A computational model to calculate the flow-induced pressure fluctuations on a bluff body

Pressure fluctuations on buildings cause vibrations in moderate winds and structural damage under severe winds. They also play an important role in determining the noise level inside buildings and automobiles. Therefore, knowledge on pressure fluctuations is desired for improved design of buildings and automobiles. This knowledge can be obtained by experimental studies or computational studies. In recent years, computational methods have become more popular because they are less expensive compared to the field and wind tunnel experiments in most cases and they predict the parameters of interest with comparable accuracy.

In the current study, a computational technique is developed based on Reynolds Averaged Navier Stokes modeling (RANS), to predict the pressure fluctuation on a bluff body placed in turbulent flows. This technique has three main components: prediction of mean flow quantities, synthetic generation of velocity fluctuations, and prediction of pressure fluctuations. The mean flow calculations are performed using the standard K-s model with Kato and Launder modification, the fluctuating velocity field is synthesized from a stochastic description of the three dimensional turbulent motion, and the fluctuating pressure field calculations are performed by solving the Poisson equation for pressure fluctuation.

Flow around the low-rise experimental building at Texas Tech and the flow around an automobile in the A-Pillar region are analyzed using the developed technique. Two different wind angles of attack are considered for flow around the low-rise experimental building and two different A-Pillar geometries are considered for flow around an automobile. Computational results obtained using the developed technique, show good agreement with the experimental results.