Numerical flow simulation and optimum channel design of drip irrigation emitter

Traditional drip irrigation emitter with small diameter labyrinth channel is vulnerable to clogging by the debris in water, and the phenomena may partly be attributed to the stagnant regions and vortices existing in the flow field within the channels. A new design scheme of self-washing emitter is presented. Numerical simulation is first conducted, and then channel curves and shapes are corrected and optimized based on the calculated streamlines. The new design can effectively eliminate the vortices and low velocity and stagnant regions within the emitter pore. It is found that, compared with laminar flow, turbulent flow assumes an uniform velocity profile in the cross section of the channel and higher velocities even in the region close to channel wall, and therefore turbulent flow would have better anti-clogging characteristics. The pressure drop across the optimized channel is significantly reduced, and the reduction can be compensated by increasing the channel length and the flow rate through the channel.