Periodic vortex shedding over delta wings

again the edges were nearly parallel, and except for the formation of cells, the wakes organized themselves in a nearly twodimensional fashion. In the problem under discussion here, the edges form an angle of 30 deg, and moreover they are inclined with respect to the flow. Preliminary findings on this problem were published by the present authors in a short Note.18 The variation of the Strouhal number vs the angle of attack and the Reynolds number was partially investigated. The main thrust in the present effort is to explore the flowfield for organized natural oscillations and to identify their character. The existence of two different shedding modes (simultaneous and alternate) is now documented in terms of pairs of hot-wire signals. The angle-of-attack ranges in which each models present are investigated for the entire domain of shedding angles of attack (35 < a < 90 deg). The orientation of the shed vortices with respect to the wing and their evolution in time are studied. Finally, flow visualization techniques are used to support the earlier findings.