Aerospace Engineering Commons^™

Computational Analysis Of High Carbon Steel For Optimal Design, Muhammad Zubair, Aneela Wakeel, M. Mustafa Azeem, Aneeqa Tabbassum

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To increase the reliability of materials the computational analysis has been considered a vital tool for designing the components in the mechanical and nuclear engineering. By increasing a high percentage of carbon in liquid steel subsequently enhance the hardness, elasticity and toughness of the materials. In this research high carbon steel has been used due to its wear resistance properties in order to increasing hardness and strength. The findings of this research reveal the high carbon steel a good replacement material for conventional iron due to its low weight. Modeling and analysis of the steel, metallic glass and high carbon …

Novel Piezo Actuators For Surface Cleaning, Yezad H. Anklesaria

Doctoral Dissertations

"Optical cameras are becoming increasingly common and are used in a variety of applications. With recent progress and transition toward more autonomous systems, the usage of optical systems will be common and widespread. Applications of the optical systems range from autonomous vehicles, home security systems, aviation, extraterrestrial vehicles, spacecraft, and satellites. Imaging systems are used in decision-making in many of these applications. Fouling of the field of view of the imaging system can impede the decision process. An active autonomous cleaning method for the optical surface of the optical systems reliably would be advantageous. The research work focuses on developing …

Dynamic Behavior And Interactions Of Ferrofluid Droplets Under Magnetic Fields In Low Reynolds Number Flows, Md Rifat Hassan

Doctoral Dissertations

Digital microfluidics in combination with emulsion microfluidics are crucial building blocks of droplet-based microfluidics, which are prevalent in a wide variety of industrial and biomedical applications, including polymer processing, food production, drug delivery, inkjet printing, and cell-based assays. Therefore, understanding the dynamics and interactions of droplets as well as the interactions between the droplets and solid surfaces are of great importance in order to improve the performance or product in these applications.

Recently, several studies in the literature have demonstrated the potential of magnetic fields in controlling the behavior of droplets in microscale; however, the fundamental mechanism behind the interesting …

Composite-Based Additive Manufacturing Applications In The Polymer Injection Molding Cycle, Cody Bivens

Masters Theses

“The experimental method utilized in this research was the application of composite-based additive manufacturing (CBAM) mold plates in the injection molding process. The mold plates comprised carbon fibers and polyether ether ketone (PEEK) matrix. Modifications were made to the mold plates post manufacturing in order to properly adapt to the rest of the injection molding die. A custom cooling system was engineered and integrated into the injection molding machine for the CBAM mold plates. The polymer processed in the injection molding cycle for this study was Lustran 348 acrylonitrile butadiene styrene (ABS). The result of the trials conducted in this …

Aerothermal Uncertainty Quantification Of Deployable Entry Technologies Using Multi-Fidelity Modeling, Mario Santos, Serhat Hosder, Thomas K. West

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The objective of this work was to investigate the use of a co-Kriging based multi-fidelity modeling approach with a Monte Carlo uncertainty quantification analyses of surface heating on hypersonic inflatable aerodynamic decelerator vehicles and adaptable, deployable entry placement technology vehicles in Mars entry. A previously developed co-Kriging based multi-fidelity modeling approach was used to model the laminar and turbulent convective and radiative heat fluxes along the vehicle. Monte Carlo analyses of surface heat load for nine different vehicle nose radii was performed for both vehicles, assuming the same thermal protection system is used for both vehicles. The maximum heat loads …

Microsphere Based Patterning Of Metal Optic/Plasmonic Sensors Including Fiber Based Sensors, Edward C. Kinzel, Mahmoud Almasri, Chuang Qu, Ibrahem Jasim, Jiayu Liu

Patents

A fiber-based sensor and a method of forming a fiber-based sensor using microsphere lithography techniques in which a microsphere array is applied to a surface of a tip of an optical fiber to provide for microsphere lithography fabrication of a desired pattern on the tip of the optical fiber. The characteristics of the pattern define sensing capabilities of the sensor to provide for chemical and/or biological sensing.

