Mechanical Engineering Commons^™

Investigating The Feasibility And Stability For Modeling Acoustic Wave Scattering Using A Time-Domain Boundary Integral Equation With Impedance Boundary Condition, Michelle E. Rodio

Mathematics & Statistics Theses & Dissertations

Reducing aircraft noise is a major objective in the field of computational aeroacoustics. When designing next generation quiet and environmentally friendly aircraft, it is important to be able to accurately and efficiently predict the acoustic scattering by an aircraft body from a given noise source. Acoustic liners are an effective tool for aircraft noise reduction and are characterized by a frequency-dependent impedance. Converted into the time-domain using Fourier transforms, an impedance boundary condition can be used to simulate the acoustic wave scattering by geometric bodies treated with acoustic liners

This work considers using either an impedance or an admittance (inverse …

Turbulization Method Of Formation Of Highly Dispersed Droplets, Kh.D. Irisov, I.A. Ashirbekov, A.P. Kartoshkin, A.D. Abdazimov

Technical science and innovation

The article critically analyzes traditional methods of forming drops of defoliants and liquid chemicals. As an object of study, a sprayer with a perforated turbulator was selected, which ensures the formation of fine droplets on a short spraying torch. The degree of crushing of the working fluid, design parameters and operating modes of the proposed sprayer are investigated. Based on theoretical studies, analytical dependencies that reveal the physical properties of the sprayed liquid are analyzed, a description of the device and the principle of operation of the sprayer equipped with a perforated turbulator is given. The above analytical dependencies allowed …

Reinforcing The Strength Of Gear Shaft Teeth With High Performance, N. Turakhodjaev, Sh. Chorshanbiev, N. Sadikova, J. Egamshukurov

Technical science and innovation

This article presents the results of the research on the development of the technology of increasing the service life of the sheets in the working conditions of the casting at the Central Repairs and Mechanical Plant at the Almalyk Mining and Metallurgy Refinery (CPC). One of the factors that led to the loss of Val schisternia was the study of the appearance, rupture and dental breakdown of the working surfaces, which led to increased production costs. Analyzes have shown that thermal processing and so-called thermal processing are recommended to increase the working capacity of the plants and factories at the …

Improving The Performance Indicators Of Diesel Engines By Enhancing The Cooling System, O.O. Daminov, O.A. Khushnaev, A.I. Yangibaev, G.M. Kucharenok

Technical science and innovation

The article deals with the improvement of the performance of diesel engines by improving the cooling system. It is indicated that there is a number of problems that arise when converting an engine with spark ignition to natural gas. The increase of thermal stress of the engine is illustrated. As a result of researching of features of the parameters and characteristics of a gas-powered automobile engine and optimization of its temperature regime, a very actual scientific and practical task is determined. The engine with the spark ignition installed on the microbus working on the diesel and gas is presented. The …

Effect Of Chromium Trioxide Coating On The Thermal Performance Of Solar Thermal Collector, Èkram Hadi Alaskaree, Osamah Raad Skheel Alkhafaji, Nizar F. O. Al-Muhsen

Karbala International Journal of Modern Science

This paper compared the thermal performance of two solar collectors. The first collector is coated by a dark black absorbent solar collector, and the second one coated by the chromium trioxide. The results of the second collector show a better selectivity in terms of greater radiation absorption, and less emission compared to the first collector. At the minimum solar irradiance time, the absorbed energy is increased from 908.28J to 1221.5J, and the thermal efficiency is improved from 37.3% to 50.1% when the chromium trioxide coating is used. Besides, at the maximum solar irradiance time, the absorbed energy is increased from …

Biodiesel Production From Chicken Feather Meal And Its Performance Analysis On Diesel Engine, Venkateswarulu Tc, Indira Mikkili, Krupanidhi Srirama, Nazneen Bobby Md., John Babu Dulla, Venkata Narayana Alugunulla, Vivekananda S, Abraham Peele, Bangaraiah P

Karbala International Journal of Modern Science

Biodiesel has intrinsic lubricating properties due to the presence of long chain fatty acids, which significantly help to reduce engine wear and tear. Poultry waste as an alternative energy source could aid in reducing greenhouse gases. Biodiesel acknowledges environmental issues as it is less toxic than diesel and is biodegradable too. It is much safer to handle due to its high flash point and consequently, air quality improves dramatically. From the energy point of view, as a renewable source of energy, it helps in energy conservation and ensures regular availability for production of fuel. The chicken feather meal with moderate …

