Bicycle Powered Centrifugal Irrigation Pump, Power Sweep Constant Head Experiment

In addition to the efficiency at normal use, I wanted to know if the pump used in the first prototype was the most efficient size for human power, as there have not been centrifugal pumps designed specifically for human powered use. At a constant vertical head of 4 meters, I varied the input power to sweep through the pump’s efficiencies. Procedure: Constant Head, Varied Power To control the input power in this experiment, the pedaler again watched a live readout of cadence which is a reasonable proxy for power. At 4 meters (13 feet) of vertical head, I took multiple trials at cadences ranging from 70 to 105 rpms. Once they reach a stable cadence, the pedaler would simultaneously start a timer and call out to the outlet person to switch the outlet flow from filling an auxiliary bucket to filling the measurement bucket. The outlet person would later call out when the measurement bucket was filled to 20 liters, and the pedaler would stop the timer.