The recorded DP–V data for an experiment at constant flux can
thus be used to determine aðVÞ, the result for the relative Darcy
parameter aðVÞ=að0Þ is shown in Fig. 3b.
As the measurements contain outliers, we apply a smoothing
method where we require consecutive measurements to deviate
by at most ten percent. This smoothing is depicted by the line in
Fig. 3b; the experimental results are depicted by dots. As the measurements
were stopped once the threshold differential pressure of
1 bar was surpassed, we extended the function by assuming an
exponential decay law. We can use the resulting a–V relationship
as a function in numerical methods by linearly interpolating
between consecutive measurements.