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Aerospace Engineering Commons

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Electronic Theses and Dissertations, 2020-2023

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Articles 61 - 66 of 66

Full-Text Articles in Aerospace Engineering

Viscoelastic Analysis Of High Strain Composites For Deployable Structures In Space Applications, Andrew Gomez-Delrio Jan 2020

Viscoelastic Analysis Of High Strain Composites For Deployable Structures In Space Applications, Andrew Gomez-Delrio

Electronic Theses and Dissertations, 2020-2023

Thin-ply composite laminates capable of enduring high strains are currently under investigation for compliant deployable spacecraft structures. Deployable structures such as booms fabricated from these materials can be flattened and coiled to high curvatures, achieving a compact configuration for stowage. Once in orbit, they are released with minimal actuation for deployment, allowing the operational geometry to be recovered. Previous studies have shown that the viscoelastic properties of the composite epoxy matrix can negatively impact final shape accuracy due to stress relaxation during stowage. In addition, since the strain energy stored is relied upon for deployment, considerable relaxation can potentially result …


Evaluation Of Convective Heat Transfer Numerical Methods On Rough Surfaces From Additive Manufacturing, Jose Urcia Jan 2020

Evaluation Of Convective Heat Transfer Numerical Methods On Rough Surfaces From Additive Manufacturing, Jose Urcia

Electronic Theses and Dissertations, 2020-2023

The high versatility of additive manufacturing has led to an increase in use in a number of different fields. Surface roughness then comes as a natural consequence of additive manufacturing which interferes with a smooth wall assumption such as those found in gas turbine blades. The Discrete Element Roughness Method (DERM) has been used to improve convective heat transfer predictions on surface roughness. This work aims to validate the core momentum and heat transfer correlation of DERM through an evaluation of Computational fluid dynamics (CFD)-based solution of the flow around individual roughness elements with the goal of improving the correlations. …


Rapid Orbital Motion Emulator (Rome): Kinematics Modeling And Control, Ahmed Elsadek Ahmed Seleit Jan 2020

Rapid Orbital Motion Emulator (Rome): Kinematics Modeling And Control, Ahmed Elsadek Ahmed Seleit

Electronic Theses and Dissertations, 2020-2023

Space missions design requires already tested and trusted control algorithms for spacecraft motion. Rapidly testing control algorithms at a low cost is essential. A novel robotic system that emulates orbital motion in a laboratory environment is presented. The system is composed of a six degree of freedom robotic manipulator fixed on top of an omnidirectional ground vehicle accompanied with onboard computer and sensors. The integrated mobile manipulator is used as a testbed to emulate and realize orbital motion and control algorithms. The kinematic relations of the ground vehicle, robotic manipulator and the coupled kinematics are derived. The system is used …


Efforts In Numerical Modeling Of Undulating Propulsion, George Loubimov Jan 2020

Efforts In Numerical Modeling Of Undulating Propulsion, George Loubimov

Electronic Theses and Dissertations, 2020-2023

Naval propulsion is a critical component for every vessel, and it is the subject of this thesis, specifically bio-inspired propulsion. Numerical modeling is used as a tool to understand the relationship between mechanical undulation and the hydrodynamic response. Through three stages, the research presented here examines and refines tools for understanding fundamentals of undulating propulsion. Those three objectives are: to verify and validate the proposed numerical models against existing experiments, establishing a baseline of fidelity; to examine the causal linkage between fluid-boundary interactions and undulating propulsion; and to create a moment based method for characterizing generalized undulating propulsive mechanisms. First, …


Study Of Non-Ideal Effects On Shock Wave Propagation, Cory Kinney Jan 2020

Study Of Non-Ideal Effects On Shock Wave Propagation, Cory Kinney

Electronic Theses and Dissertations, 2020-2023

Shock tube experiments provide insightful data on combustion, emissions, and ablation characterization for a wide variety of defense and energy sector research topics. Accurate characterization of shock tube facilities is essential to verifying the accuracy of research data. Non-ideal effects, such as boundary layer growth, introduce uncertainty into pressure and temperature conditions, the primary independent variables of interest for shock tube research results. The effect of boundary layer growth on shock tube experiments was investigated by conducting simulations for University of Central Florida's two geometrically different shock tube using StanShock, a quasi-one-dimensional, reacting, compressible flow solver. The characteristic quantities considered …


Hybrid Physics-Informed Neural Networks For Dynamical Systems, Renato Giorgiani Do Nascimento Jan 2020

Hybrid Physics-Informed Neural Networks For Dynamical Systems, Renato Giorgiani Do Nascimento

Electronic Theses and Dissertations, 2020-2023

Ordinary differential equations can describe many dynamic systems. When physics is well understood, the time-dependent responses are easily obtained numerically. The particular numerical method used for integration depends on the application. Unfortunately, when physics is not fully understood, the discrepancies between predictions and observed responses can be large and unacceptable. In this thesis, we show how to directly implement integration of ordinary differential equations through recurrent neural networks using Python. We leveraged modern machine learning frameworks, such as TensorFlow and Keras. Besides offering basic models capabilities (such as multilayer perceptrons and recurrent neural networks) and optimization methods, these frameworks offer …