ABSTRACT

Turbulent buoyant jets are a fundamental žow class in the naturalandengineeredenvironmentandspanthefullasymptotic rangeofjetandplumebehavior:roundjets,linejets,momentum pu§s,negativejets,roundplumes,lineplumes,andthermals. Insummary,buoyantjetsoccurwheneveržuidisdischarged withanexcessofordeŸcitinmomentumand/orbuoyancy throughaconstrictionintoareceivingžuidbody.›eyoccurin awholehostofapplications,andwewouldliketoquoteGerhard Jirkafromhis(2004)paperinthejournalEnvironmental Fluid Mechanics where he outlined his view of the topic:

Buoyant jet motions (sometimes called forced plumes) are prevalent in the natural environment and in engineering applications. ›ey are most spectacular in volcanic gas eruptions, they occur as hydrothermal vent žows in the deep ocean or as fresh groundwater plumes in the coastal zone. ›ey are a key feature in society’s žuid waste disposal methods, be it in the form of gaseous emissions into the atmosphere from industrial and domestic smokestacks, from mobile exhausts and from cooling towers, or of liquid releases into water bodies from industrial, municipal and agricultural sources or mining and oil extraction operations. ›ey are an integral part of building ventilation and air conditioning systems. And they play a central role as mixing and injection devices in chemical reactors, waste and sewage

treatment plants, desalination plants, combustion chambers, jet engines, or heat exchangers as well as stratiŸcation control and oxygenation devices in lakes or reservoirs.