Characterization and performance optimization of deep-sea polymetallic nodule mining considering changes in the traveling posture of mining vehicles

With the advancement of deep-sea mining technology, long-distance continuous operation and extraction represent the key technical challenges for the commercialization of deep-sea mineral resources. This paper quantifies the degree of reduction in mining performance under different mine vehicle orientations and conducts research on flow field optimization. The results indicate that when the inclination angle is ≤3°, the Coandă jet maintains a stable wall-attached flow, with the collection efficiency remaining above 70%. As the inclination angle increases to 8°–14°, the pressure-induced flow structure generated by wall adhesion progressively deteriorates. The low-pressure region significantly narrows, and collection efficiency drops below 40%. This demonstrates its high sensitivity to attitude changes. Therefore, this study proposes a flow field optimization method aimed at enlarging the effective fluid action zone. The results show that after optimizing the flow field structure, the momentum coupling within the channel is significantly enhanced, and the wall-attached flow region is expanded. Under the 3° condition, the collection efficiency increases from 20% to 98%. Based on this, a dimensionless ratio parameter k was introduced to characterize the relationship between the vehicle posture, traveling parameters, and jet operating conditions. The results show that k effectively distinguishes the collection characteristics under different working conditions: when k < 50, the collection efficiency is significantly low, whereas when k ≥ 150, the efficiency approaches saturation. Therefore, in practical engineering design, k ≥ 150 should be ensured to achieve efficient mining. This study provides both theoretical and technical support for achieving efficient collection performance of deep-sea mining equipment under complex seabed conditions.