CFD analysis of energy harvesting from flow induced vibration of a circular cylinder with an attached free-to-rotate pentagram impeller

Hongjun Zhu, Ying Zhao, Tongming Zhou

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

A new converter consisting of an elastically mounted circular cylinder and a free-to-rate pentagram impeller is proposed to harness hydrokinetic energy from water currents. The vibration energy of the cylinder and the rotation energy of the impeller are harvested simultaneously. The two-way fluid-structure interaction simulations are employed to investigate the vibration and rotation response of the converter. The simulated Reynolds number range is 14,000 < Re < 80,000, falling in the TrSL2 (transition of shear layer 2) and TrSL3 regimes. The results indicate that the vibration amplitude of the converter increases with increasing of the flow velocity, and the growth becomes faster at high reduced velocity (Ur). The presence and rotation of the impeller contribute to the hydrodynamic instability of the system at Ur ≥ 9, where the rotational direction is constantly changing. The hydrodynamic instability brings about a wider flow wake and unstable vortex shedding, resulting in the enhancement of vibration and the increase of power. For such a rotation symmetric structure, increasing the torsional friction does not play a significant role in suppressing the hydrodynamic instability. The estimated power generating capacity is sensitive to flow velocity and additional damping ratio. The average power efficiency is about 22.6%, and the power density for a 5D × 5D staggered configuration with ζharn of 0.031374 can reach 885.53 W/m3.

Original languageEnglish
Pages (from-to)304-321
Number of pages18
JournalApplied Energy
Volume212
DOIs
Publication statusPublished - 15 Feb 2018

Fingerprint

Energy harvesting
Circular cylinders
Vibrations (mechanical)
vibration
Computational fluid dynamics
Hydrodynamics
hydrodynamics
Flow velocity
flow velocity
energy
fluid-structure interaction
vortex shedding
Fluid structure interaction
Vortex shedding
Reynolds number
damping
friction
Damping
Friction
analysis

Cite this

@article{cdcd7007e7be4b1b90c122d5d2d6878e,
title = "CFD analysis of energy harvesting from flow induced vibration of a circular cylinder with an attached free-to-rotate pentagram impeller",
abstract = "A new converter consisting of an elastically mounted circular cylinder and a free-to-rate pentagram impeller is proposed to harness hydrokinetic energy from water currents. The vibration energy of the cylinder and the rotation energy of the impeller are harvested simultaneously. The two-way fluid-structure interaction simulations are employed to investigate the vibration and rotation response of the converter. The simulated Reynolds number range is 14,000 < Re < 80,000, falling in the TrSL2 (transition of shear layer 2) and TrSL3 regimes. The results indicate that the vibration amplitude of the converter increases with increasing of the flow velocity, and the growth becomes faster at high reduced velocity (Ur). The presence and rotation of the impeller contribute to the hydrodynamic instability of the system at Ur ≥ 9, where the rotational direction is constantly changing. The hydrodynamic instability brings about a wider flow wake and unstable vortex shedding, resulting in the enhancement of vibration and the increase of power. For such a rotation symmetric structure, increasing the torsional friction does not play a significant role in suppressing the hydrodynamic instability. The estimated power generating capacity is sensitive to flow velocity and additional damping ratio. The average power efficiency is about 22.6{\%}, and the power density for a 5D × 5D staggered configuration with ζharn of 0.031374 can reach 885.53 W/m3.",
keywords = "Energy harvesting, Free-to-rotate, Impeller, Power, Vortex induced vibration",
author = "Hongjun Zhu and Ying Zhao and Tongming Zhou",
year = "2018",
month = "2",
day = "15",
doi = "10.1016/j.apenergy.2017.12.059",
language = "English",
volume = "212",
pages = "304--321",
journal = "Applied Energy",
issn = "0306-2619",
publisher = "Elsevier",

}

CFD analysis of energy harvesting from flow induced vibration of a circular cylinder with an attached free-to-rotate pentagram impeller. / Zhu, Hongjun; Zhao, Ying; Zhou, Tongming.

In: Applied Energy, Vol. 212, 15.02.2018, p. 304-321.

Research output: Contribution to journalArticle

TY - JOUR

T1 - CFD analysis of energy harvesting from flow induced vibration of a circular cylinder with an attached free-to-rotate pentagram impeller

AU - Zhu, Hongjun

AU - Zhao, Ying

AU - Zhou, Tongming

PY - 2018/2/15

Y1 - 2018/2/15

N2 - A new converter consisting of an elastically mounted circular cylinder and a free-to-rate pentagram impeller is proposed to harness hydrokinetic energy from water currents. The vibration energy of the cylinder and the rotation energy of the impeller are harvested simultaneously. The two-way fluid-structure interaction simulations are employed to investigate the vibration and rotation response of the converter. The simulated Reynolds number range is 14,000 < Re < 80,000, falling in the TrSL2 (transition of shear layer 2) and TrSL3 regimes. The results indicate that the vibration amplitude of the converter increases with increasing of the flow velocity, and the growth becomes faster at high reduced velocity (Ur). The presence and rotation of the impeller contribute to the hydrodynamic instability of the system at Ur ≥ 9, where the rotational direction is constantly changing. The hydrodynamic instability brings about a wider flow wake and unstable vortex shedding, resulting in the enhancement of vibration and the increase of power. For such a rotation symmetric structure, increasing the torsional friction does not play a significant role in suppressing the hydrodynamic instability. The estimated power generating capacity is sensitive to flow velocity and additional damping ratio. The average power efficiency is about 22.6%, and the power density for a 5D × 5D staggered configuration with ζharn of 0.031374 can reach 885.53 W/m3.

AB - A new converter consisting of an elastically mounted circular cylinder and a free-to-rate pentagram impeller is proposed to harness hydrokinetic energy from water currents. The vibration energy of the cylinder and the rotation energy of the impeller are harvested simultaneously. The two-way fluid-structure interaction simulations are employed to investigate the vibration and rotation response of the converter. The simulated Reynolds number range is 14,000 < Re < 80,000, falling in the TrSL2 (transition of shear layer 2) and TrSL3 regimes. The results indicate that the vibration amplitude of the converter increases with increasing of the flow velocity, and the growth becomes faster at high reduced velocity (Ur). The presence and rotation of the impeller contribute to the hydrodynamic instability of the system at Ur ≥ 9, where the rotational direction is constantly changing. The hydrodynamic instability brings about a wider flow wake and unstable vortex shedding, resulting in the enhancement of vibration and the increase of power. For such a rotation symmetric structure, increasing the torsional friction does not play a significant role in suppressing the hydrodynamic instability. The estimated power generating capacity is sensitive to flow velocity and additional damping ratio. The average power efficiency is about 22.6%, and the power density for a 5D × 5D staggered configuration with ζharn of 0.031374 can reach 885.53 W/m3.

KW - Energy harvesting

KW - Free-to-rotate

KW - Impeller

KW - Power

KW - Vortex induced vibration

UR - http://www.scopus.com/inward/record.url?scp=85037974266&partnerID=8YFLogxK

U2 - 10.1016/j.apenergy.2017.12.059

DO - 10.1016/j.apenergy.2017.12.059

M3 - Article

VL - 212

SP - 304

EP - 321

JO - Applied Energy

JF - Applied Energy

SN - 0306-2619

ER -