Dynamic Capillary Fringe: Flow and Transport Processes

动态毛细条纹(CF)在从连续相到不连续相再到缺失气相的转变过程中产生了许多基本问题。这显然影响了气相中的传输，但也影响了与空气流动强烈耦合的水的形成。在这个子项目中，我们想要(I)研究瞬变强迫下CF的动力学，并评估其可用有效的连续体属性表示的程度；(Ii)确定在瞬变强迫下残留气相的形成和溶解；以及(Iii)研究包气带、CF和地下水的水相中的弥散现象，特别是探索这三个区域的有效公式。这些实验将在Hele-Shaw小室中进行，并通过光传输、近红外成像光谱和小型张力计阵列进行观察。完整的三维研究将在SP Z的中央实验设施中进行。在第二阶段，将研究颗粒物的传输以及生物膜对流动和传输的影响。

A dynamic capillary fringe (CF) poses a number of fundamental problems that originate in the transition from a continuous to a discontinuous and finally to a missing air phase. This apparently affects transport in the gas phase but also the very formulation of water flow which becomes strongly coupled with the air flow. In this sub-project, we want to (i) investigate the dynamics of the CF under transient forcing and assess the extent to which it may be represented by effective continuum properties, (ii) determine the formation and dissolution of a residual gas phase under transient forcing, and (iii) study dispersion phenomena in the water phase of the vadose zone, of the CF, and of the groundwater and in particular explore effective formulations for the three zones. The experiments will be run in Hele-Shaw cells and observed through light transmission, near-infrared imaging spectroscopy, and small tensiometer arrays. Full three-dimensional studies will be conducted in the central experimental facility of SP Z. In the second phase, transport of particulate matter will be studied as well as the impact of biofilms on flow and transport.