Poncelet wheel

Traditional undershot waterwheels consisted of a series of flat blades fixed to the rim of a wheel.

Instead, undershot water wheels are used in low head sites, like less than 1.5 m, and they also exploit the potential energy of the flow, with efficiencies of up to 84%.

Jean Charles de Borda was the first to directly characterize the efficiency of waterwheels by comparing the velocities of water before and after meeting the wheel.

[3] Several commercial models followed, including a large installation in Metz that delivered 33% more power than the traditional wheel it replaced, in spite of implementing only some of the design .

However, the large-scale installation of steam engines and water turbines led to the Poncelet wheel falling from use.