Electronic Thesis and Dissertation Repository


Master of Engineering Science


Civil and Environmental Engineering


Dr. Girma Bitsuamlak


The objective of this study is to investigate the interaction of a bluff body with a downburst flow. Numerical investigation of the flow field using CFD analysis was carried out for three different downburst sizes (h/d=1, 2, 4) under suitable boundary conditions subjected to constant jet velocity. The downburst-structure interaction study was conducted for two jet diameters (h/d=1 and 4) and two radial locations from the downburst center.

The results showed that the downburst size greatly dominates the intensity of the flow. The largest downburst resulted in the highest velocity magnitude near the ground and also covered a larger area radially and vertically compared to the smaller downburst. All surface pressure coefficients obtained from the cube placed directly below the downburst center were higher for the larger downburst. The cube placed at a radial distance was engulfed partially for the smaller and fully for the larger downburst, resulting in pressure distribution similar with synoptic flow case for the latter.