Hello!
I want to calculate the flow rate in a DFN model. I used the function flowplane.zone.discharge to obtain the flow vectors within a loop foreach over flowplane.zone.list, with block fluid crack-flow on enabled. Then, I applied math.mag to compute the discharge magnitude in m²/s. Finally, I multiplied this value by the fracture aperture to calculate the flow rate in m³/s. Is this approach correct?
You need to multiply the discharge by the width of the zone (perpendicular to the vector) to get a volumetric flow rate. The safest way to determine the volumetric flow rate is to sum the knot unbalanced volumes along an edge (or joint boundary).
Thank you for the response. How does the joint aperture influence the calculation of unbalanced volumes at knots? I did not define this property explicitly in my FISH function, I simply summed all knot unbalanced volumes along the joint boundary.
Yes, the aperture is accounted for in the knot volume. Have a look at this example to calculate inflow and outflow
flow_only.dat (1.3 KB)