Frequency-Selective Metasurface Integrated Uncooled Microbolometers, Mahmoud Almasri, Edward C. Kinzel

Patents

A metasurface integrated microbolometer having a sensing layer (e.g., SixGeyOI-x-y ). The presence of the metasurface provides selectivity with respect to wavelength, polarization and angle-of-incidence. The presence of the metasurface into the microbolometer affects conversion of electromagnetic to thermal energy, thermal response, electrical integration of the micro bolometer, and the tradeoff between resistivity and temperature coefficient of resistance, thereby allowing the ability to obtain a sensing with high temperature coefficient of resistance with lower resistivity values than that of films without the metasurface. The presence of the metasurface removes the need for a Fabry-Perot cavity.

Simulation And Modeling Of Hypersonic Turbulent Boundary Layers Subject To Adverse Pressure Gradients Due To Concave Streamline Curvature, Gary L. Nicholson, Junji Huang, Lian Duan, Meelan M. Choudhari

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct numerical simulations (DNS) of adverse-pressure-gradient turbulent boundary layers over a planar concave wall are presented for a nominal freestream Mach number of 5, with the objective of assessing the limitations of the currently available Reynolds-averaged Navier-Stokes (RANS) models. The wall geometry and flow conditions of the DNS are representative of the experimental data for a Mach 4.9 turbulent boundary layer that was tested on a two-dimensional planar concave wall model in the high-speed blow-down wind tunnel located at the National Aerothermochemistry Laboratory at Texas A&M University (TAMU). The DNS was validated against the experimental results of TAMU for the …

Quantum Inspired Concepts In Decision Making, Qizi Zhang

Doctoral Dissertations

"In this study, several new applications of quantum-inspired techniques are presented to advance the state of the art in decision making. In the first part, a quantum boost scheme for multiple-model filters based on extended Grover’s algorithm is presented for fault detection and parameter estimation. The quantum boost scheme accelerates the convergence of the posterior probabilities in the multiple-model filter. Stability proofs for the quantum boost scheme is presented and its performance is analyzed using benchmark examples. In the second part, the scope of application is extended to modeling human decision making. The open quantum system cognition model is applied …

Multiple-Site Fatigue Cracking Methodology To Assess Structural Integrity Of Aircraft Riveted Panels, Haroldo Chacon

Masters Theses

“Multiple Site Damage (MSD) is the most common source of Widespread Fatigue Damage (WFD) affecting structural integrity of aging aircraft fleets. Therefore, an understanding of its progression, the development of methods to prevent the onset, and the maintenance procedures precluding WFD are important to improve aircraft fleet longevity. A reliable and efficient numerical methodology to perform detailed Multiple Site Damage assessment in riveted structural joints was developed. A probabilistic methodology was employed in conjunction with Monte Carlo simulation technique; the fatigue initiation life at every potential crack initiation site was determined and initial damage scenarios were generated. Probabilistic crack growth …

Theoretical Study Of Magnetic Particles In A Shear Flow Subjected To A Uniform Magnetic Field, Christopher A. Sobecki

Doctoral Dissertations

"Magnetic manipulation of non-spherical magnetic microparticles is important for applications in shape-based and magnetic-based separations such as waste management, disease diagnostics, drug delivery, and mining. Manipulations of magnetic microparticles also include chain formation to assemble compositions for electronics, drug loading designs, and magnetorheological fluids for smart armor, hydraulic brakes, and dampers. In microfluidic devices, separation-formation-effectiveness depends on the shape of the channel, the shear rate, and the magnetic field strength and direction.

Particle separation and chain formation involved highly complex and computational expense-demanding studies in microfluidic devices, magnetic fields, and particle- particle/wall interactions. This research took complex experimental studies and …

Multi-Fidelity Modeling For Aerothermal Analysis Of Deployable Planetary Entry Technologies, Mario J. Santos

Doctoral Dissertations

“NASA is developing deployable entry technologies in the form of the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) and the Adaptable Deployable Entry Technology (ADEPT) vehicles to support human exploration of Mars. To ensure that these technologies are reliable under uncertain entry conditions and extreme aerothermal environments, uncertainty quantification must be integrated into the design process which typically requires large number of high-fidelity computational fluid dynamics (CFD) simulations with prohibitively high computational cost. To address this challenge, construction of multi-fidelity aerothermal response predictions which combine low-fidelity correlations with fewer high-fidelity CFD models in a way that produces highly accurate surrogates with reduced …

Reveal Wind Loading Of Tornadoes And Hurricanes On Civil Structures Towards Hazard-Resistant Design, Ryan Honerkamp

