The effects of Venturi structural parameters on its hydraulic performance were studied, which provided theoretical basis for the\r\ndesign of Venturi injector. With an inlet diameter of 50 mm, based on the method of computational fluid dynamics (CFD),\r\nthe effects of the structural parameters (such as throat taper, throat contraction ratio, and throat length) on their hydraulic\r\nperformance (such as outlet faceted average velocity, minimum pressure, and critical pressure) were studied under different inlet\r\npressures and pressure differences between inlet and outlet. A power function relationship existed between the mean velocity in\r\noutlet section and pressure difference, with an approximate flow stance index of 0.53. Minimum pressure occurred in the throat\r\ninlet wall and there was a linear relationship between the minimum pressure and the pressure difference at the inlet and outlet. The\r\nthroat contraction ratio was the main factor on the effect of Venturi injector performance, which was positively correlated with\r\noutlet velocity, negatively to critical pressure, the minimal in-tube pressure, coefficient of local head loss, and fertilizer absorption\r\nratio. For designing Venturi injector, contraction ratio should be reasonably selected according to the coefficient of local head loss\r\nand fertilizer absorption ratio.
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