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Development And Testing Of A Hydrogen Peroxide Injected Thrust Augmenting Nozzle For A Hybrid Rocket, Mark C. Heiner 2019 Utah State University

Development And Testing Of A Hydrogen Peroxide Injected Thrust Augmenting Nozzle For A Hybrid Rocket, Mark C. Heiner

All Graduate Theses and Dissertations

During a rocket launch, the point at which the most thrust is needed is at lift-off where the rocket is the heaviest since it is full of propellant. Unfortunately, this is also the point at which rocket engines perform the most poorly due to the relatively high atmospheric pressure at sea level. The Thrust Augmenting Nozzle (TAN) investigated in this paper provides a solution to this dilemma. By injecting extra propellant into the nozzle but downstream of the throat, the internal nozzle pressure is raised and the thrust is increased, and the nozzle efficiency, or specific impulse is potentially improved ...


Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim 2019 Singh Center for Nanotechnology

Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim

Tool Data

S1805 positive photoresist has been deposited on single crystalline Si wafers using a Suss MicroTec Alta Spray. The influence of flow rate, nozzle speed, pitch and number of passes on the thickness of the photoresist was studied. Results show that the thickness of S1805 is linearly proportional to the flow rate and number of passes, and inversely proportional to the nozzle speed and pitch.


Tensorial Stress−Strain Fields And Large Elastoplasticity As Well As Friction In Diamond Anvil Cell Up To 400 Gpa, Valery I. Levitas, Mehdi Kamrani, Biao Feng 2019 Iowa State University and Ames Labortory

Tensorial Stress−Strain Fields And Large Elastoplasticity As Well As Friction In Diamond Anvil Cell Up To 400 Gpa, Valery I. Levitas, Mehdi Kamrani, Biao Feng

Valery I. Levitas

Various phenomena (fracture, phase transformations, and chemical reactions) studied under extreme pressures in diamond anvil cell are strongly affected by fields of all components of stress and plastic strain tensors. However, they could not be measured. Here, we suggest a coupled experimental−theoretical−computational approach that allowed us (using published experimental data) to refine, calibrate, and verify models for elastoplastic behavior and contact friction for tungsten (W) and diamond up to 400 GPa and reconstruct fields of all components of stress and large plastic strain tensors in W and diamond. Despite the generally accepted strain-induced anisotropy, strain hardening, and path-dependent ...


Incorporation Of Composite Defects From Ultrasonic Nde Into Cad And Fe Models, Onur Rauf Bingol, Bryan Schiefelbein, Robert J. Grandin, Stephen D. Holland, Adarsh Krishnamurthy 2019 Iowa State University

Incorporation Of Composite Defects From Ultrasonic Nde Into Cad And Fe Models, Onur Rauf Bingol, Bryan Schiefelbein, Robert J. Grandin, Stephen D. Holland, Adarsh Krishnamurthy

Stephen D. Holland

Fiber-reinforced composites are widely used in aerospace industry due to their combined properties of high strength and low weight. However, owing to their complex structure, it is difficult to assess the impact of manufacturing defects and service damage on their residual life. While, ultrasonic testing (UT) is the preferred NDE method to identify the presence of defects in composites, there are no reasonable ways to model the damage and evaluate the structural integrity of composites. We have developed an automated framework to incorporate flaws and known composite damage automatically into a finite element analysis (FEA) model of composites, ultimately aiding ...


Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song 2019 Iowa State University

Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song

William Q Meeker

Probability of detection (POD) is widely used for measuring reliability of nondestructive testing (NDT) systems. Typically, POD is determined experimentally, while it can be enhanced by utilizing physics-based computational models in combination withmodel-assisted POD (MAPOD) methods. With the development of advanced physics-basedmethods, such as ultrasonic NDTtesting, the empirical information,needed for POD methods, can bereduced. However, performing accurate numerical simulationscan be prohibitivelytime-consuming, especially as part of stochastic analysis. In this work, stochastic surrogate models for computational physics-based measurement simulations are developed for cost savings of MAPOD methods while simultaneously ensuring sufficient accuracy. The stochastic surrogate is used to propagate the ...


Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song 2019 Iowa State University

Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song

Jiming Song

Probability of detection (POD) is widely used for measuring reliability of nondestructive testing (NDT) systems. Typically, POD is determined experimentally, while it can be enhanced by utilizing physics-based computational models in combination withmodel-assisted POD (MAPOD) methods. With the development of advanced physics-basedmethods, such as ultrasonic NDTtesting, the empirical information,needed for POD methods, can bereduced. However, performing accurate numerical simulationscan be prohibitivelytime-consuming, especially as part of stochastic analysis. In this work, stochastic surrogate models for computational physics-based measurement simulations are developed for cost savings of MAPOD methods while simultaneously ensuring sufficient accuracy. The stochastic surrogate is used to propagate the ...


Surrogate Modeling Of Ultrasonic Simulations Using Data-Driven Methods, Xiaosong Du, Robert J. Grandin, Leifur Leifsson 2019 Iowa State University

Surrogate Modeling Of Ultrasonic Simulations Using Data-Driven Methods, Xiaosong Du, Robert J. Grandin, Leifur Leifsson

Robert Grandin

Ultrasonic testing (UT) is used to detect internal flaws in materials and to characterize material properties. In many applications, computational simulations are an important part of the inspection-design and analysis processes. Having fast surrogate models for UT simulations is key for enabling efficient inverse analysis and model-assisted probability of detection (MAPOD). In many cases, it is impractical to perform the aforementioned tasks in a timely manner using current simulation models directly. Fast surrogate models can make these processes computationally tractable. This paper presents investigations of using surrogate modeling techniques to create fast approximate models of UT simulator responses. In particular ...


Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song 2019 Iowa State University

Model-Assisted Probability Of Detection Of Flaws In Aluminum Blocks Using Polynomial Chaos Expansions, Xiaosong Du, Leifur Leifsson, Robert J. Grandin, William Q. Meeker, Ronald A. Roberts, Jiming Song

Robert Grandin

Probability of detection (POD) is widely used for measuring reliability of nondestructive testing (NDT) systems. Typically, POD is determined experimentally, while it can be enhanced by utilizing physics-based computational models in combination withmodel-assisted POD (MAPOD) methods. With the development of advanced physics-basedmethods, such as ultrasonic NDTtesting, the empirical information,needed for POD methods, can bereduced. However, performing accurate numerical simulationscan be prohibitivelytime-consuming, especially as part of stochastic analysis. In this work, stochastic surrogate models for computational physics-based measurement simulations are developed for cost savings of MAPOD methods while simultaneously ensuring sufficient accuracy. The stochastic surrogate is used to propagate the ...


Utsim2 Validation, Robert J. Grandin, Tim Gray 2019 Iowa State University

Utsim2 Validation, Robert J. Grandin, Tim Gray

Robert Grandin

The Center for NDE (CNDE) at Iowa State University has a long history of developing physics models for NDE and packaging these models into simulation tools which make the modeling capabilities accessible to CNDEs industrial sponsors. Recent work at CNDE has led to the development of a new ultrasonic simulation package, UTSim2, which aims to continue this tradition of supporting industrial application of CNDE models. In order to meet this goal, UTSim2 has been designed as an extensible software package which can support previously-developed physics models as well as future models yet to be developed. Initial work has focused on ...


Incorporation Of Composite Defects From Ultrasonic Nde Into Cad And Fe Models, Onur Rauf Bingol, Bryan Schiefelbein, Robert J. Grandin, Stephen D. Holland, Adarsh Krishnamurthy 2019 Iowa State University

Incorporation Of Composite Defects From Ultrasonic Nde Into Cad And Fe Models, Onur Rauf Bingol, Bryan Schiefelbein, Robert J. Grandin, Stephen D. Holland, Adarsh Krishnamurthy

Robert Grandin

Fiber-reinforced composites are widely used in aerospace industry due to their combined properties of high strength and low weight. However, owing to their complex structure, it is difficult to assess the impact of manufacturing defects and service damage on their residual life. While, ultrasonic testing (UT) is the preferred NDE method to identify the presence of defects in composites, there are no reasonable ways to model the damage and evaluate the structural integrity of composites. We have developed an automated framework to incorporate flaws and known composite damage automatically into a finite element analysis (FEA) model of composites, ultimately aiding ...


