The prototype weir is to discharge under a head of 1.2 m. A scale model of 1/10 size is proposed and the available flow is 42.5 l/s. Determine the heads necessary and the corresponding discharge of...

The prototype weir is to discharge under a head of 1.2 m. A scale model of 1/10 size is proposed and the available flow is 42.5 l/s. Determine the heads necessary and the corresponding discharge of the prototype weir.

The skin resistance of a ship model is given by 5.22


_m

1.95 N/m². For the prototype the skin resistance is given by 4.95


_p

1.9 N/m². The model of 1/20 scale with wetted area of 4 m²
when towed in fresh water at 1.2 m/s. measured a total resistance of 46.2 N. Determine the total resistance of the ship in sea water at speeds corresponding to that of the model. Density of sea water = 1025 kg/m³.