Characterization Of Reactive Ion Etch Chemistries Using Direct Write Lithography, Dylan T. Martin-Abood

Theses and Dissertations

The DoD requires a variety of COTS and number of custom microelectronics to provide important functionality to critical military systems. Photolithography and DRIE are two techniques commonly used in the development of deep anisotropic features for the fabrication and modification of microelectronics and MEMS. However, standard photolithography techniques are ineffective for unique substrate geometries and DRIE processes require a chemical passivation step only applicable to Si substrates. This work confirmed the capability of RIE using DWL to perform deep, highly selective, anisotropic etching on elevated, non-circular substrates.

A Wirelessly Controlled Smart Bandage With 3d-Printed Miniaturized Needle Arrays, Hossein Derakhshandeh, Fariba Aghabaglou, Alec Mccarthy, Azadeh Mostafavi, Chris Wiseman, Zack Bonick, Ian Ghanavati, Seth Harris, Craig Kreikemeier-Bower, Seyed Masoud Moosavi Basri, Jordan Rosenbohm, Ruiguo Yang, Pooria Mostafalu, Dennis Orgill, Ali Tamayol

Department of Mechanical and Materials Engineering: Faculty Publications

PUBLIC ACCESS

Results Of Improvement Of The Technological Process Of Sorting Of Draged Seeds, R.K. Djamolov, E.T. Maksudov, K. Djamolov

Irrigation and Melioration

The article presents the results of experiments conducted to justify the parameters of the seed selection unit to improve the process of sorting seeds. The experiments were carried out by changing the angle of inclination of the seed tray to the horizontal plane from α = 390 to α = 540 and the radius of the lower part of the tray in the aisle R = 140-180 mm. The experimental results show that the bottom of the tray, made in the form of a semicircle, allows the seeds to move up the pipe when the seeds fall from the tray …

Novel Methods For Composites Recycling Via Pyrolysis, Matt Jacobs

Undergraduate Honors Theses

Composites are unique materials in many respects. When fabric woven from carbon fibers is joined with a thermoset resin in a controlled environment, it results in a very strong material, especially evaluated on a pound-for-pound basis against metals and ceramics. One aspect of this construction that provides great strength lies in the fiber-matrix adhesion which facilitates load transfer to the reinforcement of the composite. This fiber-matrix adhesion is promoted by the polarity of the usual thermoset matrices, and properly designed sizing materials coating the fibers. It’s a two-edged sword, though. Although the resin and the fibers are quite strong together, …

Characterization Of Nanorod Lmo Li-Ion Battery Performance And Microstructure Degradation, Austin Gabhart, Hernando Gonzalez Malabet

Research Horizons Day Posters

No abstract provided.

Design Of An Affordable Rotating Drum Electrospinner For Classroom Education, Peder Solberg

The Journal of Undergraduate Research

Electrospinning is a technology used to generate small fibers down to nano-scale size. This method of fiber creation has been around for many years. However, in recent years electrospinning has found increased applications, especially in the area of tissue engineering due to its ability to create fibers with properties similar to the extracellular matrix in tissue. An electrospinning platform can illustrate concepts of engineering, electro-mechanical system design, manufacturing, and biomedical applications in one single package. Hence, it provides an excellent opportunity to integrate into secondary (middle and high school) and post-secondary (undergraduate) technology education.

Furthermore, just as integration of 3D …

Proper Orthogonal Decomposition And Recurrence Map For The Identification Of Spatial–Temporal Patterns In A Low-Re Wake Downstream Of Two Cylinders, Meihua Zhang, Zhongquan Charlie Zheng, Huixuan Wu

Mechanical and Aerospace Engineering Faculty Publications

Flow decomposition methods provide systematic ways to extract the flow modes, which can be regarded as the spatial distribution of a coherent structure. They have been successfully used in the study of wake, boundary layer, and mixing. However, real flow structures also possess complex temporal patterns that can hardly be captured using the spatial modes obtained in the decomposition. In order to analyze the temporal variation of coherent structures in a complex flow field, this paper studies the recurrence in phase space to identify the pattern and classify the evolution of the flow modes. The recurrence pattern depends on the …

Review Of Living Learning Communities And Their Impact On First Year Engineering College Students, Samantha Schauer, Krishna Pakala, Kim M.B. Tucker

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Traditionally, first-year college students do not have a community of like-minded peers with whom they are able to learn. Adding to first-year engineering college students’ (FYECS) struggles is the fact that many students do not have a mentor in their related field and are unable to start building their professional repertoire, network, and/or practical skills. Living Learning Communities (LLC) can offer a platform for postsecondary institutions to increase recruitment, engagement, and sense of belonging for students who live in an LLC. LLCs have been described in the literature as themed living and learning communities where students take a common course(s), …

Comprehensive Second-Order Adjoint Sensitivity Analysis Methodology (2nd-Asam) Applied To A Subcritical Experimental Reactor Physics Benchmark: Iv. Effects Of Imprecisely Known Source Parameters, Ruixian Fang, Dan Gabriel Cacuci

Faculty Publications

By applying the Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) to the polyethylene-reflected plutonium (PERP) benchmark, this work presents results for the first- and second-order sensitivities of this benchmark’s leakage response with respect to the spontaneous fission source parameters. The numerical results obtained for these sensitivities indicate that the 1st-order relative sensitivity of the leakage response to the source parameters for the two fissionable isotopes in the benchmark are all positive, signifying that an increase in the source parameters will cause an increase in the total neutron leakage from the PERP sphere. The 1st- and 2nd-order relative sensitivities with respect to …

Investigation Study Of A Novel Oscillating Thermo-Magneto-Electric Generator, Abdulrahman Mohammed Homadi

Theses and Dissertations

In this dissertation, we present a unique system working as a generator that takes the advantage of waste heat dissipation from an application to generate electricity by induction. This system can be called a thermo-magneto-electric generator (TMEG), because it deals with a heat source, heat sink, and magnetic field generated by a permanent magnet (PM) and works to generate voltage by induction. The magnetic energy is the resource power of this system due to the existence of the magnetic material (ferromagnetic), and the reason of the movement is the change in the amount of magnetic energy repeated by the change …

Porous Silica Nanotube Thin Films As Thermally Insulating Barrier Coatings, Derric B. Syme, Jason M. Lund, Brian D. Jensen, Robert C. Davis, Richard R. Vanfleet, Brian D. Iverson

Faculty Publications

The fabrication and examination of a porous silica thin film, potentially for use as an insulating thin film, were investigated. A vertically aligned carbon nanotube (CNT) forest, created by chemical vapor deposition (CVD), was used as scaffolding to construct the porous film. Silicon was deposited on the CNT forest using low-pressure CVD (LPCVD) and then oxidized to remove the CNTs and convert the silicon to silica for electrical or thermal passivation (e.g., thermal barrier). Thermal conductivity was determined using a 1D heat-transfer analysis that equated radiative heat loss in a vacuum with conduction through the substrate and thin film stack. …

Examining Career And Technical Education Practitioner Preparation And Professional Development Needs, Shane Wilson Lange

Theses and Dissertations

This quantitative study was used to investigate Illinois automotive educator professional development needs and to identify the demographic landscape of Illinois secondary and post-secondary automotive teachers. The study should bring a greater understanding of what automotive teachers feel they need to learn in order to continue as successful educators. A modified Borich (1980) needs assessment model was used to identify the perceived importance and ability levels for 32 professional competencies. Mean Weighted Discrepancy Scores (MWDS) were calculated using the importance and ability scores in order to report the professional development need. The administered survey was also utilized to examine their …

The Use Of Succinonitrile As An Electrolyte Additive For Composite-Fiber Membranes In Lithium-Ion Batteries, Jahaziel Villarreal, Roberto Orrostieta Chavez, Sujay A. Chopade, Timothy P. Lodge, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

