Measurements of the gas and particle flow within a converging-diverging nozzle for high speed powdered vaccine and drug delivery

A unique system has been developed based upon the concept of accelerating pharmaceutical agents in particle form with a gas flow to attain sufficient momentum to enter the epidermis of human skin and achieve a pharmacological endpoint. This paper presents an experimental investigation of the transient gas and particle dynamics within a transonic converging-diverging nozzle prototype. The primary gas flow regimes are identified through Pitot-static pressure surveys and schlieren images with a high frame rate. The action of the gas flow-field in imparting momentum to the drug particles is investigated through schlieren imaging and time-resolved Doppler global velocimetry (DGV).