Numerical investigation on flow induced vibration performance of flow-around structures with different angles of attack

The concept of energy harvesting based on flow-induced vibration (FIV) used in a new application field of long-distance transport pipelines is proposed in this paper, the fluid kinetic energy in pipelines is harvested and converted into electricity, to provide uninterrupted power for sensors along pipelines, realizing remote monitoring and management of pipelines at lower cost. This paper aims to find the shape features of flow-around structure that enhance FIV and harvest energy more effectively, giving design references for the geometrical shape of energy harvester. To independently study the influence of vortex shedding position on the FIV performance, the FIV responses, wake patterns and energy conversion efficiency of structures with different angles of attack that have different vortex shedding positions are numerically studied versus frequency ratios in this paper. Results show that the more forward vortex shedding position determines the higher FIV response, and the criterion for the shape feature of structure on its upstream side that enhance FIV is summarized. Results also show the energy conversion efficiency is the result of FIV amplitude, oscillating frequency and fluid force, which isn't completely positively correlated with FIV amplitude. Each structure obtains the maximum energy conversion efficiency at frequency ratio of 0.7. •Effect of separating position on vibration performance is independently studied.•More forward separating position leads to higher flow-induced vibration response.•Criterion on shape of structure for enhancing vibration is summarized from result.•Energy conversion efficiency is not positively correlated with amplitude response.•Result give guide for shape design of energy harvester used in long-distance pipe.