Aerodynamic Characteristics of Three-Dimensional Surface-Mounted Objects in Tandem Arrangement

Abstract

The present analysis undertakes the complex research program aimed at understanding the aerodynamic characteristics of two square surface mounted bluff bodies immersed in a boundary layer. The main attention has been put on the role of interference of the wake flow connected with a process of vortex shedding as a factor stimulating the aerodynamics loads. The analysis has been performed for the three-dimensional case of two in-line surface-mounted bluff bodies, arranged in tandem. The program of the study consists of parallel wind-tunnel experiments and numerical simulation performed with the use of phase-averaged form of k-ε turbulence model in RNG version which have shown overall changes in flow pictures observed for different values of objects “immersion” in boundary layer H/δ. The flow structure around surface-mounted obstacles depends on various factors: the oncoming boundary layer thickness δ related to the height of obstacles H, the oncoming flow turbulence, the non-dimensional distance ratio (S/D) and the height ratio of the two consecutive bodies. Conjugation of two research methods improved the efficiency of the conducted investigations. The most important finding of present research has confirmed that the interference of the flow structure around the system of rectangular objects and aerodynamic characteristic can be modified in promising ways through a change of their geometrical parameters. This article is the second part of a twopart series. The first part, “Aerodynamic Characteristics of Two-Dimensional Sharp-Edged Objects in Tandem Arrangement”, appeared in the Archives of Mechanics ([Gnatowska, 60: 475–490, 2008]).