Doctoral Dissertations

"Extreme winds impacting civil structures lead to death and destruction in all regions of the world. Specifically, tornadoes and hurricanes impact communities with severe devastation. On average, 1200 tornadoes occur in the United States every year. Tornadoes occur predominantly in the Central and Southeastern United States, accounting for an annual $1 billion in economic losses, 1500 injuries, and 90 deaths. The Joplin, MO Tornado in 2011 killed 161 people, injured more than 1000, destroyed more than 8000 structures, and caused $2.8 billion of property loss. Hurricanes occur predominantly on the United States East coast regions and along the coast of …

Information-Based Methods And Models For Particle Flow Filtering, Kari Catherine Ward

Doctoral Dissertations

"Recursive estimation methodologies, such as Kalman and Bayesian filters, typically require models of some kind to perform the estimation. This filtering process seeks to improve knowledge surrounding some quantities of interest, or states, over time by incorporation of imperfect observations. The models required pertain to the state dynamics, sensors from which measurements are obtained, and probabilistic models of the underlying stochastic processes. In addition to any number of necessary models, real-world application of a filter is normally accompanied by at least one, if not several, techniques to promote better performance. These methods vary in purpose from expanding the kinds of …

Cooperative Navigation Of Small Satellites In The Deep Space Environment, Jill Christine Davis

Doctoral Dissertations

“The continued development of small satellites (SmallSats) has made them an increasingly viable mission alternative to traditional monolithic spacecraft. Constellations, swarms, and formations of these small spacecraft have the potential to fill unique gaps in the space systems architecture, while reducing overall mission costs and increasing mission redundancy. Cooperative navigation between spacecraft within swarms and formations is critical to mission success, but poses many challenges for SmallSats due to their size, mass, power, and computing constraints. While Earth orbiting missions can rely on GNSS data for high-accuracy inertial and relative navigation, deep space missions require new navigation techniques. In this …

Analysis Of Turbulence Model Uncertainty For Canonical Flow Problems Including Shock Wave Boundary Layer Interaction Simulations, Aaron James Erb

Doctoral Dissertations

"The purpose of this research is to present results of an uncertainty and sensitivity analysis study of commonly used turbulence models in Reynolds-Averaged Navier-Stokes (RANS) codes due to the epistemic uncertainty in closure coefficients for a set of turbulence model validation cases that represent the structure of several canonical flow problems. The study focuses on the analysis of a 2D zero pressure gradient flat plate, a 2D wall mounted hump, and an axisymmetric shock wave boundary layer interaction, all of which are well documented on the NASA Langley Research Center Turbulence Modeling Resource website. The Spalart-Allmaras (SA), the Wilcox (2006) …

Effect Of Nonlinear Mixing On Electrospray Propulsion Predictions, Mitchell J. Wainwright, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Efficient Solution Of Surface Erosion In Particle-Laden Hypersonic Flows, Andrew Hinkle, Serhat Hosder, Christopher Johnston

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The standard approach for simulating hypersonic dust erosion problems using mixed Eulerian-Lagrangian two-phase solvers is too computationally expensive for routine simulations, and particularly for uncertainty quantification (UQ) analyses. To enable these analyses, a new approach for solving this problem with a sparse set of particles is presented and demonstrated on a problem from literature involving the ExoMars Schiaparelli entry vehicle. This new approach, referred to here as the Trajectory Control Volume (TCV) method is verified against traditional approaches based on Monte Carlo, and is shown to require over 3 orders-of-magnitude less samples to obtain the same results. An example UQ …

Modeling Rack Force For Steering Maneuvers In A Stationary Vehicle, Nilay Kant, Raunav Chitkara, Prerit Pramod

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A steering system converts circular motion of the steering wheel into yaw motion of the road-wheels. In absence of a steering assist mechanism, the driver torque overcomes the tire-road friction forces, which is transmitted to the steering rack through tie rods attached to the road-wheels. The net force acting on the rack is then transmitted to the steering wheel through mechanical linkages which results in natural haptic feedback, commonly referred to as the steering feel. In an electric/hydraulic power steering, an electro-mechanical actuator applies assist force, which reduces the torque required by the driver. In order to maintain stability of …

