...
首页> 外文期刊>Soil Science Society of America Journal >Application of the Fractional Advection-Dispersion Equation in Porous Media
【24h】

Application of the Fractional Advection-Dispersion Equation in Porous Media

机译:分数维对流弥散方程在多孔介质中的应用

获取原文
获取原文并翻译 | 示例
           

摘要

According to the classical advection-dispersion equation (ADE), the variance of travel distance increases linearly with the time elapsed after the release of a solute tracer. However, several field studies showed nonlinear relationships exist between the variance of travel distance for solute tracers and time. Therefore, the transport at the field scale often shows non-Gaussion property. To describe the non-Gaussian transport process, a fractional advection-dispersion equation (FADE) is a possibility. Fractional ADE has been applied to the transport process of non-reactive solutes in a laboratory sandbox as well as that for the Cape Cod field site. In this paper, we discuss several issues regarding the application of FADE. Because of the complexity of the FADE, its application often needs justification. We propose an F-test to judge whether a FADE is necessary. For the Cape Cod experiment, the FADE of order 1.82 is necessary according to our F-test results. In addition, we present a method to estimate the dispersion coefficient and fractional order simultaneously. The obtained parameters from joint estimation will recover the variance-time relationship. Finally, we pointed out that the dispersivity-time or dispersivity-mean travel distance relationship is needed to estimate the fractional order . Use of dispersivity-distance relationship for estimating the fractional order is theoretically unjustified and may result in unreasonable values.
机译:根据经典对流扩散方程(ADE), 的行进距离方差随溶质示踪剂释放后的 时间线性增加。但是, 多次野外研究表明, 溶质示踪剂的行进距离方差与时间之间存在非线性关系。 因此,田间尺度的运移通常显示非Gaussion 属性。为了描述非高斯输运过程,有可能使用 对流对流弥散方程(FADE)。 分数阶ADE已用于 < / sup>实验室沙箱中的非反应性溶质以及鳕鱼角油田现场的 。在本文中,我们讨论了有关FADE应用的几个 问题。由于FADE的复杂性 ,其应用常常需要证明。我们提出 F检验来判断是否需要进行FADE。对于Cape Cod实验,根据我们的F检验结果,必须按 的阶数为1.82的FADE。此外,我们提出了一种同时估计 色散系数和分数阶的方法。 从联合估计中获得的参数将恢复 方差时间关系。最后,我们指出需要 色散时间或色散平均行程距离关系 来估计分数阶。在理论上,使用色散-距离 关系来估计分数阶是 不合理的,可能会导致值不合理。

著录项

  • 来源
    《Soil Science Society of America Journal》 |2003年第4期|1079-1084|共6页
  • 作者

    Liuzong Zhou; H. M. Selim;

  • 作者单位

    Agronomy Dep., Sturgis Hall, Louisiana State Univ., Baton Rouge, LA 70803;

    Agronomy Dep., Sturgis Hall, Louisiana State Univ., Baton Rouge, LA 70803;

  • 收录信息
  • 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