Transparent high-pressure nozzles for visualization of nozzle internal and external flow phenomena

A new design for transparent high-pressure nozzles is presented in this work. This new design enables using the innovative Selective Laser Etching (SLE) method to manufacture transparent nozzles with outstanding accuracy. Therefore, not only the simultaneous visualization of the flow mechanics inside and outside the nozzle is enabled, but the manufacturing method applied also allows for the realization of individual nozzle geometries. Thus, nozzle internal flow phenomena (e.g., cavitation, swirl, and air inlet) and their influence on primary breakup can be analyzed with realistic nozzle geometries, e.g., for automotive applications. In addition, targeted three dimensional nozzle geometric parameters can be designed and manufactured in order to get specific tailor-made spray characteristics (e.g., droplet size distribution, spray angle, and penetration length). The basis for the transparent nozzle design is a two-parted nozzle, consisting of a re-machined original serial nozzle body and a transparent nozzl...