Novel Adaptive Sampling Algorithm For Pod-Based Non-Intrusive Reduced Order Model, Jiachen Wang, Xiaosong Du, Joaquim R.R.A. Martins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The proper orthogonal decomposition (POD) based reduced-order model (ROM) has been an effective tool for flow field prediction in the engineering industry. The sample selection in the design space for POD basis construction affects the ROM performance sensitively. Adaptive sampling can significantly reduce the number of samples to achieve the required model accuracy. In this work, we propose a novel adaptive sampling algorithm, called conjunction sampling strategy, which is based on proven strategies. The conjunction sampling strategy is demonstrated on airfoil flow field prediction within the transonic regime. We demonstrate the performance of the proposed strategy by running 10 trials …

A Convolutional Neural Network Model Based On Multiscale Structural Similarity For The Prediction Of Flow Fields, Yifu An, Xiaosong Du, Joaquim R.R.A. Martins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We have seen the emerging applications of deep neural networks for flow field predictions in the past few years. Most of the efforts rely on the increased complexity of the model itself or take advantage of novel network architectures, such as convolutional neural networks (CNN). However, reaching low prediction error cannot guarantee the quality of the predicted flow fields in terms of the perceived visual quality. This work introduces the multi-scale structural similarity (MS-SSIM) index method for flow field prediction. First, we train CNN models using the commonly used root mean squared error (RMSE) loss function as the reference. Then …

Laser-Based Interfacial Patterning Enables Toughening Of Cfrp/Epoxy Joints Through Bridging Of Adhesive Ligaments, Ran Tao, Xiaole Li, Arief Yudhanto, Marco Alfano, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The ability to prevent catastrophic failures in secondary bonded CFRP adhesive joints is important for reliable automotive and aerospace structures. In a previous study, we proposed an innovative damage-tolerant interfacial design concept for adhesively bonded composite joints, which relied on the extrinsic dissipation of bridging adhesive ligaments enabled by controlling the adhesion at CFRP/epoxy interfaces. In this work, we experimentally validate this strategy by combining laser processing and mechanical testing using double cantilever beam (DCB) joints. Mechanical tests indicate that the pattern geometry, i.e., number and spacing of the areas with different adhesion, controls the formation of either single or …

Modular Framework For Implementation And Analysis Of Recursive Filters With Considered And Neglected Parameters, Kyle J. Demars, Kari C. Ward

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper develops novel covariance and square-root factor formulations of a consider-neglect Kalman filter for navigation applications. The proposed filter partitions system parameters into three distinct categories: those to be estimated by the filter, those whose contribution to the system are considered without being explicitly estimated, and those with sufficiently low effect on the system such that their contribution can be neglected altogether. Discussion on appropriate selection of parameters to be considered and neglected is provided with specific attention given to descent-to-landing navigation. Monte Carlo simulations and analysis are performed to assess the performance of the developed square-root consider-neglect filter …

Coalescence Speed Of Two Equal-Sized Nanobubbles, Eric Bird, Jun Zhou, Zhi Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In This Work, We Use Molecular Dynamics (MD) Simulations Coupled with Continuum-Based Theoretical Analysis to Study the Coalescence Dynamics of Two Equal-Sized Nanobubbles (NBs). We First Derive a Governing Equation for the Evolution of the Capillary Bridge Radius between Two Coalescing NBs from the Axisymmetric Navier-Stokes Equation. to Verify the Prediction from the Governing Equation, We Carry Out MD Simulations of the Coalescence of Two NBs in a Lennard-Jones Fluid System and Directly Measure the Bridge Radius, Rb, as a Function of Time, T. by Varying the Bubble Diameter, We Change the NB Ohnesorge Number from 0.46 to 0.33. in …

Efficient Yield Estimation Of Multiband Patch Antennas By Polynomial Chaos-Based Kriging, Leifur Leifsson, Xiaosong Du, Slawomir Koziel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Yield estimation of antenna systems is important to check their robustness with respect to the uncertain sources. Since direct Monte Carlo sampling of accurate physics-based models can be computationally intensive, this work proposes the use of the polynomial chaos–Kriging (PC-Kriging) metamodeling method for fast yield estimation of multiband patch antennas. PC-Kriging integrates the polynomial chaos expansion (PCE) as the trend function of Kriging metamodel since the PCE is good at capturing the function tendency and Kriging is good at matching the observations at training points. The PC-Kriging method is demonstrated on two analytical cases and two multiband patch antenna cases …

