LINEAR-STABILITY OF 3-DIMENSIONAL BOUNDARY-LAYERS OVER AXISYMMETRICAL BODIES AT INCIDENCE

The linear stability of the fully three-dimensional boundary layer formed over a 6:1 prolate spheroid at 10-deg incidence is investigated using a modified version of the linear stability code COSAL. For this case, both Tollmien-Schlichting and crossflow disturbances are relevant in the transition process. The predicted location of the onset of transition using the e(N) method compares favorably with experimental results of Meier and Kreplin. Using a value of N = 10, the predicted location is located approximately 10% upstream of the experimentally determined location. Results also indicate that the direction of disturbance propagation is dependent on the type of disturbance and, hence, the dimensional frequency. We also investigate characteristics of the most amplified disturbances at various streamwise locations.