Turbulent flows in two hydro-turbines of hose reel irrigator respectively with two entries, i.e. nozzle and spiral case, were investigated numerically using SST k-ω turbulence model to uncover the differences between internal flow field characteristics and hydraulic performance caused by two different kinds of entries. The predicted hydraulic performance of the turbine with nozzle was validated with the corresponding experimental data available. It is indicated that large scale vortex and strong leakage flow cross the blade side tip clearance existes in the impeller of the turbine with nozzle entry. For the turbine with spiral entry, the pressure and streamlines inside the impeller are distributed relatively uniformly, no significant difference in the leakage flow pattern along the circumferential direction is noticed. It is found that the percentage of each component hydraulic loss to the total hydraulic loss across the turbine with nozzle remains constant basically at various flow rates, especially, the hydraulic loss in the impeller accounts for 55% of the total hydraulic loss. For the turbine with spiral case, the hydraulic loss in each component varies with flow rate. The performance curves of two turbines show nearly the same variation tendency, but the efficiency of the turbine with spiral case is 18%-22% higher than that of the turbine with nozzle at the same flow rate, especially the best efficiency of the former is 59.6% in comparison with 35.6% of the latter. These results can provide a reference for hydraulic design and structural improvement of hydro-turbine in hose reel irrigators.
CHEN Wei-Sheng-,LI Yao-Jun-*,YAN Hai-Jun- et al. Numerically simulated effects of entry on hydraulic performance of hydro-turbine in hose reel irrigators[J]. Journal of Drainage and Irrigation Machinery Engin, 2018, 36(9): 845-850.
YUAN Shouqi, NIU Guoping, TANG Yue, et al. Experiment and numerical estimation of performance of hydraulic turbine of JP50 reel sprinkle[J]. Journal of drainage and irrigation machinery engineering, 2014, 32(7): 553-557.(in Chinese)
LI Yaojun, ZHANG Zhenzhou, YAN Haijun, et al. Hydraulic performance analysis and optimization for water turbine of JP75 hose reel irrigation machine[J]. Transactions of the CSAM, 2018, 49(1): 100-107.(in Chinese)
WANG Fujun. Research progress of computational mo-del for rotating turbulent flow in fluid machinery[J]. Transactions of the CSAM, 2016, 47(2): 1-14.(in Chinese)
JIANG W, LI G, LIU P F, et al. Numerical investigation of influence of the clocking effect on the unsteady pressure fluctuations and radial forces in the centrifugal pump with vaned diffuser [J]. International communications in heat & mass transfer, 2016, 71:164-171.