SIMULATING EMITTER CLOGGING IN A MICROIRRIGATION SUBUNIT

Abstract

A mathematical model was developed to simulate the effects of emitter clogging on subunit hydraulics. The modelconsists of a set of equations based on fundamental hydraulic principles and inlet lateral discharge relationships, and usesa nonlinear equation solver. The model was used to simulate different clogging rates (0% to 100%) and different clogginglocations within the subunit. Pressure head was monitored at the pump, manifold inlet, manifold midpoint, and manifolddownstream end. The results of the study indicate that to reasonably detect clogging rate and location, the pump pressure headvalue and manifold pressure head profile need to be monitored. Pressure transducers are therefore needed at the pump,manifold inlet point, and manifold endpoint. Model results were verified by using experimental data collected in a previousstudy. The RMSE was found to be 0.13 kPa between model results and experimental data at the upstream point of the manifold,and 1.11 kPa at the downstream end of the manifold. Clogging was found to decrease inlet lateral discharge for cloggedlaterals and increase the lateral inlet discharge for unclogged laterals. In addition, pump response to clogging was found tobecome progressively smaller as the clogging location moved further from the pump.