Published 12 issues per year
ISSN Print: 1044-5110
ISSN Online: 1936-2684
Indexed in
VISUALIZATION OF CAVITATING FLOW WITHIN A HIGH-ASPECT-RATIO SLOT INJECTOR
ABSTRACT
Cavitation inside the passages of an injector can result in decreased discharge characteristics. This paper describes a flow visualization study to characterize cavitation structures in the flow of methanol through a series of high aspect ratio slot orifice injectors of varying L/DH. Cavitation structures were observed to evolve through a series of regimes corresponding to increased pressure drop across the injector. Specifically, the cavitation region lengthens as pressure drop increases. The lengthening cavitation results in a decrease in discharge coefficient that follows a predictable pattern. As the cavitaton lengthens to occupy the length of the injector and hydraulic flip occurs, the discharge coefficient drops suddenly away from what is predicted. In the cavitating injector other flow structures are observed and described. Also, high speed videos are analyzed for frequency content through the cavitation region. Frequency content appears to be concentrated below 1 kHz, with the majority of content existing below 200 Hz.