In the present technical note, the drag characteristics of two-dimensional wall-mounted circular cylinders and equiangular prisms (wall bodies) are reported. Comparison of drag data .for model mounting with and without end gaps are made at identical blockage ratios. Visual observation,s indicate that the lower forebody pressure for wall body model is caused by appreciable defection of the flow approaching this model. For models with finite end gaps this flow deflection is not excessit'e at comparable blockage. This causes the drag force to be lower figr wall bodies. When the wall body is in the,figrm of a circular o'linder, Reynolds number eff'ects shouM be consMered besides blockage.
b B b/B ~L'B CD d e/b e'd G G/b G.'d L R U ltr P P NOMENCLATURE Widtb of triangular prisms (figure I t Width of test section (figure 1) Blockage (two-dimensional flows) Drag coefficient (= Steady Drag/(I/2 pUZbL)) Pressure coefficient Diameter of circular cylinders Distance between the centre line of the test body and that of the wind tunnel (figure l/ Eccentricity Distance between the test body and the side wall of the wind tunnel (narrow side) (figure I I Gap width Span of the body Reynolds number based upon b or d (= uh/v, or udq') Mean undisturbed velocity (figure 1) Shear velocity Kinematic viscosity of fluid Density of fluid