Experimental study on flow-induced motion and energy conversion for two triangular prisms in tandem arrangement

Abstract

Experimental tests on two tandem triangular prisms were accomplished in synergistic flow-induced motion (FIM) to collect ocean current energy (OCE) with varied spacing ratios and Reynolds number ranges. Typical FIM responses and energy conversion are discussed and presented. The effects of parameters (system stiffness, spacing ratio, and load resistance) were considered to improve the energy harvesting of the system. The main findings can be summarized as follows: 1) with varied spacing ratios between the two tandem prisms, the active power (Pharn) was up to 1.95 times that of the single triangular prism (STP); 2) In general, the harnessed OCE capacity of the upstream triangular prism (UTP) was improved, while the energy harvesting of the downstream triangular prism (DTP) was suppressed by the interaction of the two prisms, 3) In the tests, electricity was generated atU= 0.516 m/s, and the active power, which consistently increased as flow velocity increased, reachedPharn= 32.24 W, with a corresponding efficiency ofηharn= 10.31%; and 4) The best energy conservation performance for harvesting the OCE occurred atL/D= 5, and the optimal load resistance was found atRL= 11 Ω.