Book Description

The water tunnel described produces sinusoidal flow with peak velocities adjustable from 0 to at least 30 centimeters per second for any period between 3 and 25 seconds. The tunnel is of U-tube design with the middle horizontal part comprising the test section. The vertical end parts are two cylinders with tight-fitting pistons at one end, and two reservoirs open to air at the other. The pistons are driven by a variable-speed electric motor, with an adjustable counterweight permitting operation at resonance at any period. (Author).