Dynamic characteristics of a wind-tunnel ohmic heater

An experimental study was conducted to study the effects of flow uniformity on vibration and power generation of a small vertical axis wind turbine (VAWT). Previous studies have confirmed that one of the sources of vibration in the turbine is due to aerodynamic forces, which are due to incident wind. Firstly, understanding vibration is essential before proceeding to the measurements. In this experiment, further understand the vibrations of the turbine in operation, the operating deflection shape (ODS) technique was used. A wind tunnel and flow conditioner were fabricated. Experimental modal analysis (EMA) was conducted, and the dynamic characteristics are gathered. The ODS was conducted for operating the turbine at different speeds, with and without the flow conditioner. Results from EMA and ODS are correlated to explain the behavior of structures. In conclusion, the flow conditioner tested did have a big impact on the response of the structure in terms of vibration up to 30% indifference, but not so much in power generated about 2% indifference.

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A study on dynamic characteristics of the second throat centrebody of transonic wind tunnel

2017 8th International Conference on Mechanical and Aerospace Engineering (ICMAE) ◽

10.1109/icmae.2017.8038675 ◽

2017 ◽

Author(s):

Shen Jiang ◽

Qiu Rong Kai ◽

Ma YueYin ◽

Bao Lu Qiang ◽

Wang Xiao Lei ◽

...

Keyword(s):

Wind Tunnel ◽

Dynamic Characteristics ◽

Transonic Wind Tunnel

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Field Measurements of Dynamic Characteristics and Wind-Induced Response of a Large-Span Roof Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.5349 ◽

2011 ◽

Vol 243-249 ◽

pp. 5349-5355 ◽

Cited By ~ 1

Author(s):

Ji Yang Fu ◽

An Xu ◽

Jiu Rong Wu

Keyword(s):

Wind Tunnel ◽

Dynamic Characteristics ◽

Wind Tunnel Test ◽

Field Measurements ◽

Mode Shapes ◽

Induced Response ◽

Test Results ◽

Large Span ◽

Stochastic Subspace Identification ◽

Roof Structure

This paper presents some selected results obtained from the field measurements of wind effects on Guangzhou International Sports Arena (GISA) during the passage of Typhoon Fanapi in September, 2010. The field data such as wind speed, wind direction and acceleration responses, etc., were simultaneously and continuously recorded during the typhoon. The measured acceleration data are analyzed to obtain the information on dynamic characteristics and wind-induced response of the large-span roof structure. The first four natural frequencies and vibration mode shapes of the roof are identified on the basis of the field measurements using the stochastic subspace identification (SSI) method and comparisons with those calculated from the computational model of the roof are made. The damping ratios of the roof are also identified by the SSI method and compared with those estimated by the random decrement method, and the amplitude-dependent damping characteristics are presented and discussed. Furthermore, the field measurement results are compared with the wind tunnel test results to examine the accuracy of the model test results and the adequacy of the techniques used in wind tunnel tests.

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