[No title available]

Measurements on square rods with their square face normal to turbulent flow show that the mean base pressure can be varied considerably with turbulent intensity and scale as well as with the thickness of a rod. Turbulence decreases the mean base pressure of a short rod while it increases the mean base pressure of a long rod. Turbulence causes earlier reattachment of the separated shear layers to the sides of a long rod. It is suggested that the effect of turbulence on the mean base pressure of a rod is restricted to a certain finite range of turbulence scale. There is a subrange of turbulence scale where the mean base pressure, although very different from the smooth-flow value, remains almost unchanged with turbulence scale. Paper presented at 5th Colloquium on Industrial Aerodynamics, Building Aerodynamics, (Aachen, Fed. Rep. Germany: Jun. 14-16, 1982). (A)