Physically-based model of soil hydraulic properties accounting for variable contact angle and its effect on hysteresis
Physically-based model of soil hydraulic properties accounting for variable contact angle and its effect on hysteresis
复制标题
考虑可变接触角的土壤水力特性的物理模型及其对滞后的影响
DOI：
10.1016/j.advwatres.2013.06.005
复制
发表时间：
2013
影响因子：
4.7
通讯作者：
W. Durner
中科院分区：
文献类型：
--
作者：
Diamantopoulos;W. Durner
描述非饱和区土壤水分运动需要了解土壤的水力特性，即保水性和导水性函数。在文献中可以找到大量的参数化，其中大多数将土壤的复杂孔隙空间表示为一束不同大小的圆柱形毛细管。并提出了水与颗粒表面零接触角的假设。然而，这些假设限制了这些模型的预测能力，导致在预测土壤中的水动力学时经常出现错误。考虑了孔尺度滞后和接触角的影响，提出了角孔中平衡液态的孔尺度分析方法。此外，我们提出了水力导电性函数的推导，再次作为接触角的函数。为了考虑分析中未包括的影响，在电导率函数中添加了一个附加参数。最后，我们通过假设孔隙尺寸的gamma统计分布，将我们的模型从孔隙尺度提升到样本尺度。导出了保水和电导率函数的封闭表达式。利用砂质材料的多级流入/流出（MSI/MSO）实验数据对新模型进行了验证。实验采用乙醇和水作为润湿液。假定乙醇与土壤颗粒形成零接触角。通过保持乙醇MSO实验拟合的参数不变，我们可以根据理论预测乙醇MSI动力学。此外，通过保持乙醇实验的孔径分布参数不变，我们也可以很好地预测MSO实验的水动力学。最后，通过引入接触角的有限值，我们可以预测水MSI实验的吸胀动力学。最重要的是，对乙醇和水的MSI/MSO动力学的预测是通过假设一个独特的孔径分布进行的。
The description of soil water movement in the unsaturated zone requires the knowledge of the soil hydraulic properties, i.e. the water retention and the hydraulic conductivity function. A great amount of parameterizations for this can be found in the literature, the majority of which represent the complex pore space of soils as a bundle of cylindrical capillary tubes of various sizes. The assumption of zero contact angles between water and surface of the grains is also made. However, these assumptions limit the predictive capabilities of these models, leading often to errors in the prediction of water dynamics in soils. We present a pore-scale analysis for equilibrium liquid configuration in angular pores taking pore-scale hysteresis and the effect of contact angle into account. Furthermore, we propose a derivation of the hydraulic conductivity function, again as a function of the contact angle. An additional parameter was added to the conductivity function in order take into account effects which are not included in the analysis. Finally, we upscale our model from the pore to the sample scale by assuming a gamma statistical distribution of the pore sizes. Closed-form expressions are derived for both water retention and conductivity functions. The new model was tested against experimental data from multistep inflow/outflow (MSI/MSO) experiments for a sandy material. They were conducted using ethanol and water as the wetting liquid. Ethanol was assumed to form a zero contact angle with the soil grains. By keeping constant the parameters fitted from the ethanol MSO experiment we could predict the ethanol MSI dynamics based on our theory. Furthermore, by keeping constant the pore size distribution parameters from the ethanol experiments we could also predict very well the water dynamics for the MSO experiment. Lastly, we could predict the imbibition dynamics for the water MSI experiment by introducing a finite value of the contact angle. Most importantly, the predictions for both ethanol and water MSI/MSO dynamics were made by assuming a unique pore-size distribution.
影响因子：
5.4
作者：
Andre Peters;W. Durner
通讯作者：
Andre Peters;W. Durner
影响因子：
5.4
作者：
W. Durner;S. Iden
通讯作者：
W. Durner;S. Iden
弯曲三角形横截面孔隙中的毛细管压力行为：润湿性和孔径分布的影响
DOI：
--
发表时间：
1992
期刊：
影响因子：
--
作者：
H. M. Princen
通讯作者：
H. M. Princen