Mechanical Engineering Commons^™

Change In Level Water In Pumping-Plant Intake, R.R. Ergashev, B.T. Xolbutayev

Irrigation and Melioration

A decrease in the water level in the pump chamber of the pumping stations leads to the formation of whirlpools in front of the suction pipes. As a result of air intake, the pump unit operates in cavitation mode and their intensive wear occurs. As the data obtained from the Karshi machine channel show, mainly a decrease in design water levels in the downstream waters is observed at the first pumping station. Depending on the number of simultaneously operating pumping units, the minimum water level in the head pumping station should be from 4.5 m to 5.7 m. The received …

Modeling The Impact Of Changes In The Ground Water Level On The Stability Of Agricultural Landscapes Using Gis, A.M. Arifjanov, L.N. Samiev, F.K. Babajanov, G.M. Xamdamova, Sh.N. Yusupov

Irrigation and Melioration

The article presents modern GIS methods for determining the stability of changes in irrigated areas and the depth of the ground water level.the most correct solutions are given in modeling this process. To distinguish agricultural landscapes, the classification of agricultural acreage in the lower part of the Amu Darya river region was made using 16-day periodic rasters 2017 of 2018 and the NDIS MOD13Q1 sensor of agricultural acreage, type NDVI. The annual change in the level of underground water in relation to the state of rivers and channels is analyzed. A steady change in agricultural acreage on the right Bank …

Determination And Assessment Of The Spatio-Temporal Changing Dynamics In The Groundwater Level And Mineralization In Irrigated Areas Under Climate Change (As An Example Of Syrdarya Province), S. Khasanov, S. Adilov, R. Kulmatov

Irrigation and Melioration

In the irrigated lands of the Aral Sea Basin, salinization processes are taking place as a result of rising groundwater levels and increasing its mineralization due to the unsustainable use of water and land resources. This, in turn, leads to the withdrawing of arable land and a decrease in crop yields. This is especially the case in the irrigated areas of the lower reaches of the Amudarya and Syrdarya rivers, located in Uzbekistan, southern Kazakhstan, and Turkmenistan. This research was aimed to learn and evaluate the long-term changing behavior of groundwater level and mineralization in the irrigated areas of the …

Increasing The Efficiency Of Water Distribution Management When Operating Pumping Stations Of The Irrigation System, O.Y. Glovatsky, R.R. Ergashev, B. Hamdamov, N.M. Ismailov, B.T. Kholbutaev

Irrigation and Melioration

The article is to control the parameters of the unsteady movement of water in the canals and the pumping station, which ensure the maintenance of the specified operating modes of the pumping stations under non-stationary conditions. To achieve this goal, it is necessary to solve the problems of coordinating the operating modes of the units of the head pumping station (PS) with the operating modes of the partitioning structures in the conditions of emptying and filling the ponds of the main canal with water. The article discusses the implementation of the method of water distribution control on the mathematical model …

Analysis Of Theoretical And Natural Field Studies Of Reservoir Silling, A.M. Arifjanov, F. Gapparov, T.U. Apakhujayeva, S.N. Xoshimov

Irrigation and Melioration

The article developed a mathematical model of the processes of siltation of reservoirs, taking into account the energy state of the flow, and proposed a calculation method. In the process of siltation of the reservoir, the dependence of the volume on the change in the water level in the reservoir was estimated. On the basis of studies carried out in full-scale field conditions, the recommended calculation method is comparatively evaluated and analyzed. Field studies were carried out in the Chimkurgan, Tashkent and Yuzhno-Surkhan reservoirs. A relationship is obtained that expresses the dependence of the relative volume of siltation of the …

Planed Dimension Of Flow Deformed By A Single Dam That Is Impermeable To Water From The Body, M.R. Bakiev, K.T. Yakubov, I.J. Asamatdinov

Irrigation and Melioration

Coastal erosion is a type of water erosion that causes significant damage to the national economy each year: leaching of overland coastal crops, failure of protective dams, destruction of irrigation canals, dilapidated buildings and structures, among others. To combat leaching, cross-dams are used which are waterproof and water-permeable. The aim of this work was to develop a method for calculating the planned dimension of compressed flow with a transverse dam, which included comparing the lengths of the upper and lower tilt zones, the boundaries of individual zones and the results of research in the laboratory and in nature. According to …

