Cavitation & Bubbles: Investigation of the Physical Mechanisms by Joint Experimental and Numerical Approaches

Date: 
Friday, February 16, 2018 - 2:30pm
Location: 
3110 Etcheverry Hall
Speaker: 
Olivier Coutier-Delgosha

Associate Professor

Virginia Tech

About: 

E-201 Ocean Engineering Seminar Series, Spring 2018

 

2:00 - 2:30pm Beverages & Refreshments

2:30 - 4:00pm Seminar

 

Hydrodynamic cavitation is the partial vaporization of high speed liquid flows. The turbulent, compressible and unsteady character of these flows makes their study unusually complex and challenging. Both fundamental mechanisms and effects of cavitation in rotating machinery (mainly rocket engine turbopump inducers) have been investigated in the last 15 years at Arts et Metiers ParisTech by joint experimental and numerical approaches. The most recent activities have been focused on the use of X-ray imaging to obtain time resolved high resolution fields of void fraction and velocities in both phases. The primary objective is to characterize the two-phase flow structure, the large-scale instabilities and the properties of turbulence. In parallel, a CFD approach based on homogeneous cavitation modelling has been continuously conducted, to improve the cavitation and turbulence models. Validation of the results and new challenges like DNS and RANS optimization based on Machine Learning are now made possible thanks to the database provided by the experimental X-ray work. Other current projects dealing with cavitation erosion, characterization of thermal effects associated with expansion and collapse of bubbles, and DNS of oil/water flows will be also briefly evocated.

Biography: 

Olivier Coutier-Delgosha is currently Associate Professor at Virginia Tech, in the Kevin K. Crofton Department of Ocean and Aerospace Engineering. He recently moved from France, where he was full professor in Arts et Metiers ParisTech, one of the French Grandes Ecoles for future engineers, and the director of the CNRS LML laboratory in Lille. His research activity is in the area of hydrodynamics and has especially focused for the last 20 years on two-phase flows. Study of cavitation, which involves the coexistence of liquid and vapor phases in high speed flows, has been his main research interest. The turbulent, compressible and unsteady character of these flows makes their study unusually complex and challenging. Both fundamental mechanisms and effects of cavitation in rotating machinery have been investigated by joint experimental and numerical approaches. This work has resulted in significant technical contributions, in particular to a better understanding of the morphology and dynamics of cavitating flows.

 

Hosted by: Asst. Prof. S.A. Mäkiharju, 6179 Etcheverry Hall (makiharju@berkeley.edu