...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Aerospace science and technology >Numerical prediction of nozzle flow separation: Issue of turbulence modeling
【24h】

Numerical prediction of nozzle flow separation: Issue of turbulence modeling

机译：喷嘴流分离的数值预测：湍流建模问题

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

Numerical simulation of separated flows in rocket nozzles is challenging because existing turbulence models are unable to predict it correctly. This paper addresses this issue with the Spalart-Allmaras and Shear Stress Transport (SST) eddy-viscosity models, which predict flow separation with moderate success. Their performances have been compared against experimental data for a conical and two contoured subscale nozzles. It is found that they fail to predict the separation location correctly, exhibiting sensitivity to the nozzle pressure ratio (NPR) and nozzle type. A careful assessment indicated how the model had to be tuned for better, consistent prediction. It is learnt that SST model's failure is caused by limiting of the shear stress inside boundary layer according to Bradshaw's assumption, and by over prediction of jet spreading rate. Accordingly, SST's coefficients were empirically modified to match the experimental wall pressure data. Results confirm that accurate RANS prediction of separation depends on the correct capture of the jet spreading rate, and that it is feasible over a wide range of NPRs by modified values of the diffusion coefficients in the turbulence model. (C) 2015 Elsevier Masson SAS. All rights reserved.
机译：火箭喷嘴中分离流动的数值模拟具有挑战性，因为现有的湍流模型无法正确预测。本文使用Spalart-Allmaras和切应力传输（SST）涡流-粘度模型解决了这个问题，该模型预测了流量分离并取得了一定的成功。他们的性能已与锥形和两个轮廓分刻度的喷嘴的实验数据进行了比较。发现他们无法正确预测分离位置，对喷嘴压力比（NPR）和喷嘴类型表现出敏感性。仔细的评估表明，必须对模型进行调整以获得更好，一致的预测。据了解，SST模型的失效是由于根据布拉德肖的假设限制了边界层内部的剪切应力，以及对射流扩展速率的过度预测而造成的。因此，根据经验修改了SST的系数以匹配实验壁压力数据。结果证实，准确的RANS分离预测取决于对射流扩展速率的正确捕获，并且通过修改湍流模型中扩散系数的值，在广泛的NPR范围内可行。 （C）2015 Elsevier Masson SAS。版权所有。

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