Research Of Energy Indicators Of Electric Drives With Frequency Converters (Frequency Converters) On The Operating Equipment Of Cotton Cleaning Plants, A.J. Isakov, B.K. Tukhtamishev, J.N. Tolipov

Irrigation and Melioration

The article deals with the theoretical and practical substantiation of the replacement of an unregulated electric drive of the main technological equipment of cotton refineries with a frequency-controlled electric drive. The influence of a change in the load on the motor shaft on the main parameters of the steady state is considered. In an asynchronous motor, with an increase in the load, slip increases to such a value at which the torque of the motor balances the increased moment of resistance. Considering that when the stator slip resistance is less than the critical one is a small fraction of the …

Stabilization Of Discharge Processes Involved In Electrical Fields Of Electrostatic Precipitators, Sh.M. Muzafarov, B.N. Erkinov, A.I. Pardaev, V.E. Baliskiy, B.К. Tаgaev

Irrigation and Melioration

The article provides information on achievements in the field of electrical gas cleaning. A critical analysis of the principle of operation of the electrostatic precipitators developed and currently in operation is carried out. The possibility of increasing the efficiency of electrical gas cleaning using unipolar voltage pulses is analyzed. A theoretical analysis of the processes in the discharge gap was carried out using the existing theory of electric discharges in gases. Based on the analysis of the data, the discharge mechanism is established in a sharply inhomogeneous electric field at a pulsed voltage. It is established that when using voltage …

Determination Of The Rational Values Of The Parameters Of The Disc Rollers Of The Combined Unit, A.K. Igamberdiev, D.K. Muqimova

Irrigation and Melioration

In our country, repeated crops are sown in newly plowed lands. In such conditions, the use of combined units that perform several technological operations simultaneously in one pass is considered effective. However, due to the inadequacy and validity of the parameters of the working bodies for the quality of pre-sowing tillage in newly plowed lands, there is an increase in the number of passes, fuel consumption, loss of soil moisture and other costs and, as a result, the possibility of timely sowing and friendly germination of repeated crops is reduced . The rational parameters of the new design of disk …

Autonomous Photovoltaic System For Year-Round Guarantee Supply Of Electricity To Rural Facilities, M.N. Tursunov, Х. Sabirov, U.R. Kholov, Т.Z. Аkhtamov

Irrigation and Melioration

The article discusses the physical and technical features of the experimental results of studying the parameters of an autonomous photovoltaic station (AFES) with a power of 2600 W designed and manufactured on the basis of 16 photovoltaic batteries made of polycrystalline silicon with an efficiency of 15.6 %. It is shown that an autonomous photovoltaic efficiently and reliably provides electric energy a lighting system for car parking in the winter season (January and February) and it is planned to lift water from a well with a depth of 70-80 m for irrigation and maintenance of the Heliopoligon from April 2020. …

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 …

Sound Vortex Diffraction Via Topological Charge In Phase Gradient Metagratings, Yangyang Fu, Chen Shen, Xiaohui Zhu, Junfei Li, Youwen Liu, Steven A. Crummer

Henry M. Rowan College of Engineering Departmental Research

Wave fields with orbital angular momentum (OAM) have been widely investigated in metasurfaces. By engineering acoustic metasurfaces with phase gradient elements, phase twisting is commonly used to obtain acoustic OAM. However, it has limited ability to manipulate sound vortices, and a more powerful mechanism for sound vortex manipulation is strongly desired. Here, we propose the diffraction mechanism to manipulate sound vortices in a cylindrical waveguide with phase gradient metagratings (PGMs). A sound vortex diffraction law is theoretically revealed based on the generalized conservation principle of topological charge. This diffraction law can explain and predict the complicated diffraction phenomena of sound …

Method Of Joints: Theory And Practice Of Designing, Building, And Testing Trusses, Andrew J. Hughes, Chris Merrill

Educational Leadership & Technology Faculty Publications

The authors of this article, like many of us, are proponents of engineering education but are also proponents of shop skills, craftsmanship, technological literacy, and the tacit knowledge and skills developed through applying sound theories during practical hands-on learning. The authors believe that engineering is an important aspect of our discipline, but so are the application of thinking, tool skills, measurement, geometric construction, manufacturing, instrumentation, testing and analysis, mathematical and scientific theories, and many other hands-on, minds-on skillsets that all need to maintain association with our discipline. As the authors are proponents for engineering education that is done well, they …