In the present work, the effect of temperature and additives on the ionic conductivity of mixed organic/ionic liquid electrolytes (MOILEs) was investigated by conducting galvanostatic charge/discharge and ionic conductivity experiments. The mixed electrolyte is based on the ionic liquid (IL) (EMI/TFSI/LiTFSI) and organic solvents EC/DMC (1:1 v/v). The effect of electrolyte type on the electrochemical performance of a LiCoO₂ cathode and a SnO₂/C composite anode in lithium anode (or cathode) half-cells was also investigated. The results demonstrated that the addition of 5 wt.% succinonitrile (SN) resulted in enhanced ionic conductivity of a 60% EMI-TFSI 40% EC/DMC MOILE …

Three-Phase Hydrodynamic Simulation And Experimental Validation Of An Upflow Anaerobic Sludge Blanket Reactor, Camila D' Bastiani, Jéferson Luis Alba, Gabriel Tomazzoni Mazzarotto, Severino Rodrigues De Farias Neto, Anthony Reynolds, David Kennedy, Lademir Luiz Beal

Articles

This research focuses on performing multiphase solid/liquid/gas CFD simulations of a UASB reactor in order to obtain a validated model that provides a clearer understanding of the hydrodynamic behaviour of the three phases in UASB reactors. Eulerian–Eulerian, laminar, three-dimensional, multiphase simulations are carried out using Fluent 16.2. The liquid phase velocity and flow profile are validated through PIV experiments. A liquid mean velocity difference of 8.45% is found between the experimental and numerical results, thus validating the CFD model. Shadowgraphy is applied successfully to validate the biogas phase velocity and bubble size. Based on the hydrodynamic analysis results, the reactor …

Geometric Iteration Of A Knee Prosthetic And Static Stress-Bearing Capacity, Alexander Wheeler

Honors Program: Senior Projects (Public)

The purpose of this study was to improve a prosthetic knee model in terms of size, weight, and biocompatibility. Several tests were run to determine its effectiveness in supporting static and quasistatic loads. The positions in which these tests were run include static upright standing, static one-knee 90 degree kneeling, static squatting at maximum flexion, and quasistatic midstride. These simulations were conducted to find areas of high stress and strain. These patterns were used to determine the maximum body weight a physical prosthetic could support. The material used to create the prosthetic was changed from AISI 316 stainless steel to …

Dartmouth Formula Racing: Full Electric Battery System Design, Matt Gardner, Jacob Hagler, Ruthie Nordhoff, Otto Salmi

ENGS 89/90 Reports

Dartmouth Formula Racing (DFR) lacked an electrical energy storage system that was Formula Hybrid rules-compliant, optimized for FH events, safe, reliable, and integrated with the rest of their vehicle. Additionally, the team lacked the academic and professional resources required to bring a thorough, analytical approach to the design, testing, and documentation of the new storage system. Our team designed and built a Lithium-Ion battery pack (accumulator) containing energy storage, active cooling, battery management and temperature monitoring systems, and control circuitry compatible with DFR’s vehicle. Collaboration throughout design, fabrication, assembly and testing processes ensured effective knowledge transfer to the DFR team.

Tribological And Thermal Transport Of Ag-Vegetable Nanofluids Prepared By Laser Ablation, Jaime Taha-Tijerina, Sadasivan Shaji, Sreed Sharma Kanakkillam, Maria Isabel Mendivil Palma, Karla Aviña

Informatics and Engineering Systems Faculty Publications

Lubricants and fluids are critical for metal-mechanic manufacturing operations as they reduce the friction and wear of tooling and components, and serve as coolants to dissipate the heat generated in these operations. The proper application of these materials improves machine operative life and tooling, and decreases cost, energy, and time consumption for maintenance, damage, repairs, or the need to exchange pieces/components within the machinery. Natural or vegetable-based lubricants have emerged as a substitute for mineral oils, which harm the environment due to their low biodegradability and have negative effects on human health (e.g., causing skin/respiratory diseases). Thus, finding biocompatible and …

A Novel Self-Healing System: Towards A Sustainable Porous Asphalt, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen

Articles

Self-healing asphalt, aimed to produce a sustainable asphalt pavement using green technology, has been studied in the past two decades. Technologies including encapsulated rejuvenator and induction heating have been proposed, demonstrated in the laboratory, and gradually evaluated in field application. This paper looks into the synergy effect of the above two technologies, where induction heating serves as the asphalt damage repair mechanism, requiring just 2 min heating time and encapsulated rejuvenator will replenish (rejuvenate) aged asphalt binder and reinstate bitumen’s healing ability. Moreover, the increased temperature from induction heating could in turn accelerate the diffusion process of rejuvenator into aged …

