Mechanical Engineering Graduate Seminar

Thursday, April 20 at 3:30 pm to 4:20 pm
Seamans Center, 3505 SC
103 South Capitol Street, Iowa City, Iowa

"Examination of partical Cavitation Dynamics Using  Cinemagraphic X-Ray Densitomety" presented by Prof. Steven Ceccio, ABS Professor of Marine & Offshore Design and Performance, Chair of Department of Naval Architecture & Marine Engineering, Mechanical Engineering, University of Michigan, Ann Arbor. Abstract: Using time resolved X-ray densitometry, time resolved 2-D void fraction flow fields for a variety of cavitating flows are examined.  Example results from the cavitating flows formed at the apex of a wedge, the flow over a hydrofoil are presented.  In these cavities are obtained to identify the mechanisms of transition from closed partial cavities to open cavities exhibiting periodic shedding of large gas pockets. From the void fraction field measurements, two distinct types of cavity shedding mechanisms are identified: shedding associated with a re-entrant jet in the cavity closure region that produces intermittent shedding of smaller scale cavities, and large scale, periodic cloud shedding caused by the formation of a condensation shock within the high void-fraction flow in the separated region of partial cavitation. A discussion of the observed occurrence and properties of the shock wave, and its role in causing periodic shedding is presented based on the one-dimensional model of shock propagation in bubbly mixtures and the relationship between the transition to strong shedding as a function of the Mach number of the bubbly flow in the cavity. Individuals with disabilities are encouraged to attend all University of Iowa sponsored events. If you have a disability that requires an accommodation in order to participate in this program, please call  the department  in advance, at 335-5939.

Contact Info: MIE Office, mie-engineering@uiowa.edu, 319.335.5939