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Vestas engineers checked and repaired the wind turbine brake on the morning of 22 February 2008. At the last routine inspection it was noted that the main gear of the turbine was also making unusual noises and a sophisticated endoscopic inspection of the gear was planned, but as result of its high cost it was not undertaken immediately.
Acoustic sources within the "jet pipe" also contribute to the noise, mainly at lower speeds, which include combustion noise, and sounds produced by interactions of a turbulent stream with fans, compressors, and turbine systems. [1] The jet mixing sound is created by the turbulent mixing of a jet with the ambient fluid, in most cases, air.
A roof turbine ventilator, colloquially known as a 'Whirly Bird' is an application of wind driven ventilation. Passive ventilation is the process of supplying air to and removing air from an indoor space without using mechanical systems.
The new version had a four-stage low-pressure compressor driven by a two-stage turbine and an eight stage high-pressure compressor driven by another two-stage turbine. Now known by the Ministry of Supply designation as the RCo.2 , design work was completed in January 1950 and the first example ran for the first time in July 1952 at 10,000 ...
[1] Small wind turbines are defined as being of up to 200 m 2 swept area and a somewhat simplified IEC 61400-2 standard addresses these. It is also possible to use the IEC 61400-1 standard for turbines of less than 200 m 2 swept area. The standards for loads and noise are used in the development of prototypes at the Østerild Wind Turbine Test ...
Robins are a much loved Christmas icon, but wind turbines installed in their habitat are affecting their song, with worrying consequences. Robin hushed: wind turbines are making songbirds change ...
Exhaust resonators are also used to reduce potentially loud engine noise where the dimensions are calculated so that the waves reflected by the resonator help cancel out certain frequencies of sound in the exhaust. In some two-stroke engines, a Helmholtz resonator is used to remove the need for a reed valve.
An attic fan installed underneath a roof. A powered attic ventilator, or attic fan, is a ventilation fan that regulates the heat level of a building's attic by exhausting hot air. A thermostat is used to automatically turn the fan off and on, while sometimes a manual switch is used. An attic fan can be gable mounted or roof mounted. Additional ...