To address issues such as high soil backfilling rates and difficulty in maintaining the trench shape during the operation of pineapple strip-rotary cultivators, we designed a V-shaped soil-dividing device. Structural modelling was performed using SolidWorks 2022 by establishing force analysis equations for the soil-dividing device and soil motion trajectory equations. A dynamic simulation model based on the discrete element method was constructed using the EDEM software to determine the structural parameters of the soil-dividing device. Stress analysis conducted using the ANSYS software verified that the structural strength of the soil-dividing device met the application requirements. To optimize operational parameters further, a four-factor, five-level orthogonal rotational combination field trial was designed using the central composite response surface method in Design-Expert 12. The installation distance, V-angle, blade roller speed, and forward speed were defined as the experimental factors, with the soil backfilling rate as the evaluation indicator. We analyzed the effects of various factor interactions on the soil backfilling rate. The experimental results indicated that the minimum soil backfilling rate of 38.12%, which is satisfactory for pineapple planting trenching requirements, was achieved at a V-angle of 30°, forward speed of 3.7 km/h, blade roller speed of 290 r/min, and installation distance of 125 mm. This study has significant implications for advancing the mechanization of pineapple cultivation.
Haitian Sun, Wei Zhang, Hongxuan Wang et al.· PLoS ONE· 0 citations
This work presents a surrogate-assisted multi-objective aerodynamic optimization of a centrifugal air pump through joint reshaping of the impeller blade and diffuser vane. A 22-dimensional design space is constructed using Bézier-based recambering, leading-edge lean, and independently varied hub and shroud stagger angles. The objective is to improve the stage pressure rise and efficiency while controlling the axial force through enhanced impeller–diffuser matching. Single-objective, bi-objective, and tri-objective optimizations are performed. The Pareto fronts reveal clear tradeoffs in that the total pressure rise and efficiency are positively correlated at moderate loading but become conflicting at high loading, and higher pressure rise is accompanied by increased axial force. The selected optimized model achieves simultaneous improvements in both the stage total pressure rise and efficiency relative to the baseline model, with the axial force coefficient remaining comparable to the baseline. Sobol sensitivity analysis identifies the diffuser vane camberline parameters as the dominant group for stage-level performance, the shroud stagger angle and hub blade camberline as co-dominant for the impeller work input, and reveals pervasive nonlinear cross-component coupling that provides statistical justification for the joint impeller–diffuser optimization strategy. SHapley Additive Explanations analysis corroborates these findings and further quantifies that the combined diffuser vane camberline contribution to stage efficiency exceeds 44%, while the axial force coefficient is governed nearly uniformly by all geometric groups. Analysis on the internal flow mechanisms demonstrates that the streamwise allocation of blade lean is the key for stage performance improvement. Negative lean near the impeller inlet enhances work input, while positive lean downstream suppresses low-energy fluid accumulation in the suction surface–shroud corner and weakens the jet–wake structure. In the diffuser, positive vane lean alleviates total pressure losses in the pressure-side–hub corner by establishing a favorable spanwise pressure gradient. These findings provide design guidelines for low-speed centrifugal turbomachinery aerodynamic optimization through coordinated blade stacking and recambering.
Peng Sun, Mingze Yuan, Wei Zhang et al.· The Physics of Fluids· 0 citations