Document Type : Research Paper
Ph.D. Student, Department of Irrigation & Drainage. Shahid Chamran University, Ahwaz, Iran.
Professors, Water Sciences Engineering Facualty, Shahid Chamran University, Ahwaz, Iran.
Shahid Chamran University of Ahwaz, Faculty of Water Sciences Engineering
One of the most important factors in trickle irrigation system is selecting the emitter, this is due to the fact that, the drip irrigation function depends on the emitter type and design method. In the present study, performance of 11 types of pressure compensating emitters available on the market, have been investigated regarding their uniformity of discharge. For this purpose, 18 samples of each kind of emitters with nominal discharges 2, 4, 8 and 24 L/hr, were chosen randomly and different discharges were examined in various operating pressures. The experiments were conducted according to ISO 9261, in the Water Sciences Engineering lab of Shahid Chamran University Ahwaz, Iran. The emitters were coded from A1 to M4 respectively. Ten operating pressure levels of 3, 4, 5, 6, 10, 15, 20, 30, 35 and 40 m were used in each sample. Emitters used in the study were classified based on the 3 indexes, emitter exponent (x) in the emitter function (q=khx), determination coefficient (R2) and relative error (Er). The emitter exponent (x) ranged from -0.0067 to -0.4969 which the minimum belongs to C2 and the maximum belongs to C1. The determination coefficient (R2), varied from 0.0007 to 0.609 where the lowest range belongs to M4 and the highest range belongs to D1. The variation of Er was between 0.1 and 34.6 corresponding to E2 and A2 respectively. The results indicated that, regarding pressure compensation, emitter J ranked the best while emitter D1 ranked last.