Simplified Wind Flow and Aerodynamic Response of Residential Homes: Laboratory and Computational Fluid Dynamics Simulations

Published

November 1, 2011

Author(s)

T.C. Fu, A.M. Aly, Arindam Chowdhury, Girma Bitsuamlak, DongHun Yeo, Emil Simiu

Abstract

The reliable measurement of pressures on low-rise buildings in the atmospheric boundary layer (ABL) flow remains a challenge, as has been shown by the large discrepancies among results obtained in different wind tunnel facilities or even in the same wind tunnel. Two major causes of the discrepancies are the difficulty of simulating low-frequency turbulent fluctuations uniformly across laboratories, and the small scale of models in typical civil engineering wind tunnels. To address these issues, it was proposed that a simplified flow be used in laboratory simulations, rather than a conventional ABL flow. In the simplified flow the reference mean wind speed is larger than the mean wind speed of the ABL flow, and the low-frequency fluctuations present in the ABL flow are suppressed; that is, the peak energy of the missing low-frequency fluctuations is supplied in the simplified flow by the increment in the mean wind speed, which may be regarded as a flow fluctuation with zero frequency. High-frequency turbulent fluctuations, which typically affect flow reattachment, are approximately the same in the ABL and the simplified flow. Since, over small distances, low-frequency fluctuations are highly coherent spatially, the peak aerodynamic effects of the two flows may be hypothesized to be approximately the same. Preliminary experimental results obtained in Florida International University's small-scale Wall of Wind facility are shown to support this hypothesis. The implications of our hypothesis for Computational Fluid Dynamics (CFD) simulations are briefly discussed. It is submitted that the detailed simulation of the turbulence in the oncoming ABL flow appears to be typically unnecessary for the testing of residential homes and other structures with relatively small dimensions. The use of simplified flows is advantageous from the points of view of model scaling, measurement accuracy, and repeatability of the testing; for CFD calculations it is advantageous from the standp

Proceedings Title

EVACES 2011 – Experimental Vibration Analysis for Civil Engineering Structures

Conference Dates

October 3-5, 2011

Conference Location

Varenna, IT

Pub Type

Conferences

Keywords

Atmospheric boundary layer wind, wind tunnel, Compufational Fluid Dynamics, simplified wind model

Citation

Fu, T. , Aly, A. , Chowdhury, A. , Bitsuamlak, G. , Yeo, D. and Simiu, E. (2011), Simplified Wind Flow and Aerodynamic Response of Residential Homes: Laboratory and Computational Fluid Dynamics Simulations, EVACES 2011 – Experimental Vibration Analysis for Civil Engineering Structures, Varenna, IT (Accessed May 3, 2024)