Abstract: The effect of the size of a delta wing relative to that of the test section on the vortex breakdown location over a delta wing oscillating in pitch to very high angles of attack was investigated experimentally using flow visualization in wind tunnel in NUAA. The models tested consist of two sets of delta wings having 65° and 70° leading edge sweep.The wings in each set differ from one another in their linear dimensions. The breakdown location, at the same constant angle of attack,moves continuously backward as the wing grows larger.

Key words: unsteady flo, vortex breakdown interference, wind tunnel walls