Velocity scales for constrained flows

Abstract

Two-dimensional flow past a bluff body can be constrained under two important circumstances. For single models, the side walls of a testing facility can impose a constraint on the flow past the model. On the other hand, for single row configurations the adjacent members impose a constraint on the flow past an intermediate member of the row. Both these effects are a consequence of boundary interference.Ealier investigations related to the interference effects of side walls on the vortex shedding frequency and drag coefficient of single bluff bodies were limited to weakly constrained flows. Recently, side wall interference effects have been reported for severely constrained two-dimensional flows past normal plates, inclined plates, triangular prisms and circular cylinders Constraint or blockage for two-dimensional flow is defined as the ratio of the model width to the test section width. While defining blockage for single rows of bodies, the width of the test section has to be replaced by the spacing between adjacent rows of bodies.