An assessment of the universal Strouhal number concepts for two-dimensional bluff bodies

Summary The ‘universal’ Strouhal number, SB, which was derived by Bearman using the Kronauer vortex stability criterion is presented for two-dimensional rectangular-section prisms of depth to width ratio, d/h, from 1 to 5, for a flat plate with and without splitter plates, for a circular cylinder with splitter plates and for a circular cylinder with two blowing slots to control its wake width. A value of SB close to Bearman's value of 0·181 is obtained for the prisms of small d/h, for the plate without a splitter plate, for the cylinder with small splitter plates and for the cylinder for low blowing rates. For the other cases, however, SB is found to vary within the range 0·137 to 0·208 which is an indication that the general application of this concept to two-dimensional bluff bodies is superficial.