Find in Library

In many special agricultural environments, many wireless sensors have a problem of power supply selection. Energy harvesting in the agricultural environment based on vortex-induced vibration (VIV) has the potential to solve the problem. In this paper, an energy harvester based on the VIV is designed in an agricultural environment. Relevant parameters of the harvester are studied with wind tunnel experiment to improve the efficiency of energy conversation. The results show that: (i) For large mass ratio, <inline-formula><math display="inline"><semantics><mrow><msup><mi>m</mi><mo>*</mo></msup><mo>≫</mo><mn>1</mn></mrow></semantics></math></inline-formula>, and the same mass ratio <inline-formula><math display="inline"><semantics><mrow><msup><mi>m</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula>, the smaller the damping ratio <inline-formula><math display="inline"><semantics><mi>ζ</mi></semantics></math></inline-formula>, the larger the normalized amplitude <inline-formula><math display="inline"><semantics><mrow><msup><mi>A</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula>, the larger the maximum efficiency <inline-formula><math display="inline"><semantics><mi>η</mi></semantics></math></inline-formula> of VIV energy harvesting; (ii) <inline-formula><math display="inline"><semantics><mrow><msup><mi>m</mi><mo>*</mo></msup><mo>≫</mo><mn>1</mn></mrow></semantics></math></inline-formula>, and under a certain range of Reynolds numbers, the smaller the mass-damping parameter <inline-formula><math display="inline"><semantics><mrow><msup><mi>m</mi><mo>*</mo></msup><mi>ζ</mi></mrow></semantics></math></inline-formula>, the larger the normalized amplitude <inline-formula><math display="inline"><semantics><mrow><msup><mi>A</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula>, the larger the maximum and average efficiency <inline-formula><math display="inline"><semantics><mi>η</mi></semantics></math></inline-formula> of VIV energy harvesting. (iii) <inline-formula><math display="inline"><semantics><mrow><msup><mi>m</mi><mo>*</mo></msup><mo>≫</mo><mn>1</mn></mrow></semantics></math></inline-formula>, the larger the mass ratio <inline-formula><math display="inline"><semantics><mrow><msup><mi>m</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula>, the larger the range of resonance; the normalized frequency <inline-formula><math display="inline"><semantics><mrow><msup><mi>f</mi><mo>*</mo></msup><mo>≃</mo><mn>1</mn></mrow></semantics></math></inline-formula>, the stable VIV locked state appears. The research results can provide references for the design of VIV energy harvesters in agricultural environments.