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Infästning av byggnadsmonterat vindkraftverk

Areschoug, Peter LU (2011) In TVSM-5000 VSM820 20102
Structural Mechanics
Abstract
In order to better utilize the wind in urban areas, small-scale wind-turbines can be retro-fitted on existing buildings. However, wind-turbines are as structures very prone to oscillate. If the turbines would be mounted with a stiff connection, these vibrations would transmit to the building structure where high-frequency vibrations will transmit
as structure-borne noise, and low-frequency vibrations could damage the structure.

In this thesis, the vibrations due to the rotor blades’ interaction with the air-stream passing through the rotor’s swept area are simulated. The simulations are conducted on a horizontal axis wind turbine, with three rotor blades with 2.6 m radius, and a variable rotor frequency. The ambient conditions are... (More)
In order to better utilize the wind in urban areas, small-scale wind-turbines can be retro-fitted on existing buildings. However, wind-turbines are as structures very prone to oscillate. If the turbines would be mounted with a stiff connection, these vibrations would transmit to the building structure where high-frequency vibrations will transmit
as structure-borne noise, and low-frequency vibrations could damage the structure.

In this thesis, the vibrations due to the rotor blades’ interaction with the air-stream passing through the rotor’s swept area are simulated. The simulations are conducted on a horizontal axis wind turbine, with three rotor blades with 2.6 m radius, and a variable rotor frequency. The ambient conditions are considered to be normal; during such the wind speeds do not exceed the wind turbines nominal speed. The simulations are conducted in Matlab, with much help of CALFEM.

The results show that both high and low frequency oscillations arise, as the tower is excited in its natural frequencies. The powerful oscillations are due to the tower damming effect. In building acoustics, vibrational problems are usually dealt with by creating a mass-spring-system with an eigenfrequency well below 2-3 times the exciting frequency. There is however a great disadvantage with this method; the massspring-system’s ability to isolate low-frequency vibrations is dependent on a existing elastic mounting. The rotations of the foundation that would arise due to a elastic mounting are not desireable, as the wind turbine is subjected to aeroelastic vibrations and a lesser power production.

When the turbines are simulated mounted on a foundation that in the static case result in a reasonable rotation, the results show that it is not possible to isolate the joist from the vibrations. If a wind turbine nonetheless should be building mounted, the foundation should be as large as possible. (Less)
Please use this url to cite or link to this publication:
author
Areschoug, Peter LU
supervisor
organization
alternative title
Structural dynamic simulation of a building mounted wind turbine.
course
VSM820 20102
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
Urban wind power, building-mounted wind turbines, BUWT
publication/series
TVSM-5000
report number
TVSM-5179
ISSN
0281-6679
language
Swedish
id
3202841
date added to LUP
2012-11-26 12:42:40
date last changed
2012-11-26 12:42:40
@misc{3202841,
  abstract     = {In order to better utilize the wind in urban areas, small-scale wind-turbines can be retro-fitted on existing buildings. However, wind-turbines are as structures very prone to oscillate. If the turbines would be mounted with a stiff connection, these vibrations would transmit to the building structure where high-frequency vibrations will transmit
as structure-borne noise, and low-frequency vibrations could damage the structure.

In this thesis, the vibrations due to the rotor blades’ interaction with the air-stream passing through the rotor’s swept area are simulated. The simulations are conducted on a horizontal axis wind turbine, with three rotor blades with 2.6 m radius, and a variable rotor frequency. The ambient conditions are considered to be normal; during such the wind speeds do not exceed the wind turbines nominal speed. The simulations are conducted in Matlab, with much help of CALFEM.

The results show that both high and low frequency oscillations arise, as the tower is excited in its natural frequencies. The powerful oscillations are due to the tower damming effect. In building acoustics, vibrational problems are usually dealt with by creating a mass-spring-system with an eigenfrequency well below 2-3 times the exciting frequency. There is however a great disadvantage with this method; the massspring-system’s ability to isolate low-frequency vibrations is dependent on a existing elastic mounting. The rotations of the foundation that would arise due to a elastic mounting are not desireable, as the wind turbine is subjected to aeroelastic vibrations and a lesser power production.

When the turbines are simulated mounted on a foundation that in the static case result in a reasonable rotation, the results show that it is not possible to isolate the joist from the vibrations. If a wind turbine nonetheless should be building mounted, the foundation should be as large as possible.},
  author       = {Areschoug, Peter},
  issn         = {0281-6679},
  keyword      = {Urban wind power,building-mounted wind turbines,BUWT},
  language     = {swe},
  note         = {Student Paper},
  series       = {TVSM-5000},
  title        = {Infästning av byggnadsmonterat vindkraftverk},
  year         = {2011},
}