On the Reynolds number sensitivity of the aerodynamics of bluff bodies with sharp edges

A review of recent comparisons between the aerodynamic characteristics of bluff bodies with sharp edges at low and high Reynolds number is presented. It is concluded that the relaxation of the Reynolds number similitude requirement in the study of the aerodynamics of bluff body such as long span bridge decks can lead to systematic errors. It is observed also that some bluff geometries appear to be more sensitive than others to Reynolds number effects. Parameters that could link the geometry of a bluff body with the sensitivity of its aerodynamics to Reynolds number have to be clearly defined. An ongoing study of these issues based on experiments in a pressurized wind tunnel at the National Research Council Canada is introduced and preliminary results are discussed. For rectangular prisms, the fineness ratio or width-to-depth ratio is identified as one of the parameters.