• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Mathematical Problems in Engineering >Analysis of Flow Evolution and Thermal Instabilities in the Near-Nozzle Region of a Free Plane Laminar Jet
【24h】

Analysis of Flow Evolution and Thermal Instabilities in the Near-Nozzle Region of a Free Plane Laminar Jet

机译：自由平面层流射流近喷嘴区的流动演化和热不稳定性分析

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

This work focuses on the evolution of a free plane laminar jet in the near-nozzle region. The jet is buoyant because it is driven by a continuous addition of both buoyancy and momentum at the source. Buoyancy is given by a temperature difference between the jet and the environment. To study the jet evolution, numerical simulations were performed for two Richardson numbers: the one corresponding to a temperature difference slightly near the validity of the Boussinesq approximation and the other one corresponding to a higher temperature difference. For this purpose, a time dependent numerical model is used to solve the fully dimensional Navier-Stokes equations. Density variations are given by the ideal gas law and flow properties as dynamic viscosity and thermal conductivity are considered nonconstant. Particular attention was paid to the implementation of the boundary conditions to ensure jet stability and flow rates control. The numerical simulations were also reproduced by using the Boussinesq approximation to find out more about its pertinence for this kind of flows. Finally, a stability diagram is also obtained to identify the onset of the unsteady state in the near-nozzle region by varying control parameters of momentum and buoyancy. It is found that, at the onset of the unsteady state, momentum effects decrease almost linearly when buoyancy effects increase.
机译：这项工作的重点是在近喷嘴区域自由平面层流的演变。射流是有浮力的，因为它是由源头上浮力和动量的不断增加所驱动的。浮力由射流和环境之间的温差决定。为了研究射流的演变，对两个理查森数进行了数值模拟：一个对应于一个稍微接近Boussinesq逼近有效性的温度差，另一个对应于一个更高的温度差。为此，使用时间相关的数值模型来求解全维Navier-Stokes方程。密度变化是由理想气体定律给出的，并且由于动态粘度和导热系数被认为是非恒定的，因此具有流动特性。特别注意边界条件的执行，以确保射流稳定性和流量控制。还通过使用Boussinesq逼近来重现数值模拟，以进一步了解其与此类流的相关性。最后，通过改变动量和浮力的控制参数，还获得了一个稳定性图，以识别近喷嘴区域中的非稳态状态。发现在不稳定状态开始时，当浮力作用增加时，动量作用几乎线性减小。

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