@Lisa
If it helps with OGS v5.
You may already have read this dissertation (Walther, TU Dresden, 2013:
https://tud.qucosa.de/landing-page/?tx_dlf[id]=https%3A%2F%2Ftud.qucosa.de%2Fapi%2Fqucosa%253A28302%2Fmets
which compares OpenGeoSys version 5 with MODFLOW/SEAWAT using a numerical simulation of saltwater intrusion, based on a laboratory experiment.
In particular section 3.3, reproduced below:
"3.3 Transient Saltwater Intrusion for Unconfined Conditions
Problem Description.
This benchmark verifies the capabilities of OpenGeoSys to model transient, variable-density groundwater flow and transport against a laboratory setup and numerical Seawat simulation data (Langevin and Guo, 2006). Goswami and Clement (2007) show a saltwater intrusion experiment after Henry (1960), using a laboratory scale tank. The benchmark is an extension to the steadystate setup documented in [P2]: Walther et al. (2012b).
Methods and Model Setup.
The Goswami-Clement problem features a horizontally intruding and withdrawing saltwater front in an initially present freshwater environment. The conceptual model is depicted in figure 3.5, p. I-21, important model parameters are listed in table 3.4, p. I
Results.
Figure 3.6, p. I-22, depicts the comparison of the transient simulations between the experiment and the numerical models. Both simulation tools, Seawat and OpenGeoSys, resemble the measurements quite well in terms of temporal development, shape of the saltwater wedge, and intrusion length. Nevertheless, they also show deviations from the laboratory measurements. While Seawat overestimates intrusion length at the toe of the saltwater wedge, OpenGeoSys generally yields a better prediction or slightly underestimates intrusion length."
And here, with post by Marc Walther himself: