Mechanical Engineering Commons^™

Effects Of Process-Induced Defects On The Corrosion Of Additively Manufactured Stainless Steel 304l, Leila Saberi, Frank W. Liou, Mehdi Amiri

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This Study Investigates the Impact of Process-Induced Defects Such as Gas Pores, Lack of Fusions, and Surface Roughness on Corrosion Behavior of Stainless Steel 304L (SS304L) Fabricated by Laser Powder Bed Fusion Additive Manufacturing. Specimens Are Printed with Optimized Process Parameters but Selected from Different Locations on the Build Plate. Parallel and Perpendicular Surfaces to the Build Direction Are Investigated and Compared with Corrosion Properties of Wrought SS304L in 5 Wt% NaCl. the Results Reveal Significant Difference in Corrosion Behavior among Specimens Due to Variations in their Defect Features. Pitting Potential, Pit Initiation, and Growth Rates Are Found to Be …

Effect Of Pre-Heating On Residual Stresses And Deformation In Laser-Based Directed Energy Deposition Repair: A Comparative Analysis, Usman Tariq, Sung Heng Wu, Muhammad Arif Mahmood, Michael M. Woodworth, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser-Directed Energy Deposition (DED), a Metal Additive Manufacturing Method, is Renowned for its Role in Repairing Parts, Particularly When Replacement Costs Are Prohibitive. Ensuring that Repaired Parts Avoid Residual Stresses and Deformation is Crucial for Maintaining Functional Integrity. This Study Conducts Experimental and Numerical Analyses on Trapezoidal Shape Repairs, Validating Both the Thermal and Mechanical Models with Experimental Results. Additionally, the Study Presents a Methodology for Creating a Toolpath Applicable to Both the DED Process and Abaqus CAE Software. the Findings Indicate that Employing a Pre-Heating Strategy Can Reduce Residual Stresses by over 70% Compared to No Pre-Heating. However, Pre-Heating …

Blade Design And Validation Of Hydrokinetic Turbine To Harvest Water Current Energy, Setare Sadeqi

LSU New Orleans Theses and Dissertations

The innovative aspect of this research lies in the careful integration of cutting-edge technologies throughout the entire process of designing, fabricating, and testing the carbon fiber propeller for the 3-bladed horizontal axis ocean current turbine (OCT). SolidWorks software played a pivotal role in the initial design phase, enabling a meticulous and precise modeling of the propeller's geometry. The utilization of SolidWorks allowed for a detailed exploration of various design parameters, ensuring that the propeller's structure and form were optimized for performance in ocean current conditions. Moving beyond the realm of virtual design, the choice of carbon fiber as the fabrication …

Investigation On The Effects Of Biofouling On The Boundary Layer, Adam N. Bacon

LSU New Orleans Theses and Dissertations

This study is an investigation of the effect of biofouling on the boundary layer of a flat plate and a NACA 4-digit series foil. Three identical hydrofoils made of resin were placed in the Gulf of Mexico at Grand Isle, Louisiana, and observed and analyzed by marine biologists at the University of New Orleans for their species composition. The resulting biofouling that grew was primarily made up of barnacles and bryozoans. The foils were submerged in an open channel flume at zero incidence and subjected to a series of experiments whose arc-length Reynolds numbers ranged from approximately 13000 to 32000. …

Towing Tank Trials Of Hydrokinetic Turbine Scale Model To Support Marine Energy System Verification, Shahab Rouhi

LSU New Orleans Theses and Dissertations

In response to the escalating demand for sustainable energy solutions and the critical reevaluation of conventional fossil fuels due to environmental concerns, this dissertation embarks on a comprehensive exploration of hydrokinetic energy as a promising alternative. The study delves into the underexplored domain of hydrokinetic energy, leveraging innovative methodologies for effective utilization and harnessing, particularly through the development and investigation of hydrokinetic turbines.

In the realm of hydrokinetic energy conversion, our research has exclusively concentrated on horizontal-axis turbines, distinct from other turbine configurations. Noteworthy is the adaptation of a conventional horizontal-axis wind turbine for water currents, revealing enhanced performance through …

Relations Between Printability And Rheology In A Ceramic Paste Extrusion Process, Nicholas Durand

Open Access Theses & Dissertations

Ceramic additive manufacturing (AM) uses the same fundamentals as material extrusion (MEX) that utilizes polymers or resins for printing applications. Ceramic AM uses the same process of slicing an STL file to determine a toolpath for the printer that will facilitate material deposition to manufacture full parts; ceramic AM also provides a low-cost advantage when compared to processes that require high powered lasers for melting metal powders or heated nozzles used for dispensing thermoplastics. Despite having the similar design freedom and ability for rapid prototyping that other printing methods benefit from with the addition of low cost, ceramic AM has …

Development, Modeling, Identification, And Control Of Tilt-Rotor Evtol Aircraft, Clayton T. Spencer

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis includes the development, modeling, identification, and control of an electric-Vertical-Take-Off-and-Landing (eVTOL) aircraft with tiltable rotors. The front two rotors have tilting capability for transition flight from vertical-take-off to forward-level flight. This work details the development of an eVTOL aircraft and the selection of sub components such as electric motors, batteries, and controllers. After the aircraft build, mathematical model is derived to describe the motion of the aircraft. Unknown parameters in the mathematical model are identified using a Least-Squares-regression (LSR) method that can handle parameter constraints. This is done using real flight data collected from the aircraft. Lastly, this …

Experimental And Numerical Analysis Of Laminar And Transitional Flow Through Annular Corrugated Pipes, Joseph Russell Sargent

Theses and Dissertations

This dissertation presents studies on pressure loss through annular corrugated pipes to determine a friction factor coefficient using nitrogen. Ten different corrugated pipes’ geometries were evaluated via testing and experimentation. The ratio of corrugation height to inner diameter varied from 0.233 to 0.333 and the ratio of corrugation pitch to inner diameter varied from 0.181 to 0.446. Nitrogen flow rates between 0.25 to 94.4 standard liters per minute were used, resulting in Reynolds numbers, based on the corrugated pipe inner diameter, from 100 to 23,000. The experimental set-up was validated using smooth-pipe pressure loss measurements and the derived friction factor …

System Identification For Motion Control Of Unmanned Aerial Vehicles Platform, Raj Ramesh Agarwal

Theses and Dissertations

Comprehensive research on Unmanned Aerial Vehicles (UAV) system identification for motion control parameters is presented in this thesis, with a focus on the necessity of precise control and improved performance. Using Pseudorandom Binary Sequence (PRBS) and Normally Distributed Random Numbers, it presents a unique technique for excitation of UAV dynamic systems. It also shows how effective random signals are in time-domain identification for precise control in a range of flying circumstances. The piece of research includes a thorough analysis and implementation of various approaches and its further improvements, highlighting the benefits and drawbacks of each. These approaches include the free …

Performance Effects Of Dissociated Hydrogen In Nuclear Thermal Propulsion Engines, Richard Adam Gorrell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nuclear thermal propulsion (NTP) research considers hydrogen dissociation as negligible to design and analysis of propulsion engines. This study reintroduces chemically reacting flow to NTP engine analysis for investigation of the dissociation effect on engine performance. A first-principles approach observes the basic chemical mechanism and reaction within the high-speed, high-temperature NTP flow to baseline expected atomic hydrogen levels and validate equilibrium. A surface reaction study looks into hydrogen absorption through dissociation and its effect on the boundary layer, and bulk flow. For total performance, the resulting dissociated flow is analyzed through nozzle expansion and performance metrics calculated.

All historic reactor …

Reducing Glass Loss During Transportation And Storage, Abdulaziz Muzafarovich Qurbanov, Mirzaabdullayev Jaxongir Baxtiyorovich

Technical science and innovation

The article discusses the processes of transportation and storage of sheet glass in the production of protective glass for cars. The experience of organizing the transportation and storage of glass in developed countries of the world was analyzed in order to study the problems of losses of raw materials during the transportation and storage of laminated glass, as well as to develop and approve a regulatory and technical document. in this field. The supplies of various brands of polished laminated glass used in the production of protective glass for cars to Avtooina LLC from different addresses, from different manufacturers were …

Aerodynamic Design And Analysis Of A Modified 2006 Mazda Miata, William N. Recher

Honors College Theses

Aerodynamic forces developed by automobiles have destabilizing effects at high speed. These forces tend to skew toward a vehicle’s rear which can present safety concerns, especially for rear-wheel-drive automobiles like the Mazda Miata. To address oversteer and high-speed instability, a vehicle’s design can be tailored to bring about aerodynamic balance and improve traction. LiDAR was used to bring the physical automobile into the digital space. Then, a splitter and diffuser were added to reduce the magnitude of the destabilizing forces. Next, the size and shape of the rear-wing required to balance the vehicle was calculated using a combination of parameters …

Experimental Investigation Of Various Hydrogen Knock Limit Extension Strategies On A Hydrogen-Gasoline Dual Fuel Spark Ignition Engine, Sanad Puthan Purayil

Thesis/ Dissertation Defenses

Hydrogen is a clean and carbon free substitute with the ability to significantly cut down the harmful emissions while enhancing the energy efficiency of internal combustion engines (ICE) typically powered by conventional fossil fuels. Hydrogen is the most abundant element which can be easily obtained from sources like water and biomass. The wide flammability range and high laminar flame velocity outstands hydrogen from other fuels. However, hydrogen fueled engines are more prone to abnormal combustion like knock and backfire due to its low ignition energy and high adiabatic flame temperature. To avoid backfire, several well-developed approaches have been reported. Unlike …

Ferroresonance In Three-Phase Electrical Networks, Shavkat Ernstovich Begmatov

Technical science and innovation

Possible modes of ferroresonance in three-phase electric networks and analysis of substitution schemes where ferroresonance voltage increase is observed are considered. The most complete magnetization curve of the transformer core and the analysis of the generalized equivalent substitution scheme are presented, as a result of which more accurate formulas for determining the values of equivalent parameters of the electrical network and voltage transformer in ferroresonance mode are obtained. Factor of ferroresonance voltage increase is introduced, which determines ratio between amplitude values of transformer phase voltage and mains voltage. The method of determination of boundary conditions of steady ferroresonance voltage increase …

Main Prospects Of Natural Gas Purification Technologies From Acidic Compounds, Oybek Yusupdjanovich Aripdjanov, Diyora Zokhid Qizi Khayrullaeva, Jonibek Avazek Ogli Abdumuminov

Technical science and innovation

The article discusses the main prospects for the technology of purifying natural gas from acidic components and the problems of ensuring the purity of oil and gas products in accordance with state standards. An increase in the degree of purification from H₂S, CO₂, elemental sulfur, carbonyl sulfide, ethyl mercaptans (thiols), methyl mercaptan, carbon disulfide, sulfides, disulfides (dithioethers), thiophene, sulfoxides and sulfones is considered. Also, the physicochemical properties of the absorbent for the purification of sulfur compounds (generated during natural gas processing) are studied. Based on the study of various absorbents (ethanolamine (EA), methylethanolamine (MEA), diethanolamine (DEA), …

Synthesis And Structure-Property Relationships Of Sustainable Nanostructured Materials Towards Energy And Environment Applications, Nizamudeen Alungal Cherupurakal

Thesis/ Dissertation Defenses

This doctoral research aims to advance clean energy technologies by developing specialized nanostructured materials. The study covers significant research themes, each forming separate sections in the thesis, explaining the important role of nanostructures in enhancing the efficiency and sustainability of energy devices and photocatalytic technologies. The enduring effort toward stabilizing and improving the efficiency of dye-sensitized solar cells (DSSCs) has stirred the solar research community to follow innovative approaches. The primary objective of the research is centered on electrode materials design, which improves photoanodes' light-harvesting efficiency (LHE). To improve the Photoanode of DSSCs, a Metal-Organic Framework (MOF) derived porous photoanodes …

