Irrigation or Filtration Pump
This application of Pliant Energy's core technology may have its greatest impact in developing regions of the world. Pliant Energy's TWH Pump and earlier Ribbon Pump harness the energy of any flowing water source to pump water out of that source. No electricity or fuel required so long as the water is flowing along a river, a channel or even a shallow stream. The non-rotating action and streamlined profile of the pump makes is highly resistant to debris or heavy object impact. The soft undulating fins are harmless to people in and around the water performing daily activities like swimming, washing clothes, bathing or fishing. Potential applications include crop irrigation and pushing water at pressure through a filtration system for clean drinking water.
Right: TWH Pump tethered to a stake in a stream.
Below: Animation of TWH Pump in operation.
Below: Ribbon Pump concept animation.
The majority of Pliant Energy's R&D has been conducted in-house. While working on the Ribbon Pump however we have had some engagement with academia. We tested pre-prototype devices at Cornell University's DeFrees Hydraulics Lab and caught the attention of Lab Director Edwin A. Cowen. Pliant Energy donated a device for Cornell to study which led to the publication of the paper “Development of a novel, robust, sustainable and low cost self-powered water pump for use in free-flowing liquid streams", Renewable Energy 91:466-476, with faculty and students of Cornell University and members of Pliant Energy Systems listed as co-authors. One of the students, Diego F. Muriel, continues study of the ribbon mechanism's underlying operating principles through his PhD thesis. Along with Prof. Cowen he continues to present at conferences and recently published a paper on the ribbon mechanism titled “Flapping Instability Induced in an Externally Deformed Flexible Plate,” Journal of Fluid Mechanics, Feb 2017.
Numerical modeling of the ribbon mechanism's fluid dynamics has been carried out in collaboration with Prof. Assad Oberai and Dr. Ehsan Shams of RPI's Scientific Computation Research Center. The work was presented at the 68th Annual Meeting of the APS Division of Fluid Dynamics, with Benjamin Pietro Filardo, Baoxiang Shan and Daniel S. Zimmerman of Pliant Energy listed as co-authors.
The video below is from a lab test at the DeFrees Hydraulics of a simple Pliant Energy Systems mechanism undulating in the flow of a flume tank. The light is from a laser for PIV tracking.
The video below shows an early in-house simulation of the Ribbon Pump mechanism using Abaqus FEA modeling software (left) and a prototype tank test (right).