Introduction G LANCING shock-wave/turbulent-boundarylayer interaction, in which an oblique shock wave glances across a boundary layer along an adjacent wall (Fig. 1), constitutes one of the most important phenomena of three-dimensional interference. The primary separation line is one of the most easily discerned features of the interactionfootprintobtainableby surface  ow visualization.In the interaction induced by a sharp Ž n or a semicone, the separation line is usuallystraightexcept the “inceptionregion.”Hence once the angle of the separation line ( s : deŽ ned as the angle formed by the separation line and the incoming freestreamdirection) is speciŽ ed, one can grasp the extent of interaction region. Koide et al.1 previouslyproposedan empirical predictionmethod for theprimary separationanglescausedby a seriesof unsweptsharp Ž ns (USF) with attack angle® (Fig. 1a), semicones (SC), and sharp triangle Ž ns (STF) at zero ® (Figs. 1b and 1c). In the prediction, only the inviscid shock-wave characteristics such as shock angle and pressure rise across the shock were employed. (Inviscid means the imaginary condition that would exist if no boundary layer were presented on the wall.) In this Note, the prediction method is extended to include swept sharp Ž n (SSF) with ® (Fig. 1d) and STF with ®. Using the extended method, the separation angles can be predicted for almost all types of sharp shock generators with various angles of attack ®, sweep angles , half-apex angles " under a wide range of supersonicMach numbers.