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Full-Text Articles in Engineering
Flutter Stability Of Shrouded Turbomachinery Cascades With Nonlinear Frictional Damping, Alex Torkaman
Flutter Stability Of Shrouded Turbomachinery Cascades With Nonlinear Frictional Damping, Alex Torkaman
Electronic Theses and Dissertations
Prediction of flutter in shrouded turbomachinery cascades is difficult due to i) coupling of aerodynamic drivers and structural dynamics of the cascade through shrouds, and ii) presence of nonlinear dry friction damping as a result of relative motion between adjacent shrouds. An analytical framework is developed in this dissertation to determine flutter stability of shrouded cascades with consideration of friction damping. This framework is an extension to the well-established energy method, and it includes all contributing factors affecting stability of the cascade such as aerodynamic excitation and the stabilizing effects of dry friction damping caused by nonlinear contact forces between …
Biomechanical Models Of Human Upper And Tracheal Airway Functionality, Don Nadun Kuruppumullage
Biomechanical Models Of Human Upper And Tracheal Airway Functionality, Don Nadun Kuruppumullage
Electronic Theses and Dissertations
The respiratory tract, in other words, the airway, is the primary airflow path for several physiological activities such as coughing, breathing, and sneezing. Diseases can impact airway functionality through various means including cancer of the head and neck, Neurological disorders such as Parkinson's disease, and sleep disorders and all of which are considered in this study. In this dissertation, numerical modeling techniques were used to simulate three distinct airway diseases: a weak cough leading to aspiration, upper airway patency in obstructive sleep apnea, and tongue cancer in swallow disorders. The work described in this dissertation, therefore, divided into three biomechanical …