Wind flow characteristics and Reynolds stress structure around the two-dimensional embankment of trapezoidal shape with different slope gradients

In this study, wind tunnel measurements for a turbulent boundary layer flow over two-dimensional embankments of trapezoidal shape with different slope gradients were carried out to investigate the wind flow characteristics and the Reynolds stress structure. The quadrant analysis technique was employed to analyze stress component contribution to the Reynolds stress. Measurement on the Reynolds stress structure reveals that both the sweep and ejection events are the major contributors to the Reynolds stress for flow around the embankment with different slope gradients. The contributions to the Reynolds stress made by sweep event are slightly larger than that of ejection event at locations close to the top surface of embankment (Z/H=1.2) with mild slope (slope gradient 4:1). But at higher distance from the top surface of the embankment (Z/H=2), the ejection event contributes more to the Reynolds stress than the sweep event for all cases (slope gradients, 1:1, 2:1, 4:1).