Influence of Constraint Method of Elastic Diaphragm on Numerical Simulation of Pressure-Compensating Emitter

Abstract

HighlightsDeformation of the elastic diaphragm can affect the flow field characteristics of a pressure-compensating emitter.The contact constraint method’s simulation of the elastic diaphragm were consistent with its actual deformation.The contact constraint method can reduce the relative errors between simulated and experimental results.Abstract. Numerical simulation is an important method for revealing the working principle and optimizing the design of drip emitters. The hydraulic performance of pressure-compensating (PC) emitters is determined by the interaction between the elastic diaphragm and the flow field; therefore, correct deformation of the elastic diaphragm is one of the factors determining the accuracy of numerical simulation of PC emitters. This study investigated the effects of three constraint methods of the elastic diaphragm on the numerical simulation of PC emitters. The three methods were fully fixed constraint (FFC), upper surface fixed constraint (UFC), and contact constraint (CC). Fluid-structure interaction (FSI) simulation was used to analyze the deformation characteristics of the elastic diaphragm, the flow field characteristics, and the flow rate of the PC emitter. The simulated diaphragm deformation and flow rates were compared with the results of a visual experiment and a hydraulic performance experiment, respectively. The simulation results showed that the constraint method affected the diaphragm deformation and flow field of the PC emitter. In comparing the simulation results with the experimental results, the CC method had the highest accuracy among the three constraint methods, but an extremely long computation time was required. The FFC method had the lowest accuracy but required less computation time. The accuracy of the UFC method was lower than CC and higher than FFC, but its computation time decreased by 60.03% compared with CC. This study provides a foundation for further research on the numerical simulation and design of PC emitters. Keywords: Constraint method, Deformation characteristics, Flow field characteristics, Fluid-structure interaction, Visual experiment.