Friction Stir Welding Of Tube-To-Tubesheet And Spot Joints For Virgin And Recycled Thermoplastic Materials., Syed Haris Iftikhar

Thesis/ Dissertation Defenses

Thermoplastic materials are becoming popular, due to their chemically inert and anti-fouling properties, for use in industrial heat exchanger applications involving heating/cooling of highly reactive fluids like acids. A novel nonconventional joining framework, based on the friction stir welding (FSW) technique, is developed to create high-quality thermoplastic tube-to-tubesheet joints (TTJs). The proposed technique has applications in the thermoplastic shell-andtube heat exchanger and piping industries (as flange-to-pipe joints). The primary objective is to study the feasibility of the FSW technique for developing thermoplastic TTJs, followed by optimization of the process parameters and detailed material characterizations. This work used workpieces (tube, tubesheet) …

Offshore Wind Farm Pycnocline Mixing From Varied Flow Types, Laura Lundahl

Student Research Symposium

As the demand for sustainable low carbon energy grows, offshore wind farms (OWFs) are becoming increasingly popular and are being pushed into stratified regions where a pycnocline exists (Figure 1). These wind farms may cause turbulent mixing of the pycnocline, which will harm the phytoplankton ecosystem. This project quantifies pycnocline mixing to gain knowledge of effective methods for mitigating harmful effects.

Using Efficient Global Optimization With Cfd For Aerodynamic Optimization, Aaron Spillars, Nathan Roberts, Xiaoping Du

Undergraduate Research Conference at Missouri S&T

Machine learning and optimization are the stepping blocks in broad engineering areas, such as computational fluid dynamics (CFO) and CFO-based design optimization. Using the CFO-based optimization framework, MACH-Aero, we were able to use the SLSQP optimizer and compared the results with a reference case completed by the SNOPT optimizer. Results verified that our SLSQP optimizer was working properly. The solver created showed that our objective function had a difference in magnitude of 0.000019 allowing us to conclude that our solver was working as intended. However, there were several failed attempts before reaching a successful run that gave us a satisfactory …

Uncertainty Quantification Of Thermal Capacitance Calorimeter For High-Enthalpy Flows, Logan Banker, Davide Vigano

Undergraduate Research Conference at Missouri S&T

Thermal capacitance calorimeters are the standard instrument used to measure cold wall heat fluxes in high-enthalpy flows that simulates hypersonic flight conditions. These instruments play a fundamental role in the development and testing of Thermal Protection Systems for space re-entry conditions. However, despite their rugged and simple design, they are affected by large uncertainty errors. These have been estimated in literature at 15%. Despite their importance, and large errors, no proper uncertainty analysis has been performed. Uncertainty analysis is difficult due to the complex physics of the environment these calorimeters have to operate into.

Development Of A Force Perturbation Handle For Physical Interaction Research In Humans, Henry Tien, Riley Still, Yun Seong Song

Undergraduate Research Conference at Missouri S&T

The vision of developing more advanced robots that physically interact with people begins with the study of how people interact with each other. Even the simplest interactions between humans, such as shaking hands, provides tremendous challenges for current robots and minimal research has been conducted on the inner workings of these interactions. Understanding the process and mechanics behind effective and intuitive physical human-human interaction (pHHI) will yield meaningful insight into designing robots capable of assisting the elderly, operating side by side with workers, or even dancing with people. To study this process, a custom Force Perturbation Handle (FPH) was developed, …

Supersonic Wind Tunnel Modeling, Noah Cain, Davide Vigano

Undergraduate Research Conference at Missouri S&T

Supersonic wind tunnels are essential for high-speed aerodynamics research, allowing studies ranging from fundamental flow physics to the advancement of supersonic transport. This work presents a physics-based model developed for the Missouri S& T supersonic wind tunnel, a blow-down facility employing a converging-diverging nozzle to achieve high-speed flow. The model accounts for real gas effects, including Joule-Thomson phenomena, as well as predictions of pressure losses and heat transfer. Implemented in Matlab, the model's accuracy was validated through comparison with experimental measurements, demonstrating excellent agreement. This research contributes to the reliable prediction of supersonic wind tunnel performance, thus advancing the understanding …

