Horizontal landfill wells are long perforated pipes that collect gas within the solid waste matrix undergoing decomposition. The geometric parameters make it challenging to simulate the flow in this system: the aperture size is extremely small (a few centimetres) compared the length of the pipe (a few hundred metres). The problem is further complicated by the fact that outside of the pipe the flow is through a porous medium, whereas inside it is a continuum flow. A full simulation on a mesh that accurately captures the ingress flow is very slow (hours to days, depends on the computer and input parameters), whilst a quasi-1D simplified flow model is very fast (seconds), but not accurate due to an inherent overlooking of ingress losses. Thus industry professionals expressed high interest in creating an empirical upgraded quasi-1D model based on the full simulations of an extensive useful parameter space. This report provides evidence of the impossibility of such an empirical model.
