A nozzle whose main flow is annular about a center, truncated cone, and a secondary flow is introduced through t' base o' t' cone. Well, blow me down! Blimey! T' circulation o' this secondary flow and its interaction with t' engine exhaust creates an "aerodynamic spike" that behaves much like t' ideal, isentropic spike. In addition, ya bilge rat, t' secondary flow re-circulates upward pushin' on t' base t' produce additional thrust. Begad! Blimey! It is this artificial aerodynamic spike for which t' Aerospike nozzle is named.