A simple experimental method is investigated to evaluate the drag force acting on a building structure by controlling the Froude number in an open channel flow hydraulic test. A weir model is installed upstream of the building model, and the overflowing flow interacts with the building structure. This experimental method, which generates a critical flow by overflowing a weir model, is commonly used in civil engineering. By adjusting the overflow rate, the Froude number of the flow reaching the downstream building structure can be varied, enabling the evaluation of the corresponding drag force.