Dear Neil Armstrong: Letters To The First Man From All Mankind, James R. Hansen 2019 Purdue University

Dear Neil Armstrong: Letters To The First Man From All Mankind, James R. Hansen

Purdue University Press Book Previews

In the years between the historic first moon landing by Apollo 11 on July 20, 1969, and his death at age 82 on August 25, 2012, Neil Armstrong received hundreds of thousands of cards and letters from all over the world, congratulating him, praising him, requesting pictures and autographs, and asking him what must have seemed to him to be limitless—and occasionally intrusive—questions. Of course, all the famous astronauts received fan mail, but the sheer volume Armstrong had to deal with for more than four decades after his moon landing was staggering.

Today, the preponderance of those letters ...


Tensorial Stress−Strain Fields And Large Elastoplasticity As Well As Friction In Diamond Anvil Cell Up To 400 Gpa, Valery I. Levitas, Mehdi Kamrani, Biao Feng 2019 Iowa State University and Ames Labortory

Tensorial Stress−Strain Fields And Large Elastoplasticity As Well As Friction In Diamond Anvil Cell Up To 400 Gpa, Valery I. Levitas, Mehdi Kamrani, Biao Feng

Aerospace Engineering Publications

Various phenomena (fracture, phase transformations, and chemical reactions) studied under extreme pressures in diamond anvil cell are strongly affected by fields of all components of stress and plastic strain tensors. However, they could not be measured. Here, we suggest a coupled experimental−theoretical−computational approach that allowed us (using published experimental data) to refine, calibrate, and verify models for elastoplastic behavior and contact friction for tungsten (W) and diamond up to 400 GPa and reconstruct fields of all components of stress and large plastic strain tensors in W and diamond. Despite the generally accepted strain-induced anisotropy, strain hardening, and path-dependent ...


Evaluation Of The Fidelity Of Feature Descriptor-Based Specimen Tracking For Automatic Nde Data Integration, Rafael Radkowski, Stephen D. Holland, Robert J. Grandin 2019 Iowa State University

Evaluation Of The Fidelity Of Feature Descriptor-Based Specimen Tracking For Automatic Nde Data Integration, Rafael Radkowski, Stephen D. Holland, Robert J. Grandin

Robert Grandin

This research addresses inspection location tracking in the field of nondestructive evaluation (NDE) using a computer vision technique to determine the position and orientation of typical NDE equipment in a test setup. The objective is the tracking accuracy for typical NDE equipment to facilitate automatic NDE data integration. Since the employed tracking technique relies on surface curvatures of an object of interest, the accuracy can be only experimentally determined. We work with flash-thermography and conducted an experiment in which we tracked a specimen and a thermography flash hood, measured the spatial relation between both, and used the relation as input ...


A Test-Bed For Measuring Uas Servo Reliability, AbdElRahman ElSaid, Daniel Kwasi Adjekum, John Nordlie, Fatima El Jamiy 2019 University of North Dakota

A Test-Bed For Measuring Uas Servo Reliability, Abdelrahman Elsaid, Daniel Kwasi Adjekum, John Nordlie, Fatima El Jamiy

Aviation Faculty Publications

Extant literature suggests minimal research on the reliability of Commercial off-the-shelf (COTS) components used in fabricating non-military Unmanned Aerial System (UAS). Stochastic failures of components during operational cycles over time poses a safety hazard to flight operations. The purpose of the study was to critically assess the operational performance standards (reliability) of a laboratory designed UAS component test-bed operated using real-world data collected from a Boeing Scan Eagle® UAS aileron servo unit via a flight data recorder. The study hypothesized that the test-bed’s reliability, in terms of a measured encoder output of commanded servo positions, will not be significantly ...


Thermal Bending, Buckling And Post-Buckling Analysis Of Unsymmetrically Laminated Composite Beams With The Effects Of Moisture And Geometric Imperfections, Claudia Barreno 2019 Embry-Riddle Aeronautical University

Thermal Bending, Buckling And Post-Buckling Analysis Of Unsymmetrically Laminated Composite Beams With The Effects Of Moisture And Geometric Imperfections, Claudia Barreno

Dissertations and Theses

This thesis is concerned with the analytical study of the thermal bending, buckling, and post-buckling of unsymmetrically laminated composite beams with imperfection under hygrothermal effects. Three different boundary conditions will be considered on this study. The non-linear governing partial differential equations are derived by taking into account the von-Karman geometrical nonlinearity for an imperfect unsymmetrical laminated composite beam. Classical beam theory (CBT) as well as first order shear deformation theory (FSDT) will be used. The effects of temperature, angle of orientation, moisture variations, imperfection, and geometrical parameters, will be evaluated and discussed. Two different laminated composite laminates will be considered ...


