Engineering Commons^™

Computer Modeling And Signal Analysis Of Cardiovascular Physiology, Henian Xia

Doctoral Dissertations

This dissertation aims to study cardiovascular physiology from the cellular level to the whole heart level to the body level using numerical approaches.

A mathematical model was developed to describe electromechanical interaction in the heart. The model integrates cardio-electrophysiology and cardiac mechanics through excitation-induced contraction and deformation-induced currents. A finite element based parallel simulation scheme was developed to investigate coupled electrical and mechanical functions. The developed model and numerical scheme were utilized to study cardiovascular dynamics at cellular, tissue and organ levels. The influence of ion channel blockade on cardiac alternans was investigated. It was found that the channel blocker …

Turbulent Gas Breakup Modeling And Acoustic Void-Fraction Determination Studies In Support Of Cavitation Damage Mitigation Of The Spallation Neutron Source Target Vessel, Stuart Alexander Walker

Doctoral Dissertations

Pressure pulses induced by proton beam deposition lead to cavitation and pitting erosion of the SNS target vessel; this damage limits the lifetime of the vessel. Dampening the pressure pulse by adding compressibility to the bulk mercury in the form of microbubbles is a promising technique for damage mitigation. The physics governing gas bubble breakup in turbulent flows is examined leading to mechanistic based scaling models for the gas breakup in a swirling jet type microbubble generator. These models are verified experimentally in an air/water system and compared to a legacy empirical model. Verifying the performance of a microbubble generator …