Sensitivity Study of Contraction Flow for Boundary-Layer Validation Wind Tunnel

2019 ◽  
Author(s):  
Mark Blanco ◽  
Jason Battiato ◽  
Kevin J. Disotell
2021 ◽  
pp. 108043
Author(s):  
Huai-Yu Zhong ◽  
Chao Lin ◽  
Yang Sun ◽  
Hideki Kikumoto ◽  
Ryozo Ooka ◽  
...  
Keyword(s):  

2020 ◽  
Vol 32 (12) ◽  
pp. 125120
Author(s):  
María Jiménez-Portaz ◽  
Luca Chiapponi ◽  
María Clavero ◽  
Miguel A. Losada

1978 ◽  
Vol 100 (1) ◽  
pp. 91-96 ◽  
Author(s):  
V. de Brederode ◽  
P. Bradshaw

Measurements in the entry region of a square duct (specifically, a wind-tunnel working section) show that the direct effect of stress-induced secondary flows in the corners on the center-plane boundary layer is negligible for boundary layers thinner than about one-fourth of the duct width. Further, the effects of streamwise pressure gradient and of quasi-collinear lateral convergence tend to cancel so that the velocity profiles and skin friction are quite close to those on a flat plate. This shows that the boundary layer on the floor of a wind tunnel of constant, square cross section can be used to simulate a flat-plate flow even when the boundary layer thickness is as large as one-fourth of the tunnel height.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Michał Lipian ◽  
Maciej Karczewski ◽  
Krzysztof Olasek

AbstractThe Diffuser Augmented Wind Turbine (DAWT) is an innovative mean to increase the power harvested by wind turbine. By encompassing the rotor with a diffusershaped duct it is possible to increase the flow speed through the turbine by about 40-50%. The study presents the development of a numerical model and its validation by the experiments performed in the wind tunnel of the Institute of Turbomachinery, TUL. Then, the numerical model is used for the geometry sensitivity study to optimize the shape of a diffuser. The paper presents that the DAWT technology has the potential to even double the power outcome of wind turbine when compared to a bare rotor version.


2018 ◽  
Vol 22 (5) ◽  
pp. 1194-1210 ◽  
Author(s):  
XX Cheng ◽  
X Chen ◽  
YJ Ge ◽  
H Jiang ◽  
L Zhao

The traditional atmospheric boundary layer wind tunnel model test practice employs wind fields, the flow characteristics of which are in accordance with the empirical formulae of the atmospheric turbulence presented in Codes of Practice and monographs. However, the empirical formulae presented in Codes of Practice and monographs cannot truthfully reflect the high variations of the realistic atmospheric turbulence which sometimes aggravates wind effects on structures. Based on model tests conducted in a multiple-fan actively controlled wind tunnel, it is found that most wind effects on large cooling towers change monotonically with the increase in free-stream turbulence, and the model test results are more unfavorable for a flow field of low turbulence intensity than for a flow field of high turbulence intensity with respect to the measured coherences. Thus, a new atmospheric boundary layer wind tunnel simulation methodology for wind effects on circular cylindrical structures is proposed to overcome the deficiency of the traditional atmospheric boundary layer wind tunnel model tests. The new simulation methodology includes the simulation of two realistic atmospheric boundary layer flow fields with the highest and the lowest turbulence intensities in the wind tunnel and the envelopment of model test results obtained in the two flow fields (e.g. the mean and fluctuating wind pressure distributions, the power spectral density, the coherence function, and the correlation coefficient). The superiority of the new atmospheric boundary layer wind tunnel simulation methodology over the traditional model test practice is demonstrated by comparing the model test results with the full-scale measurement data.


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