ME Assistant Professor Eric Johnsen has been selected by Oak Ridge Associated Universities (ORAU) to receive a 2010 Ralph E. Powe Junior Faculty Enhancement Award. These awards provide a one-year grant to fund research by junior faculty at ORAU member institutions with the aim to enrich the research and professional growth of young faculty.
Johnsen’s proposed research will investigate the dynamics of cavitation bubbles and shock waves as they occur in the operation of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, which generates the most intense pulsed neutron beams in the world. The intense heating of the mercury target by a proton beam during the operation of SNS creates large changes in pressure which lead to the formation of cavitation bubbles. The violent collapse of these bubbles and the subsequent emission of shock and acoustic waves have been shown to generate damage on the container walls and thus have the potential to reduce its lifetime.
Johnsen plans to develop a numerical model and carry out large-scale numerical simulations to better understand this occurrence, to assess the cavitation damage, and to investigate mitigation strategies based on the fluid and solid dynamics calculations.
Johnsen directs the Computational Flow Physics Laboratory.