Enhancement Of Fracture Toughness In Secondary Bonded Cfrp Using Hybrid Thermoplastic/Thermoset Bondline Architecture, A. Yudhanto, M. Almulhim, F. Kamal, R. Tao, L. Fatta, M. Alfano, G. Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Structures made of carbon fiber-reinforced polymer (CFRP) can be assembled using adhesive bonding. However, such bonding is prone to brittle delamination, and a method to improve delamination resistance is desirable. Here, we propose a technique to introduce crack-arrest features that increase the R-curve response by engineering the adhesive bond line/interface. We specifically designed a wavy net-like thermoplastic insert that was embedded into the thermoset adhesive bond line where the new mechanisms of energy dissipation were generated. We demonstrate that the technique is effective at improving mode I fracture toughness of secondary bonded carbon/epoxy by more than 400%. The hybrid thermoset/thermoplastic …

Maximum Evaporating Flux Of Molecular Fluids From A Planar Liquid Surface, Eric Bird, Zhi Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In This Work, We Use the Kinetic Theory of Gases (KTG) to Develop a Theoretical Model to Understand the Role of Internal Motions of Molecules on the Maximum Evaporation Flux from a Planar Liquid Surface. the Kinetic Theory is Applied to Study the Evaporation of Molecular Fluids into a Vacuum and Predict the Dimensionless Maximum Evaporation Flux (JR,max, I.e., the Ratio of the Maximum Evaporation Flux to the Molar Flux Emitted from a Liquid Surface). the Key Assumptions Regarding the Velocity Distribution Function (VDF) of Polyatomic Molecules in the Highly Nonequilibrium Vapor Near the Evaporating Surface Are Validated by the …

Review Of Multimode Space Propulsion, Joshua L. Rovey, Christopher T. Lyne, Alex J. Mundahl, Nicolas Rasmont, Matthew S. Glascock, Mitchell J. Wainwright, Steven P. Berg

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multimode propulsion is the integration of two or more propulsive modes with shared propellant into a single spacecraft propulsion system. Multimode propulsion is emerging as an enabling technology that promises enhanced capabilities for spacecraft and space missions and can therefore play an important role in the future of in-space propulsion. Multimode propulsion has the potential to provide unprecedented flexibility and adaptability to spacecraft as a direct result of shared propellant and can provide mass savings for certain missions. These benefits can apply regardless of spacecraft size. Additional mass savings may be realized by sharing thruster hardware between modes, especially for …

Inkjet-Printed Ti3c2tx Mxene Electrodes For Multimodal Cutaneous Biosensing, Abdulelah Saleh, Shofarul Wustoni, Eloise Bihar, Jehad K. El-Demellawi, Yizhou Zhang, Adel Hama, Victor Druet, Arief Yudhanto, Gilles Lubineau, Husam N. Alshareef, Sahika Inal

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Among the existing two-dimensional materials, MXenes, i.e. transition metal carbides, nitrides and/or carbonitrides, stand out for their excellent electrochemical properties. Due to their high charge storage capacity, metal-like conductivity, biocompatibility as well as hydrophilicity, Ti3C2Tx MXene-based inks hold great potential for scalable production of skin conformable electronics via direct printing methods. Herein, we develop an aqueous MXene ink and inkjet-print MXene films on freestanding, flexible, and conducting polymer-based substrates. These skin-adherent MXene electrodes detect electrocardiography signals with high signal-to-noise ratio while exhibiting preserved electrical performance after 1000 cycles of bending with a 50 d long shelf life in ambient conditions. …

Asymmetric Semiconductor Nanostructures For Particle Manipulation, Jaykob Maser, Joshua Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We explore how material selection affects the electromagnetic response of closely positioned asymmetric nanostructures. COMSOL Multiphysics is used to model the system, and the materials studied include gold (Au), gallium arsenide (GaAs), indium tin oxide (ITO), and aluminum zinc oxide (AZO). All materials produce average electric field magnitudes on the order of 10 MV/m. We conclude that the ITO and AZO nanostructures produce the most uniform electric field response over the entire domain of incident wavelengths and that GaAs is least thermally stable in a vacuum environment due to its low heat conductivity.