Numerical investigation of supersonic flows around a spiked blunt body

Drag Reduction Using Aerodisks for Hypersonic Hemispherical Bodies

“…The drag reduction experienced by spiked blunt bodies was explained by the size of the recirculation zone, which screens a considerable portion of the main body [1,3,12]. Increasing the spike length causes the reattachment point to move further downstream along the main body surface and the recirculation zone to expand, covering a larger area of the main body; consequently, a further drag drop is achieved.…”

“…Hence, the blunt body is replaced by an effective conical body drawn by the shear layer. Yamauchi et al [12] explicitly used the "effective body" term to refer to the shape of the shear layer.…”

“…However, Crawford [11] indicated signs of foreshock "waviness" in his experiments. Later, in their numerical reproduction of Crawford's experiments, Yamauchi et al [12] and Mehta [14] reported flow instabilities. Yamauchi et al [12] recorded a periodic variation of the drag coefficient, which was claimed to be caused by the unsteady vortices inside the recirculation zone.…”

“…Later, in their numerical reproduction of Crawford's experiments, Yamauchi et al [12] and Mehta [14] reported flow instabilities. Yamauchi et al [12] recorded a periodic variation of the drag coefficient, which was claimed to be caused by the unsteady vortices inside the recirculation zone. On the other hand, Mehta [14] recorded periodic pressure variation on both spike and body surfaces, which was argued to indicate self-sustained flow oscillations.…”

“…All models were equipped with pointed spikes with lengths ranging up to L=D 4. The experimental investigation by Crawford was reproduced numerically by a number of researchers, for example, Yamauchi et al [12], Mehta [13,14], and Asif et al [15]. Holden [5] measured the heat transfer to spiked hemisphere cylindrical models in turbulent hypersonic (M 1 10, 15) flow conditions.…”