Center for Fluid Mechanics Seminar: Jesse Belden, NUWC

About this event

Jesse Belden, Chief Scientist, Naval Undersea Warfare Cente r (NUWC), will present a talk, "Splash and cavity dynamics during high-speed water entry."Abstract: The pervasive sequence characterizing the water entry of rigid bodies impact, splash and cavity formation, cavity seal, and cavity collapse-is critically dependent on the interaction be tween the displacing liquid and the surrounding air. While recent work has elucidated the changing splash dynamics from low-speed splash dome-over (O(1 m/s)) to high-speed splash-root buckling (O(100 m/s)), predicting the precise dynamics of the seal remains a theoretical challenge. Building on high speed imaging and direct cavity pressure measurements, we have developed an analytical model for the evolution of the splash that explicitly predicts closure mechanics. Recognizing that the above-surface splash and sub-surface cavity are coupled and co-evolve, the splash formulation is directly coupled to an analytical model of the cavity shape and internal pressure. To accurately capture this interaction, our framework requires that we model the highly compressible gas flow accelerating into the cavity prior to the seal. By integrating the liquid hydrodynamics with the compressible aerodynamics, our model demonstrates that the cavity and splash are a highly coupled system. The compressible gas flow and resultant pressure variations within the cavity strongly influence the splash trajectory and closure time. Our predictions of splash shape and closure times compare favorably with experiments.Bio: Dr. Jesse Belden is the Chief Scientist for the Weapons, Vehicles and Defensive Systems Department (Code 85) of the Naval Undersea Warfare Center Division Newport and an Adjunct Professor at Brown University. Dr. Belden's research interests are in the areas of projectile water entry, fluid-structure interaction, multi-phase flow physics, and experimental methods for fluid flows. He received his Ph.D. in mechanical engineering from the Massachusetts Institute of Technology (MIT) in 2011. Since joining NUWC Newport, Dr. Belden has served as the principal investigator on numerous basic and applied research efforts. His contributions to the field of water entry have resulted in several peer-reviewed journal articles in top journals including Nature Communications, Physical Review Letters, Journal of Fluid Mechanics, and more. Dr. Belden's work has also garnered significant media coverage, including in Scientific American. Dr. Belden has received numerous awards, including the Assistant Secretary of the Navy (RDA) Dr. Delores M. Etter Top Emergent Scientist Investigator in 2018. dynamics during high-speed water entry."

Abstract:

The pervasive sequence characterizing the water entry of rigid bodies impact, splash and cavity formation, cavity seal, and cavity collapse is critically dependent on the interaction between the displacing liquid and the surrounding air. While recent work has elucidated the changing splash dynamics from low-speed splash dome-over (O(1 m/s)) to high-speed splash-root buckling (O(100 m/s)), predicting the precise dynamics of the seal remains a theoretical challenge. Building on high speed imaging and direct cavity pressure measurements, we have developed an analytical model for the evolution of the splash that explicitly predicts closure mechanics. Recognizing that the above-surface splash and sub-surface cavity are coupled and co-evolve, the splash formulation is directly coupled to an analytical model of the cavity shape and internal pressure. To accurately capture this interaction, our framework requires that we model the highly compressible gas flow accelerating into the cavity prior to the seal. By integrating the liquid hydrodynamics with the compressible aerodynamics, our model demonstrates that the cavity and splash are a highly coupled system. The compressible gas flow and resultant pressure variations within the cavity strongly influence the splash trajectory and closure time. Our predictions of splash shape and closure times compare favorably with experiments.

Bio:

Dr. Jesse Belden is the Chief Scientist for the Weapons, Vehicles and Defensive Systems Department (Code 85) of the Naval Undersea Warfare Center Division Newport and an Adjunct Professor at Brown University. Dr. Belden's research interests are in the areas of projectile water entry, fluid-structure interaction, multi-phase flow physics, and experimental methods for fluid flows. He received his Ph.D. in mechanical engineering from the Massachusetts Institute of Technology (MIT) in 2011. Since joining NUWC Newport, Dr. Belden has served as the principal investigator on numerous basic and applied research efforts. His contributions to the field of water entry have resulted in several peer-reviewed journal articles in top journals including Nature Communications, Physical Review Letters, Journal of Fluid Mechanics, and more. Dr. Belden's work has also garnered significant media coverage, including in Scientific American. Dr. Belden has received numerous awards, including the Assistant Secretary of the Navy (RDA) Dr. Delores M. Etter Top Emergent Scientist Investigator in 2018.