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Aerospace Engineering Commons

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Full-Text Articles in Aerospace Engineering

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi Dec 2022

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an effort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …


Polyelectrolyte Functionalized Forward Osmosis For Water Reclamation From Synthetic Spacecraft Wastewater, Alina Ripp Dec 2022

Polyelectrolyte Functionalized Forward Osmosis For Water Reclamation From Synthetic Spacecraft Wastewater, Alina Ripp

Electronic Theses and Dissertations, 2020-

This study investigated the application of a polyelectrolyte (PE)-assisted metallic iron nanoparticle-integrated forward osmosis (FO) membrane to treat synthetic spacecraft wastewater comprising urea, ammonium carbonate, and linear alkylbenzene sulfonate (LAS). The draw solution (MgSO4) diluted via the FO operation was further treated using a nanofiltration (NF) membrane aimed at producing potable quality water by the FO-NF hybrid process. A cellulose triacetate FO membrane was functionalized by layer-by-layer deposition of polyallylamine hydrochloride (PAH) and polyacrylic acid (PAA) followed by incorporating zero valent iron nanoparticles (ZVINP) within the "bilayers". It required 14 bilayers to ensure a uniform coating as demonstrated via scanning …


Understanding Unsteady Corner Separation Within Wing-Body Junction Flows, Paul G. Winner Oct 2022

Understanding Unsteady Corner Separation Within Wing-Body Junction Flows, Paul G. Winner

Doctoral Dissertations and Master's Theses

Wing-body junction flows, formed at the interface between a wing and fuselage surface, are a complex, coupled, three-dimensional, turbulent flow field. This thesis focused on the unsteady corner separation that develops at the trailing edge of this wing-body junction under certain conditions. A NACA 0015 wing mounted on a flat plate at an angle of attack of 13°was used as the model junction flow field. The wing had an aspect ratio of 8 with a linear washout twist of 15°. The Reynolds number based on the wing chord was Rec = 4.5 × 105. Time-dependent stereoscopic particle …


A Computational Fluid Dynamics-Based Surrogate Wind Turbine Blade Aerodynamic Model For Hybrid Simulation, Eric Lalonde Feb 2022

A Computational Fluid Dynamics-Based Surrogate Wind Turbine Blade Aerodynamic Model For Hybrid Simulation, Eric Lalonde

Electronic Thesis and Dissertation Repository

Hybrid simulation (HS) is a promising technique for studying wind turbines due to the presence of scaling errors in wind tunnel testing. However, HS of wind-loaded structures is limited by the current practice of using lower-accuracy, "pre-calculated" aerodynamic loads, which uncouple the aerodynamic loading from the structural response. This thesis presents six stand-alone studies that collectively build towards a novel HS framework that employs a computational fluid dynamics (CFD) based surrogate model to generate higher-accuracy aerodynamic loads within the HS loop. An experimentally-validated residential wind turbine model equipped with an external damping system was used to illustrate the proposed framework. …