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Aerospace Engineering Commons

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West Virginia University

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Articles 91 - 95 of 95

Full-Text Articles in Aerospace Engineering

Investigation Of Rope Formation In Gas–Solid Flows Through A 90° Pipe Bend Using High-Speed Video And Cfd Simulations, Sai S. Guda, Steven L. Rowan, Tao Yang Jan 2017

Investigation Of Rope Formation In Gas–Solid Flows Through A 90° Pipe Bend Using High-Speed Video And Cfd Simulations, Sai S. Guda, Steven L. Rowan, Tao Yang

Faculty & Staff Scholarship

A study of rope formation in gas–solid flows through abrupt turns has been conducted. Experiments in which high-speed video was recorded and analyzed for solid concentration profiles were compared to CFD simulations utilizing both RANS and large eddy simulation turbulence models. In both simulations and experiments, particle-laden flows of air and ground flaxseed, with solid loadings of 35, 42, and 51% were considered. The results of the study demonstrate that both RANS and large eddy simulation can accurately predict particle roping. Furthermore, simulations show that the roping phenomenon is strongly dependent upon selection of an appropriate value for the coefficient …


Nanoionics And Nanocatalysts: Conformal Mesoporous Surface Scaffold For Cathode Of Solid Oxide Fuel Cells, Yun Chen, Kirk Gerdes, Xueyan Song Jan 2016

Nanoionics And Nanocatalysts: Conformal Mesoporous Surface Scaffold For Cathode Of Solid Oxide Fuel Cells, Yun Chen, Kirk Gerdes, Xueyan Song

Faculty & Staff Scholarship

Nanoionics has become increasingly important in devices and systems related to energy conversion and storage. Nevertheless, nanoionics and nanostructured electrodes development has been challenging for solid oxide fuel cells (SOFCs) owing to many reasons including poor stability of the nanocrystals during fabrication of SOFCs at elevated temperatures. In this study, a conformal mesoporous ZrO2 nanoionic network was formed on the surface of La1−xSrxMnO3/yttria-stabilized zirconia (LSM/YSZ) cathode backbone using Atomic Layer Deposition (ALD) and thermal treatment. The surface layer nanoionic network possesses open mesopores for gas penetration, and features a high density of grain boundaries for enhanced ion-transport. The mesoporous nanoionic …


Control Design And Performance Analysis For Autonomous Formation Flight Experiments, Caleb M. Rice Jan 2014

Control Design And Performance Analysis For Autonomous Formation Flight Experiments, Caleb M. Rice

Graduate Theses, Dissertations, and Problem Reports (ETD)

Autonomous Formation Flight is a key approach for reducing greenhouse gas emissions and managing traffic in future high density airspace. Unmanned Aerial Vehicles (UAV’s) have made it possible for the physical demonstration and validation of autonomous formation flight concepts inexpensively and eliminates the flight risk to human pilots. This thesis discusses the design, implementation, and flight testing of three different formation flight control methods, Proportional Integral and Derivative (PID); Fuzzy Logic (FL); and NonLinear Dynamic Inversion (NLDI), and their respective performance behavior. Experimental results show achievable autonomous formation flight and performance quality with a pair of low-cost unmanned research fixed …


Fault-Tolerant Trajectory Tracking Of Unmanned Aerial Vehicles Using Immunity-Based Model Reference Adaptive Control, Brenton K. Wilburn Jan 2014

Fault-Tolerant Trajectory Tracking Of Unmanned Aerial Vehicles Using Immunity-Based Model Reference Adaptive Control, Brenton K. Wilburn

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation presents the design, development, and simulation testing of an adaptive trajectory tracking algorithm capable of compensating for various aircraft subsystem failures and upset conditions. A comprehensive adaptive control framework, here within referred to as the immune model reference adaptive control (IMRAC) algorithm, is developed by synergistically merging core concepts from the biologically- inspired artificial immune system (AIS) paradigm with more traditional optimal and adaptive control techniques. In particular, a model reference adaptive control (MRAC) algorithm is enhanced with the detection and learning capabilities of a novel, artificial neural network augmented AIS scheme. With the given modifications, the MRAC …


Analytical Solution To The Wave Equation With Discrete Pressure Sources: A Model For The Rijke Tube, Eduardo G. Perez Jan 2008

Analytical Solution To The Wave Equation With Discrete Pressure Sources: A Model For The Rijke Tube, Eduardo G. Perez

Graduate Theses, Dissertations, and Problem Reports (ETD)

Despite of having been studied for several decades the phenomena of combustion instabilities are not well understood. Pressure waves due to the combustion instabilities can become violent being detrimental for both the performance and combustor life. A good prediction of the pressure distribution inside the combustor is important in order to prevent theoccurrence of this phenomenon. In this work a technique for solving the wave equation with discrete sources (or sinks) using the Green's functions was developed. One and two-dimensional approaches for cylindrical and Cartesian coordinates withconstant speed of sound were solved. Also the case of one-dimensional axially varying temperature …