Energy Saving Issues In Pumping Units, A.I. Anarbaev, D.B. Kodirov, R.A. Zakhidov, B. Usmanov

Irrigation and Melioration

The article presents the issues of energy saving, which are becoming increasingly relevant due to the constant increase in tariffs and the introduction of the demands on energy efficiency and energy conversation. To save energy at pumping units, the characteristics of controlling the electric drive of pumping stations with frequency-controlled control are considered. For adequate adjustment by the technological process of water movement and power supply, corresponding analytical dependencies are obtained. An analysis of the physical expressions of water pumping processes allowed us to determine energy-saving modes of operation and technologies for improving the efficiency of equipment.

Importance Of Creating A System Of Land And Cadastral Data For Subjects Of Agriculture, К. Rakhmonov, M.O. Abdurakhimova

Irrigation and Melioration

A separate model and model were developed for compiling cadastral maps used by the authors for agricultural organizations. The model is intended for enterprises operating in the Tashkent region. The article is based on the scientific and methodological order and the system of destruction of irrigated lands. Based on the experience of leading foreign countries in this area, the possibilities of introducing modern electronic computers in Uzbekistan are presented. The procedure for converting data into a specific algorithm is recommended for the formation of a system of land cadastral data in agricultural entities. It is necessary to create an information …

Apple Orchard Drip Irrigation Conditions Of The Tashkent Region Of Uzbekistan, Sardor Gulyamov, Bakir Serikbaev, Anvar Sherov

Irrigation and Melioration

The article presents the results of many years of theoretical experimental field research on drip irrigation of the apple orchard of the Golden variety in the conditions of the Tashkent region. Based on the analysis of climatic, soil, hydrogeological, geological, hydrological and economic conditions of the experimental plot, as well as biological features of the garden, the values of total water consumption, water consumption deficit, irrigation, irrigation rate and the number of irrigation by the bioclimatic method are determined.

Calculation Of The Placement Of Vertical Drainage Wells Near An Open Water Source In The Conditions Of Waterlogging Of Built-Up Areas, B.K. Saliev

Irrigation and Melioration

The article discusses the methodology for calculating the intercepting drainage well that reveals the upper layer of the multilayer horizon, and presents analytical dependencies based on the hydrodynamic theory and formulas for approximate calculation of the location of the axial line of the blocking drainage between the source of flooding and the protected built-up area from flooding. In particular, mathematical methods have been improved to solve the forecast problems of flooding in conditions of different pressure, based on the relationship between the depressions and the incoming flow of pressure water into the drainage well. The presence of underground pressure water …

Multisector Water Consumption Database: Surkhandarya Region Of The Republic Of Uzbekistan, М. Ikramova, С. Batishev, О. Ikramov, H. Kabilov, D. Nazaraliev, А. Khodjiev, I. Akhmedkhodjaeva

Irrigation and Melioration

The available water resources in the country are used by the different sectors of economy as industry, agriculture, energy, communal service and etc. In this case the water distribution within the river basin requires perfect information service and data exchange facilities. In the paper the developed unified multi-sector on-line database is presented aimed to monitor the water distribution among sectors of economy, database structure, and data exchange tools. The software works at operative mood, allows evaluating the combined water use efficiency by water users.

Field Research Methods And Some Results For Distribution Of Suspended Sediment In Flow Constrained By Transverse Dams, M.R. Bakiev, K.T. Yakubov, O.M. Matkarimov, Z.B. Dovlatov

Irrigation and Melioration

The article presents methods for determining the main parameters of flow of medium hydraulic size sediment, turbidity, sampling methods in field and the instruments used for sampling, methods of processing the samples in laboratory. Methods for setting sections and gage points and conducting field and laboratory research have been developed for flow deformed by blank and through flow transverse dams, water surface longitudinal and transverse slope takes place in the flow constrained by transverse dams, changes in suspended sediment distribution occur inversely. Location of sections for sampling is determined in the article: in the headrace –beyond dam influence zone, maximal …