Comparison of wind tunnel pressure measurements on the Texas Tech building
Chowdary, Niaz A
MetadataShow full item record
A recent trend has been observed concerning the mean extreme local pressure coefficients measured in wind tunnels and in full-scale experiments for flow around low buildings. It was observed that the magnitudes of the mean extreme pressure coefficients measured in wind tunnel studies have been increasing as the data acquisition methods and boundary simulation techniques have improved. Wind tunnel'test data on generic low building is being generated at the Boundary Layer Wind Tunnel Laboratory at the Texas Tech University to contribute to a large database that will be made available to designers. In the most recent of these experiments, two scaled models 1:100 and 1:50 of the Texas Tech University test building were investigated at two simulations in open terrain condition. Pressure data collected at several taps is analyzed for a large number of records roughly covering all angles of attack. The primary purpose of this thesis is to develop two simulations of the 10th and 90' percentile velocity and turbulence characteristics observed at WERFL and to compare point pressure coefficients between the three models, two simulations, and two other wind tunnel data sets (UWO & CSU). In addition, the study was extended to include comparisons of results obtained using the same model but tested in different wind tunnels (UWO & CSU). Tests were conducted for different wind simulations, and the data were used to develop a better understanding of the effect of flow simulation and model scale on wind load estimates for low-rise buildings. These were conducted in a boundary layer wind tunnel using simulations developed as part of a research program aimed at improving boundary layer simulations. The purpose of the improved simulations was to reduce the differences between wind tunnel data obtained at three different universities, two different scaled models and two different simulations, obtained from physical model studies in boundary layer wind tunnels. The comparison of the pressures measured on the 1:100 scale model at the Texas Tech University to those measured at two other institutions revealed that there are some differences. These differences appear to be due primarily to differences in the reference static and dynamic pressures used at the various institutions as indicated by the fact that the shape of the distribution of the pressures over the exterior of the building is maintained between the results from the various studies. Additional differences can be associated with differences in the local turbulence intensities present in the various simulations. Results indicate that without careful adjustments, the scale effects, and wind simulation variations can result in widely varying pressure coefficient predictions for the same structure. These discrepancies were attributed to the approach flow characteristics, Reynolds number effects, frequency response of the pressure measurement system, and sampling frequency of acquired data. The model and full-scale flow parameters and pressure coefficients are presented for low-turbulence nominal flow. The comparison of the model exhibits a better agreement for most of the pressure taps, including the critical corner region, than other reported wind tunnel results.