Investigation of Head Loss along Drip Emitter Channel by Using Computational Fluid Dynamics

摘要

It is difficult to investigate how to achieve biggest head loss of the drip emitter channel due to the channel's minor and complicated structure. Four types of Super Typhoon emitter with trapezoidal channel were selected out for the investigation of the head loss along the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. First, four different types of drip emitter and their channel models were modeled; then, three kinds of turbulent model provided by the commercial software Fluent 6.3 were used to get micro-field of channel, eight groups of working pressure named 2, 4, 6, 8, 10, 12, 14, 16mH20 were applied for the simulation; at last, the experiments between pressure and dischargewere conducted, and the pressure corresponding to the simulation were used. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation ofk-co and RSM model is 5, 4.5 respectively, but the solving efficiency of the k-co model is obviously higher than that of the RSM model. The effect of working pressure on the distribution is evident when the water head is lower than 6mH_2O, and the head loss distribution will keep stable when the working pressure is higher than 6mH20 except that near the inlet and outlet area. This may because the water flow inside channel except the zone near inlet and outlet is full turbulence when the working pressureis higher than 6mH_2O.