测量技术（例如“粒子图像测速”（PIV））已获得成功，但在流动湍流且普遍存在较大密度变化的早期阶段表现不佳。本文研究了折射率匹配（RIM）技术是否可用于在早期苏醒中进行准确的光学测量。;提出了使用100％乙醇和盐（NaCl）溶液创建RIM线性分层的程序。通过测量三种流体环境（RIM分层的流体，非RIM分层的流体和纯净水）中拖曳的网格引起的RI差异引起的感知干扰，验证了该过程的成功。对于这两个分层的案例，N＆ap; 0.86，Fr＆ap; 10.5，然后Re＆ap; 22 x 10 3.通过比较三种环境，发现RIM程序通过分别将水平和垂直速度RMS值分别降低≥80％和≥75％来提高分辨率。此外，RIM感知的干扰已降低到单个RI纯水环境的特征水平。

著录项

  • 作者

    Wimer, Anthony.;

  • 作者单位

    University of Southern California.;

  • 授予单位 University of Southern California.;
  • 学科 Engineering Mechanical.
  • 学位 M.S.
  • 年度 2011
  • 页码 71 p.
  • 总页数 71
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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