Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

The movement of the lifting pipe for deep-sea manganese nodules influences not only its stability but also flow efficiency. In order to investigate the effects, we developed a finite element model considering liquid and structural transients in a deep ocean mining pipe. Two examples are presented for the validation of the developed model by comparing internal fluid pressure and structural displacement. Dynamic responses of fluid and pipe were almost identical compared to the results of literatures cited. Then the model was also used to perform studies on the vibration of a 5,000 m deep-sea hydraulic pumping system and its effects on flow efficiency. The maximum pipe displacement in a deep sea lifting pipe was estimated as 4.785 m but only 0.123 m by internal flow induced vibration. Also, the displacement in the case considering internal flow and deep ocean currents showed almost the similar results. Then for the analysis of the effect of pipe behaviors on internal flow, we compared the fluid pressure of the model with that of the case in which pipe was supported rigidly. From the results, the effect of pipe movement on inflow efficiency was found to be negligible. However, we need to analyze the influence caused by additional external forces such as the motion of mining ship/buffer in the future work.