TY - JOUR
T1 - Planform geometry effects of piezoelectric wind energy harvesting composite inverted flags
AU - Yang, Kaidong
AU - Nabawy, Mostafa R.A.
AU - Cioncolini, Andrea
AU - Revell, Alistair
AU - AlGhrairy, Saad
N1 - Publisher Copyright:
© 2021 The Author(s). Published by IOP Publishing Ltd Printed in the UK
PY - 2021/11
Y1 - 2021/11
N2 - Energy harvesting devices based on the inverted flag configuration have recently attracted attention as a viable option to power small electronics and remote wireless sensors from wind excitation. Despite showing high potential, relatively little research has considered how the dynamics and power generation performance of these devices vary with planform geometry. This study considers composite inverted flags constructed using flexible polyvinylidene difluoride strips as active elements sandwiching a stainless-steel shim as elastic structural support, a configuration allowing for enhanced ability to tailor mechanical and geometrical properties (and hence responses) of the flag. We explore the effect of three key parameters (planform aspect ratio, mass ratio, second moment of area) on flag dynamics (amplitude, flapping frequency) and operational characteristics (power, velocity range). Twelve flags have been manufactured and tested under controlled wind excitation, selected to cover aspect ratios in the range of 0.9-7 and mass ratios in the range of 7-14. Our results expose a number of useful insights into how these devices perform. First, we show that for a given mass ratio, flapping amplitude, frequency, power, and power density are all inversely proportional to aspect ratio and proportional to second moment of planform area. Second, we show that second moment of planform area is a better indicator parameter to assess the flags performance, as compared to the aspect ratio. Third, we show that as mass ratio increases higher power densities and wider operational velocity ranges are allowed; however, this is on the expense of the flag being more sensitive to variations in operating conditions and the possibility of experiencing some unfavourable motion behaviour such as the 'one-sided' low-amplitude high-frequency low-power flapping mode.
AB - Energy harvesting devices based on the inverted flag configuration have recently attracted attention as a viable option to power small electronics and remote wireless sensors from wind excitation. Despite showing high potential, relatively little research has considered how the dynamics and power generation performance of these devices vary with planform geometry. This study considers composite inverted flags constructed using flexible polyvinylidene difluoride strips as active elements sandwiching a stainless-steel shim as elastic structural support, a configuration allowing for enhanced ability to tailor mechanical and geometrical properties (and hence responses) of the flag. We explore the effect of three key parameters (planform aspect ratio, mass ratio, second moment of area) on flag dynamics (amplitude, flapping frequency) and operational characteristics (power, velocity range). Twelve flags have been manufactured and tested under controlled wind excitation, selected to cover aspect ratios in the range of 0.9-7 and mass ratios in the range of 7-14. Our results expose a number of useful insights into how these devices perform. First, we show that for a given mass ratio, flapping amplitude, frequency, power, and power density are all inversely proportional to aspect ratio and proportional to second moment of planform area. Second, we show that second moment of planform area is a better indicator parameter to assess the flags performance, as compared to the aspect ratio. Third, we show that as mass ratio increases higher power densities and wider operational velocity ranges are allowed; however, this is on the expense of the flag being more sensitive to variations in operating conditions and the possibility of experiencing some unfavourable motion behaviour such as the 'one-sided' low-amplitude high-frequency low-power flapping mode.
KW - Energy harvesting
KW - Experiment
KW - Inverted flag
KW - PVDF
KW - Piezoelectric
KW - Wind
UR - http://www.scopus.com/inward/record.url?scp=85119206028&partnerID=8YFLogxK
U2 - 10.1088/1361-665X/ac2b8a
DO - 10.1088/1361-665X/ac2b8a
M3 - 文章
AN - SCOPUS:85119206028
SN - 0964-1726
VL - 30
JO - Smart Materials and Structures
JF - Smart Materials and Structures
IS - 11
M1 - 115014
ER -