Carlos Andres Rivera Villarreyes Global Product Specialist - FEFLOW

Hi Emilia, Refinement is not necessary the solution. You should look for the Mesh Quality. How good is the mesh if you plot the Max. Interior Angle of triangles? For example, if you do the refinement in bad-shaped triangles, then the situation will become even worst. Why are you using the Error Norm (max.)? Is your problem converging?  Get in touch with MIKE Support (mike.de@dhigroup.com) and discuss your case in detail. Best regards Carlos Rivera

Hi Rachit, To understand better the case, can you elaborate how you are launching the 1000's simulations? Is this done under the FePEST framework? Or are you using your own script to do the job? The issue with the MPI can be related to several things, for example, you already have an MPI environment in place, which could conflict with FEFLOW's one. Or the script is not properly terminating the MPI instance. Best regards Carlos Rivera

Hi Lucien, If you are solving the groundwater flow equation with the option "Free" surface, then FEFLOW assumes that the elevation of Slice 1 coincides with the phreatic surface (Pressure = 0 kPa). Therefore, the model elevation will change accordingly during the simulation. You can solve the groundwater flow equation by using the "Phreatic" option or the Problem Class Richards. We have dedicated free training course about all these options. You can register with the link below: https://www.theacademybydhi.com/course-sessions/feflow---behind-the-flow-11600061-142 Best regards Carlos Rivera  

No, it is not possible. Hydrodynamics model for rivers cannot be solved with steady-state concept. If you prefer to work in steady, then you would need to operate only with FEFLOW, where the river heads are prescribed by the Fluid-Transfer BC. Best regards, Carlos

Hi Max, The problem is that SAMG did not converge properly. I see you are working with a RMS norm. This is practical for standard cases, but in situations, where you have specific "hot spots" (e.g. not convergence directly at the BHE locations), it will be much useful to work with a MAX norm. The Max norm will focus on the spots with maximum error, presumably the BHE locations. Alternatively, you can give a try with the direct solver PARDISO. Best regards Carlos Rivera

Hi Tomás, I recommend you to get in touch with MIKE support (mike.de@dhigroup.com). The question is very generic and the fact of increasing the number of layers does not clarify the changes of water balances. Indeed, the Multilayer Well is an imposed source/sink. You would need to see this in the Rate Budget panel.  Best regards Carlos

Hi Sebastian, interesting question. You can change the direction of the gravity vector, but not the magnitude. I am wondering whether you could do a math trick by upscaling/downscaling other parameters in order to achieve your purposes. Cheers Carlos

Hi Adam, Density-driven flow problems are hard to solve, but not impossible. Negative concentrations are due to the poor discretization level and dispersivity values assigned to the model. If I were you, I would do the model in steps. Does your model run with constant head values (not tidal effects)? If no, this should be fixed first. You can take a look on the self-paced course below. There is a section covering some information about numerical oscillations and their connections with the mesh size and dispersivity. https://www.theacademybydhi.com/course-sessions/feflow---getting-started-with-groundwater-quality-modelling-11600061-153 Best regards Carlos Rivera

Hi Abel, The method is called getHistoryValues and you can find the documentation below: https://dhi.github.io/ifm/api_doc.html?highlight=history#ifm.FeflowDoc.getHistoryValues Best regards Carlos Rivera

Why don't you use directly the Monte Carlo functionality within FePEST application? You can parallelize with a couple of clicks only.. Cheers Carlos