Dynamical Analysis And Structural Optimization Of Drip Irrigation Emitter Based On CAD/CFD

The hydraulics performance and the internal flow field of drip irrigation emitter are studied through theoretical analysis, numerical simulation and experimental verification. The research contents and conclusions are as follows:(1) Based on drip irrigation emitter, the macro-scale and micro-scale hydromechanics theory are presented. The relationship between flux and pressure is analyzed. Transition Reynolds number of typical emitter labyrinth channel is less than 500. Multidisciplinary design optimization idea is proposed for drip irrigation emitter design. Drip irrigation emitter will have optimal hydraulic performance when MDO is integrated with virtual prototyping technique to optimize the design parameters of emitter.(2) A novel prediction model based on modified PSO least square support vector machine is proposed. The effects of triangle labyrinth channel parameters on hydraulics performance of emitter can be predicted with the limited test data, thus the variation law of hydraulics performance of drip irrigation emitter following labyrinth channel parameters can be obtained.(3) Liquid-solid two-phase theory model was been constructed firstly. The flow characteristic of liquid-solid two-phase in drip irrigation emitter is studied. The influences of liquid pressure drop, concentration distribution and velocity in drip irrigation emitter to liquid-solid two-phase flow characteristic are investigated.(4) Trapezium labyrinth emitter channel has five key parameters, the influence of these five key parameters to hydraulic performance of drip irrigation emitter are carried out by using the Box-Benhnken response surface methodology. Being combined the Multidisciplinary design optimization software OPTIMUS with the computational fluid dynamics software FLUENT to optimize the design of emitter, in the meantime, hydraulic performance has been completely improved after optimization.(5) The three-dimension parameter design software UG/NX 5.0 is compiled under the environment of visual C++, the model is driven by program, realizes the parameter and series design of drip irrigation emitter, and establishes basis for fluid field analysis for next step.