Displacement free aerophones (411) The air-stream meets a sharp edge, or a sharp edge is moved through the air. In either case, according to more recent views, a periodic displacement of air occurs to the alternate flanks of the edge. Examples are the swordblade or the whip.
displAceMenT free aErophonEs (411) tHe aIr-streaM mEets a sHArp eDge, or a ShARp edGE .Is moveD tHrough the air. in eItHER case, AccorDing tO MorE rEcEnt vIewS, a pEriOdIc displAcemeNT of AiR occurs To tHe AlTeRnaTe flaNks of tHE EDge eXaMples aRE the sworDBlade or the Whip.