Interference effects of three consecutive wall-mounted cubes placed in deep turbulent boundary layer

In this study we undertook various calculations of the turbulent flow around a building in close proximity to neighbouring obstacles, with the aim of gaining an understanding of the velocity and the surface-pressure variations with respect to the azimuth angle of wind direction and the gap distance between the obstacles. This paper presents the effects of flow interference among consecutive cubes for azimuth angles of $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\theta = 0$, 15, 30, and $45^{\circ }$ and gap distances of $G = 0.5{h}, 1.0{h}, 1.5{h}$, and $\infty $ (i.e. a single cube), where $h$ is the cube height, placed in a turbulent boundary layer. A transient detached eddy simulation (DES) was carried out to calculate the highly complicated flow domain around the three wall-mounted cubes to observe the fluctuating pressure, which substantially contributes to the suction pressure when there is separation and reattachment around the leading and trailing edges of the cubes. In addition, the results indicate that an increasing azimuth angle increases the pressure variation on the centre cube of the three parallel-aligned cubes. The mean pressure variation can even change from negative to positive on the side face. Owing to interference effects, the mean pressure coefficient of the centre cube of the three parallel-aligned cubes was generally lower than the coefficient of the single cube and tended to increase depending on the gap distance. Furthermore, when the three consecutive cubes are in a tandem arrangement, the gap distance has little influence on the first cube but results in significant interference effects on the second and third cubes.