Effect of interference on the pressure distribution on the ground plane around two low-rise prismatic bodies in tandem arrangement

In this paper the pressure distribution on the ground plane along the centre line of prismatic bodies with square cross section and height to width (h/b) ratio of 1 and 3 are presented when the bodies are in tandem arrangement. The dimensions used are typical of low-rise buildings. For bodies with h/b=1, the results indicate that when the gap between the bodies is small, it is the front body which influences the gap pressures. But for bodies with h/b=3, even at small gaps both the front and rear bodies influence the gap pressure distribution. An increase in the base pressure of the rear body compared to the no-interference case is observed. The interference effects are in general, stronger for the body with h/b=3 than for h/b=1. Flow visualisation results are presented which reveal the changes in the flow patterns that occur with interference. There is good correspondence between the pressure distribution results and the flow visualisation studies. The results presented are applicable to low-rise building aerodynamic problems with some limitations.Nomenclature b width of the body - C_pw (p–p_r)/1/2U_r², pressure coefficient on the ground - g gap between the bodies in tandem arrangement - h height of the body - I length of the body along the flow direction - p pressure at any point on the surface plate with the body - p_r pressure at the same point on the surface plate without the body - s distance from the leading edge of the surface plate to the front face of the body - U local velocity at a distance y from the ground - U_r free stream reference velocity - x coordinate along the flow direction - x coordinate along the centre line measured from the front face of the rear body - y vertical distance from the ground - density of air