Hybrid Structural Composites With Energy Harvesting Capabilities, Simon Furnes 2019 Embry-Riddle Aeronautical University

Hybrid Structural Composites With Energy Harvesting Capabilities, Simon Furnes

Dissertations and Theses

Hybrid materials have received significant interest due to the potential enhancements they provide over traditional materials such as sensing, actuating, energy scavenging, thermal management, and vibration damping. While traditional materials can be utilized for either one of these functions or loadbearing, the hybrid materials are superior as they allow combination of a wide array of functionalities whilst being suitable for load-bearing purposes.

The goal of this thesis is to elucidate the synergistic effects of hybridization of two piezoelectric materials; zinc oxide nanowires (ZnO NWs) and thin film of lead zirconium titanate (PZT) on the mechanical and energy harvesting of beams ...


Effects Of Carbon-Based Ablation Products On Hypersonic Boundary Layer Stability, Olivia S. Elliot 2019 Air Force Institute of Technology

Effects Of Carbon-Based Ablation Products On Hypersonic Boundary Layer Stability, Olivia S. Elliot

Theses and Dissertations

Hypersonic vehicles require an accurate prediction of the transition of the boundary layer for the design of the thermal protection system due to the high heating rates under turbulent flow. Many thermal protection systems are carbon-based and introduce new species, specifically CO2, into the boundary layer flow which are known to dampen the instabilities that lead to transition for hypersonic vehicles. A Computation Fluid Dynamics study was accomplished examining the concentration of CO2 required to impact boundary layer transition over both sharp and blunt cones. These results were used in conjunction with air-carbon ablation models models to determine if ...


Cubesat Astronomy Mission Modeling Using The Horizon Simulation Framework, Alexander W. Johnson 2019 California Polytechnic State University, San Luis Obispo

Cubesat Astronomy Mission Modeling Using The Horizon Simulation Framework, Alexander W. Johnson

Master's Theses and Project Reports

The CubeSat Astronomy Network is a proposed system of multiple CubeSat spacecraft capable of performing follow-up observations of astronomical targets of interest. The system is intended to serve as a space-borne platform that can complement existing systems utilized for astronomical research by undergraduate and high school students. Much research and development work has been performed to develop model-based system engineering methodologies and products for CubeSat missions, including the Horizon Simulation Framework. The Horizon Simulation Framework enables the development of system models using the Extended Markup Language (XML), and its simulation program can generate system simulations over model-specified timespans. System requirements ...


Multimode Nonlinear Vibration Analysis Of Stiffened Functionally Graded Double Curved Shells In A Thermal Environment, Boutros Azizi 2019 Embry-Riddle Aeronautical University

Multimode Nonlinear Vibration Analysis Of Stiffened Functionally Graded Double Curved Shells In A Thermal Environment, Boutros Azizi

Dissertations and Theses

The motivation of the current work is to develop a multi-modal analysis of the nonlinear response of stiffened double curved shells made of functionally graded materials under thermal loads. The formulation is based on the first order shear deformation shell theory in conjunction with the von Kármán geometrical nonlinear strain-displacement relationships. The nonlinear equations of motion of stiffened double curved shell based on the extended Sanders’s theory were derived using Galerkin’s method. The resulting system of infinite nonlinear ordinary differential equations, that includes both cubic and quadratic nonlinear terms, was solved using a nonlinear dynamic software XPPAUT to ...


A Volume-Force Synthetic Disturbance Approach For High-Fidelity Of Unsteady Fluid Structure Interactions, Marina Kazarina 2019 Embry-Riddle Aeronautical University

A Volume-Force Synthetic Disturbance Approach For High-Fidelity Of Unsteady Fluid Structure Interactions, Marina Kazarina

Dissertations and Theses

The purpose of this dissertation is to analyze the momentum source model, for generating synthetic vortical disturbance field in numerical simulations of unsteady fluid-structure interactions, access limitations of this approach, to find requirements for the computational domain, space and time resolution, and apply this model to investigate selected physical problems. For this reason a comprehensive parametric study of volume-force based method of generating spectral synthetic turbulence inside the computational domain is conducted first. The method is then extended to synthesize turbulence with arbitrary energy spectrum. The synthetic turbulence is generated through momentum source terms in Navier-Stokes equations, and the developed ...


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