Organic Contaminant Effects On The Mac Of Water, Jordan Hartfield

Undergraduate Research Conference at Missouri S&T

The evaporation or condensation rate of a liquid surface is directly proportional to the mass accommodation coefficient (MAC). Since the MAC is difficult, if not impossible, to experimentally measure, molecular dynamics (MD) simulations have been employed to study it. Experimental studies have shown that airborne hydrocarbon contaminants from a variety of sources can adsorb on liquid surfaces and significantly alter the surface properties. We have therefore studied the effects of organic surface contaminants, which are immiscible with water, on the MAC using equilibrium and nonequilibrium MD simulations. Our equilibrium MD simulation results show that the MAC decreases linearly with increases …

Simulating Low Gravity Particle-Laden Flow, Ryan Lewis

Student Research Symposium

No abstract provided.

Density Fluctuations Measurements In Supersonic Flows, Allie Dingfield, Davide Vigano

Undergraduate Research Conference at Missouri S&T

Turbulence in compressible flows plays a major role in a variety of aerospace applications. However, due to fluctuating thermodynamic quantities, compressible turbulence is challenging to analyze. Of these quantities, density fluctuations are of high importance due to their role in describing turbulence. A method to obtain quantitative measurements of density fluctuations has been developed using the optical technique of shadowgraph imaging. Shadowgraph imaging has frequently been used to obtain qualitative information about density gradients in fluids. However, quantitative application of these methods is much less common. The quantitative shadowgraph method presented here relates the light intensity variations in an image …

Fea Analysis On S& T Student Designed Satellite, Joseph Nguyen

Undergraduate Research Conference at Missouri S&T

The Missouri Rolla and Missouri Rolla Second Satellite (MR & MRS) is a paired satellite developed by the Missouri S& T Satellite Reseach Team (M-SAT) designed to test new technologies in support of missions involving proximity operations. The M-SAT team won first place in the Nanosatellite Competition hosted by Air Force Research Laboratory in 2015 and obtained funding to proceed with design development. The MR & MRS satellite today will undergo extensive revisions to meet new design requirements and changing technological advancements. The alterations planned for MR & MRS will not only change the structure but directly affect the thermal …

New Testing Capabilities Of The Missouri University Of Science And Technology Supersonic Wind Tunnel, Joshua Gary, Davide Vigano

Undergraduate Research Conference at Missouri S&T

The development of non-intrusive, laser-based diagnostic techniques has significantly enhanced supersonic experimental aerodynamics, enabling the measurement of many parameters in complex flow fields. Among these techniques, Tomographic Particle Image Velocimetry, capable of measuring 3 components of velocity in 3-dimensional volumes, is now available at the Aerodynamics Research Laboratory of the Missouri University of Science and Technology. To integrate this new system into the university's supersonic wind tunnel, a redesigned nozzle, test section, and diffuser have been implemented. The upgraded modular test section features 4 large ports which can be configured with windows for optical diagnostics or lead plates for model …

High-Fidelity Turbulence Modelling Of Double-Diffusive Mixing In Buoyancy Driven Flows, Sanaz Izadifar

Student Research Symposium

Double-diffusive convection is the flow caused by buoyancy gradient in a fluid, where two different scalars cause density gradients, and each scalar has significantly different diffusion rates.

Wake Characteristics Of In-Phase And Out-Phase Array Of Oscillation Airfoils, Yi-Cheng Chen

Student Research Symposium

In order to solve the hydrodynamics of a school of fish using the open-source SEM solver Nek5000, an oscillating mesh is required to simulate fish oscillations and at the same time simplify the process of mesh partitioning and satisfy the limitation of nek5000 that the mesh must be quadrilateral.

Mechanical Property Variability In Lpbf Ss316l Due To Defects Formation And Process Interruption, Tasrif Ul Anwar

Student Research Symposium

This project aims to understand the correlation between the manufacturing process, defect formation, process interruptions, and the resulting properties of components made with laser powder bed fusion techniques.