Aerodynamic effects of probe-induced flow separation of bluff bodiesat transonic Mach numbers

Transonic flow modes of an axisymmetric blunt body

“…Previous studies of qualitatively similar flows have suggested that C D reaches a minimum value at a probe length slightly less than critical. 3 Guided by this, the critical length for the probe/cylinder might be approximated by the probe length midway between the minimum and plateau for subsonic flow and by the probe length at which the drag suddenly increases for supersonic flow. The length so determined appears in Fig.…”

“…For relatively short probes, there is a single separated zone between the probe face and the cylinder face, whereas longer probes produce two separated zones in this region. 3 These two situations correspond to the open and closed modes, respectively, of a cavity or cutout in a wall 4 (see the inset of Fig. 3).…”