Correlative Analysis between Pressure Distributions and VortexPattern of DoubleDelta Wings at High Angles of Attack

The pressure distributions on two models of doubledelta wing were measured in the low speed wind tunnel in BUAA.They are 75°/45° and 75°/60° doubledelta wings with sharp or round outboard leadingedge.The analysis indicates that two peaks of the pressure distributions on some typical cross sections of the doubledelta wing characterize the double vortices while the one peak of those characterize the single or merged vortex patterns.The position of the vortex core can be marked by the location of the spanwise pressure peak.The vortex breakdown can be displayed by the decrease of the pressure peak and flat pressure distribution with increasing angle of attack.The outboard leadingedge of the doubledelta wing being blunted causes inboard and outboard vortices close each other and stronger interaction.The pressure distributions and vortex breakdown positions will be unsymmetric about the centreline of the wing due to a side slip.All of the unsymmetric vortex flow characteristics that can be found on the correlative pressure distributions.