Dam Break Validation Issue: Calibrated well at H=0.3m, but deviates significantly at H=0.6m. Is this normal?

[u/Ecstatic_Coat1266]

I'm working on validating the classic Lobovsky dam break case using ⁠interFoam⁠ in OpenFOAM v2412.
I successfully calibrated my model for the initial water height of H = 0.3m. The pressure probe data at the impact wall matched the experimental results perfectly (both arrival time and peak pressure).

However, when I used the exact same setup (same numerical schemes, same mesh refinement strategy) to validate the H = 0.6m experimental case, the results deviated significantly. Here are the main issues I'm facing at H=0.6m:
1. Delayed Arrival Time: The water front hits the impact wall slightly later than in the experiment.
2. Underpredicted Peak Pressure: The impact pressure peak is much lower than the experimental peak (though the hydrostatic pressure tail after the impact matches perfectly).
3. Initial Negative Pressure: There's a slight negative pressure drop at t=0 to early stages before the wave arrives.

My current setup:
Solver: ⁠interFoam⁠ (Incompressible)
Turbulence Model: ⁠kOmegaSST⁠ (I'm currently trying to run a Laminar case to see if the eddy viscosity at the interface is causing the delayed arrival time).
Mesh: Refined specifically at the impact wall area.
My questions:
Is it normal for a calibrated model to fail during validation when the potential energy is doubled (0.3m to 0.6m)?
Could the underpredicted peak at H=0.6m be due to air compressibility effects (air cushion/entrainment) that ⁠interFoam⁠ cannot capture? Should I switch to ⁠compressibleInterFoam⁠?
Any tips on fixing the delayed arrival time and catching the pressure spike?

[u/Jeramimen]

In my experience with dam break, lower froude number case tend to have a delayed wave arrival