**2.2. Model validation for tsunami generation due to a falling fluid**

#### *2.2.1. Experimental setup*

In order to validate the applicability of the numerical model, several numerical results for water surface displacements, are compared with the corresponding experimental data. **Figure 4** depicts a setup for laboratory experiments, with an acrylic basin, where *h*off denotes the still water depth off of the slope, i.e., the offshore still water depth, and the water density is 1000 kg/m3 . The vertical steel gate, installed on a slope with a constant gradient of *β*, can be pulled up quickly, and smoothly, by operating two levers as shown in **Figure 5**, resulting in the release of objects, stacked on the onshore side of the gate. When the gate is closed, its bottom edge touches the shoreline in the still water condition. The height of the falling‐body front face along the vertical gate, is denoted by *h*s. In the experiments for model validation, the falling body is water, with the same density as that of the offshore water, i.e., 1000 kg/m3 .

**Figure 4.** The hydraulic basin with a slope on which a gate is installed. The basin width is 2.0 m.

**Figure 5.** The gate, with two levers, set on the slope in the hydraulic basin as shown in **Figure 4**.
