A cross-flow turbine was tested to determine the magnitude of the fluid forces on the blades. The tangential and radial forces and the torque were measured on a test blade.

Because the runner was made of plexiglas, the flow and the effects of the incidence angle at various speeds were observed.

The pattern of blade loading over a revolution was measured over a range of heads from 1.0 to 2.6 m. The maximum forces were found to occur just before the blade leaves the nozzle exit.

The experimental forces agree reasonably well with the results of a control volume analysis. Two figures are provided, by which the designer may determine the tangential and radial forces for any geometrically similar machine.