Mechanical Engineering Commons^™

Viscoelastic Flow Through Contraction Geometries, Ashwin Karthik Sankaran

Masters Theses 1911 - February 2014

Contraction flow of viscoelastic fluids has been a benchmark problem in non-Newtonian fluid mechanics because it mimics flows occurring in a number of industrial applications. It is also of considerable interest to academia to gain fundamental understanding of factors that affect the evolution of vortices and a complete understanding of the dynamics for a simple polymeric fluid has not been achieved. In this two part study we investigate the effect of pre deformation of a Boger fluid in a contraction geometry and the flow of surfactants in a parallel contraction geometry.

Entry flow of a polymeric fluid results in the …

Semi-Active Damping For An Intelligent Adaptive Ankle Prosthesis, Andrew K. Lapre

Masters Theses 1911 - February 2014

Modern lower limb prostheses are devices that replace missing limbs, making it possible for lower limb amputees to walk again. Most commercially available prosthetic limbs lack intelligence and passive adaptive capabilities, and none available can adapt on a step by step basis. Often, amputees experience a loss of terrain adaptability as well as stability, leaving the amputee with a severely altered gait. This work is focused on the development of a semi-active damping system for use in intelligent terrain adaptive ankle prostheses. The system designed consists of an optimized hydraulic cylinder with an electronic servo valve which throttles the hydraulic …

Effect Of Slip On Flow Past Superhydrophobic Cylinders, Pranesh Muralidhar

Masters Theses 1911 - February 2014

Superhydrophobic surfaces are a class of surfaces that have a microscale roughness imposed on an already hydrophobic surface, akin to a lotus leaf. These surfaces have been shown to produce significant drag reduction for both laminar and turbulent flows of water through large and small-scale channels. The goal of this thesis was to explore how these surfaces alter the vortex shedding dynamics of a cylindrical body when coated on its surface, thus leading to an alteration in drag and lift on these surfaces. A cylindrical body was chosen as it is a very nice representative bluff body and sets the …

Physical Model Of The Feeding Strike Of The Mantis Shrimp, Suzanne M. Cox

Masters Theses 1911 - February 2014

A physical model was built to study the properties of the feeding strike of the mantis shrimp that are responsible for drag reduction and cavitation control. The model had three goals: 1) The model was to be outfitted with a method to collect kinematic, force and cavitation data. 2) The velocity and acceleration profile of the model were to be predicted with a mathematical model of the mechanism. 3) The model was to match as many drag and cavitation sensitive properties of the mantis shrimp strike as feasible and have a means to control the rest. The first iteration of …