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