Dissertation/Thesis Abstract

Partially Rotating Stepped Cylinder and Pulmonary Arterial Hypertension: External and Internal Flow CFD Investigations
by Shin, Jamie, M.S., California State University, Long Beach, 2019, 59; 13860299
Abstract (Summary)

This thesis is divided into two parts to demonstrate cases of external and internal flow using computational fluid dynamics. In the first part, unsteady numerical analysis using the k-ω turbulence model was performed on a partially rotating stepped cylinder 2 meters in length with a 2:1 stepdown diameter rotating at 2000 or 4000 RPM. The objective was to investigate if partial rotation (half cylinder stationary, other half rotational) would impact wake characteristics. The free stream mean velocity was 10 m/sec, corresponding to a Reynolds number of 32,258 for the large cylinder rotational case. Velocity ratios studied included 0.25, 0.5, and 1.0 depending on rotational configuration. Results indicate that the large cylinder produced greater vortex generations and interactions downstream than the small rotating cylinder, indicating superior importance with aerodynamic efficiencies.

In part two of the investigation, computational fluid dynamics was used to investigate correlations between wall shear stress, pressure, and flow conditions for a patient with pulmonary arterial hypertension. Two different outlet boundary conditions were applied: zero traction model using constant pressures, and a three-element Windkessel lumped parameter model representing compliance, impedance, and resistance of the vasculature. In silico results were confirmed with retroactively performed right heart catheterization pressure measurements and indicated better correlation using the Windkessel model.

Indexing (document details)
Advisor: Rahai, Hamid
Commitee: Taherian, Shahab, Hoang, Huy T.
School: California State University, Long Beach
Department: Mechanical and Aerospace Engineering
School Location: United States -- California
Source: MAI 81/1(E), Masters Abstracts International
Subjects: Mechanical engineering, Aerospace engineering, Biomedical engineering
Keywords: CFD, Computational fluid dynamics, Pulmonary arterial hypertension, Rotating cylinder, STAR-CCM, Windkessel
Publication Number: 13860299
ISBN: 9781085556767
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