Dye visualization of the wake produced with the panel of AR = 1.11, A = 2 cm (A/S = 0.15) at a St = 0.13 (the optimal Strouhal number for this configuration: η = 0.18), ReC = 36,000, and b St = 0.33, ReC = 13,500. At the lower Strouhal number, the near wake represents a reverse Kármán vortex street, whereas at the higher Strouhal number, the wake rapidly bifurcates