SURFACE TENSION DRIVEN WATER PUMPING by J Fraser
SURFACE TENSION DRIVEN WATER PUMPING by J. Fraser & R. T. Dobson University of Stellenbosch Energy Postgraduate Conference 2013
Overview i. Themba LABS • Introduction • Background and Objectives • Main Theory • Problems • Why it works Falling water droplet • Conclusion SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
Introduction i. Themba LABS • Nature Examples: has adapted of millions of years • • – Elephant trunk – Gecko feet Humans can learn much from nature – Shark skin – Lotus leaves – Beehive structure Biomimicry = nature inspired design – Insect Nano robots – And many more SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
Introduction (cont. ) i. Themba LABS • Plant Surface similar elastic membrane on fluid surface lifetension: thrived on Earthtofor thousands of years • Nature found myriad of exploitations: • Pump water seemingly effortlessly • – Small insects stride on water – Bacteria releases surfactant for driving force Giant Redwoods grow up control to 100 formpropulsion tall – Some larva employs vector • • Useful for water pumping Recentmechanism applications: • In– a. Small timeobject of water shortages, propulsion – Nano-robots maneuverability climate change, power consumption – Capillary action and emmision concerns – Micro pumping – etc SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
Background & Objectives i. Themba LABS • Plant Leaves: • • – Photosynthesis: water + carbon dioxide + energy carbohydrates +oxygen Ingenious water transport mechanism of plants Capillary-driven heat pipe technology mechanisms Construct mechanical/artificial pump First step in a larger project: – wherein hydrogen, food (carbohydrates) and fuel are artificially produced. • For this project: – build mechanically-constructed experimental simulation working model of transport mechanism – Theoretical thermal-hydraulic simulation model + validation against experimental model. • After validation use of such a water pump in an artificial photosynthesis program to be established. SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
Main Theory Overview i. Themba LABS • Water Transport in trees Transpiration pull • (TACT) – – Transpiration Adhesion Cohesion Tension SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
Problems i. Themba LABS SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
Why it works i. Themba LABS SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
Why it works i. Themba LABS • Secret Strong adhesion forces Strong cohesion forces Evaporation Surface tension forces • Must prevent nucleation sites – Prevent embolisms • Require a continuous channel of water: – Rerouting – Dissolve bubbles SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
In Conclusion i. Themba LABS • Nature offers many lessons and techniques • Surface tension useful mechanism • Tree water pumping mechanism investigation • Theory, build, experiment & validate SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
Acknowledgements i. Themba LABS • Mr. Dobson • Family SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
END i. Themba LABS THANK YOU SAHPA® South African Heat Pipe Association Energy Postgraduate Conference EPC 2013, 11 -14 Aug 2013
- Slides: 12