Limits...
Modeling the future of irrigation: A parametric description of pressure compensating drip irrigation emitter performance

View Article: PubMed Central - PubMed

ABSTRACT

Drip irrigation is a means of distributing the exact amount of water a plant needs by dripping water directly onto the root zone. It can produce up to 90% more crops than rain-fed irrigation, and reduce water consumption by 70% compared to conventional flood irrigation. Drip irrigation may enable millions of poor farmers to rise out of poverty by growing more and higher value crops, while not contributing to overconsumption of water. Achieving this impact will require broadening the engineering knowledge required to design new, low-cost, low-power drip irrigation technology, particularly for poor, off-grid communities in developing countries. For more than 50 years, pressure compensating (PC) drip emitters—which can maintain a constant flow rate under variations in pressure, to ensure uniform water distribution on a field—have been designed and optimized empirically. This study presents a parametric model that describes the fluid and solid mechanics that govern the behavior of a common PC emitter architecture, which uses a flexible diaphragm to limit flow. The model was validated by testing nine prototypes with geometric variations, all of which matched predicted performance to within R2 = 0.85. This parametric model will enable irrigation engineers to design new drip emitters with attributes that improve performance and lower cost, which will promote the use of drip irrigation throughout the world.

No MeSH data available.


Iterative process used to model the coupled fluid-structure behavior within a drip emitter.A. Block diagram of the solver. B. The flow rate is solved iteratively for each increment of inlet pressure. The vertical dashed lines correspond to input pressure steps in the model. The circles are iterative solutions to flow rate. The asterisks are the final solution of flow rate for each inlet pressure. This model results in the full pressure versus flow rate relationship for a emitter of given internal geometry and membrane material.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5383273&req=5

pone.0175241.g006: Iterative process used to model the coupled fluid-structure behavior within a drip emitter.A. Block diagram of the solver. B. The flow rate is solved iteratively for each increment of inlet pressure. The vertical dashed lines correspond to input pressure steps in the model. The circles are iterative solutions to flow rate. The asterisks are the final solution of flow rate for each inlet pressure. This model results in the full pressure versus flow rate relationship for a emitter of given internal geometry and membrane material.

Mentions: Fig 6 graphically depicts the iterative process used to solve the coupled fluid-structure system in this study. The output of the iteration is an inlet pressure versus flow rate curve that depends on the fluid flow path geometry and membrane materials within the emitter. For every increment of the inlet pressure (vertical dashed lines in Fig 6), the model iteratively calculates the flow rate out of the emitter (asterisks in Fig 6).


Modeling the future of irrigation: A parametric description of pressure compensating drip irrigation emitter performance
Iterative process used to model the coupled fluid-structure behavior within a drip emitter.A. Block diagram of the solver. B. The flow rate is solved iteratively for each increment of inlet pressure. The vertical dashed lines correspond to input pressure steps in the model. The circles are iterative solutions to flow rate. The asterisks are the final solution of flow rate for each inlet pressure. This model results in the full pressure versus flow rate relationship for a emitter of given internal geometry and membrane material.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5383273&req=5

pone.0175241.g006: Iterative process used to model the coupled fluid-structure behavior within a drip emitter.A. Block diagram of the solver. B. The flow rate is solved iteratively for each increment of inlet pressure. The vertical dashed lines correspond to input pressure steps in the model. The circles are iterative solutions to flow rate. The asterisks are the final solution of flow rate for each inlet pressure. This model results in the full pressure versus flow rate relationship for a emitter of given internal geometry and membrane material.
Mentions: Fig 6 graphically depicts the iterative process used to solve the coupled fluid-structure system in this study. The output of the iteration is an inlet pressure versus flow rate curve that depends on the fluid flow path geometry and membrane materials within the emitter. For every increment of the inlet pressure (vertical dashed lines in Fig 6), the model iteratively calculates the flow rate out of the emitter (asterisks in Fig 6).

View Article: PubMed Central - PubMed

ABSTRACT

Drip irrigation is a means of distributing the exact amount of water a plant needs by dripping water directly onto the root zone. It can produce up to 90% more crops than rain-fed irrigation, and reduce water consumption by 70% compared to conventional flood irrigation. Drip irrigation may enable millions of poor farmers to rise out of poverty by growing more and higher value crops, while not contributing to overconsumption of water. Achieving this impact will require broadening the engineering knowledge required to design new, low-cost, low-power drip irrigation technology, particularly for poor, off-grid communities in developing countries. For more than 50 years, pressure compensating (PC) drip emitters—which can maintain a constant flow rate under variations in pressure, to ensure uniform water distribution on a field—have been designed and optimized empirically. This study presents a parametric model that describes the fluid and solid mechanics that govern the behavior of a common PC emitter architecture, which uses a flexible diaphragm to limit flow. The model was validated by testing nine prototypes with geometric variations, all of which matched predicted performance to within R2 = 0.85. This parametric model will enable irrigation engineers to design new drip emitters with attributes that improve performance and lower cost, which will promote the use of drip irrigation throughout the world.

No MeSH data available.