Based on the structural parameters of Venturi injector with non-axis-symmetric structure(eccentricity upward)proposed by some researchers and related laboratory measurement data, CFD numerical simulation method was used to analyze the reason why there were differences in performance variables such as fertilizer flow rate, internal flow field and cavitation parameter in the Venturi injectors with non-axis-symmetrical and axis-symmetrical structures. Results showed that the simulated performance agreed well with the laboratory test data. At the same fertilizer flow rate, the Venturi injector with non-axis-symmetric structure has a significantly lower energy loss compared with that with axis-symmetrical structure, especially the pressure loss could be reduced by(25-35)%. The negative pressure zone in the Venturi injector with axis-symmetrical structure is distributed around the throat, but in the injector with non-axis-symmetric structure, however, it is in the half ring, located in the lower part of the throat. As a result, the cavitation zone is smaller and beneficial to increase of suction flow rate under the same pressure difference. In the non-axis-symmetrical Venturi injector, the contraction and diffusion parts are connected smoothly in the upper part of throat, so that the collisions between fluid particles in various directions are little, the resulted energy loss is relatively small, and the reverse flow region in the diffuser is also in a small size.
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