...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Experimental Thermal and Fluid Science: International Journal of Experimental Heat Transfer, Thermodynamics, and Fluid Mechanics >On the accuracy of void fraction measurements by single-beam gamma-densitometry for gas-liquid two-phase flows in pipes
【24h】

On the accuracy of void fraction measurements by single-beam gamma-densitometry for gas-liquid two-phase flows in pipes

机译：用单束伽马密度法测量管道中气液两相流中空隙率的准确性

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

Gamma-densitometry is a widespread method of measuring non-intrusively the local void fraction of gas-liquid two-phase pipe flows. Using standard single-beam gamma-densitometry, an accurate correlation between the loss of radiation intensity in a test volume and its void fraction provides knowledge of the prevailing flow regime. These regimes are mathematically difficult to describe, due to their complex structure. Therefore the flow regime dependence is usually ignored and the loss of intensity is related to the void fraction by universal linear or logarithmic approximations. This work refers to the accuracy of these approximations, as the achievable accuracy of single-beam gamma-densitometry is highly important in practical applications. The deviations of both approximations are calculated numerically for modeled flow patterns. A dimensionless relation is deduced, which gives their accuracy as a function of the pipe radius and the absorption coefficient of the liquid phase. Experiments with water-air flows in a 21 mm diameter pipe and an Iodine-125 gamma-source confirm the numerical calculations. A method is outlined to deduce the achievable accuracy in practical use directly from the mass flows, the radiation energy and the pipe radius. (C) 2003 Elsevier Inc. All rights reserved.
机译：伽玛密度法是一种非侵入式的非侵入式测量气液两相管道流局部空隙率的方法。使用标准的单束伽马密度计，可以准确了解测试体积中辐射强度的损失与其空隙率之间的相关性，从而了解当前的流态。由于其复杂的结构，这些机制在数学上难以描述。因此，通流线性关系通常被忽略，并且强度损失通过通用线性或对数近似与空隙率相关。这项工作涉及这些近似值的精度，因为单束伽马密度计的可达到精度在实际应用中非常重要。对于模型化的流态，数值计算出两个近似值的偏差。推导出无量纲的关系，该关系给出了其精确度与管道半径和液相吸收系数的函数关系。在直径为21 mm的管道和Iodine-125伽马射线源中进行水-空气流动的实验证实了数值计算。概述了一种方法，可直接根据质量流量，辐射能和管道半径推断出实际使用中可达到的精度。 （C）2003 Elsevier Inc.保留所有权利。

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