A Mathematical Framework For Estimating Risk Of Airborne Transmission Of Covid-19 With Application To Face Mask Use And Social Distancing, Rajat Mittal, Charles Meneveau, Wen Wu

Faculty and Student Publications

© 2020 Author(s). A mathematical model for estimating the risk of airborne transmission of a respiratory infection such as COVID-19 is presented. The model employs basic concepts from fluid dynamics and incorporates the known scope of factors involved in the airborne transmission of such diseases. Simplicity in the mathematical form of the model is by design so that it can serve not only as a common basis for scientific inquiry across disciplinary boundaries but it can also be understandable by a broad audience outside science and academia. The caveats and limitations of the model are discussed in detail. The model …

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 …

Modeling, Simulation, And Testing Of Sweeping Convection, Amir Kiaee

Mechanical Engineering Research Theses and Dissertations

In this study, the new convection heat transfer concept of sweeping convection, using large particles flowing with a fluid in a channel, is considered. This novel concept is inspired by the gas exchange process in alveolar capillaries, where red blood cells (RBCs) flow with blood plasma, yielding very high gas transfer efficiency. An important characteristic of alveolar capillary blood flow, believed to be related to the high efficiency of the lungs, is the snug fitting of the RBCs into the capillaries. This tight fitting sets the RBCs (particles) acting like pistons as they flow downstream with the plasma (fluid), facilitating …

Open Source High-Temperature Reprap For 3-D Printing Heat-Sterilizable Ppe And Other Applications, Noah G. Skrzypczak, Nagendra G. Tanikella, Joshua M. Pearce

Michigan Tech Publications, Part 1

Thermal sterilization is generally avoided for 3-D printed components because of the relatively low deformation temperatures for common thermoplastics used for material extrusion-based additive manufacturing. 3-D printing materials required for high-temperature heat sterilizable components for COVID-19 and other applications demands 3-D printers with heated beds, hot ends that can reach higher temperatures than polytetrafluoroethylene (PTFE) hot ends and heated chambers to avoid part warping and delamination. There are several high temperature printers on the market, but their high costs make them inaccessible for full home-based distributed manufacturing required during pandemic lockdowns. To allow for all these requirements to be met …

Local Eigenvalue Modification Procedure For Real-Time Model Updating Of Structures Experiencing High-Rate Dynamic Events, Claire Rae Drnek

Theses and Dissertations

Estimating the state of structures that experience high-rate dynamics requires real-time model updating capabilities. In this work, high-rate dynamic events are characterized by 1) large uncertainties in the external loads, 2) high levels of non-stationarities and heavy disturbances, and 3) unmodeled dynamics generated from changes in system configurations. To achieve real-time model updating, an algorithm must circumvent any pre-calculations and be able to update the structure’s state on the timescale of 2 ms or less. This can be accomplished in one of two ways: either by creating a simplified model of a complex structure or by simplifying the calculations needed …

Effect Of Additional Weight On Human Squat Exercise Stability: Ground Reaction Forces And Centers Of Pressure, Jose Galarza, Dumitru Carantu

Mechanical Engineering Faculty Publications

The main focus of this work is to investigate the effect of weight on the stability of human squat exercise. The squat exercise is a common daily activity. Experiments are conducted using one human subject. A VICON motion analysis system integrated with Force Plates is utilized for these experiments. An experimental protocol is developed and followed. This work analyzes the time series of the normal component of the ground reaction forces and each coordinate of the center of pressure. These time series are used to estimate the Lyapunov Exponents using Rosenstein method. MATLAB software package is used for this investigation. …

Anomalous Growth Of Al8Mo3 Phase During Interdiffusion And Reaction Between Al And Mo, Abhishek Mehta, Le Zhou, Dennis D. Keiser Jr., Yongho Sohn

Mechanical Engineering Faculty Research and Publications

No abstract provided.

Finite Element Analysis Investigation Of Hybrid Thin-Ply Composites For Improved Performance Of Aerospace Structures, Alana M. Zahn

Mechanical & Aerospace Engineering Theses & Dissertations

Commercial and private aircraft have a need for strong yet light materials in order to have the most ideal performance possible. This study looks at the use of thin-ply composite materials to improve the performance of aircraft structures by means of weight savings and/or strength increase when compared to laminates that are composed of exclusively standard-ply materials. In order to perform an investigation based solely on finite element analysis, validation efforts were performed using test data from open hole tension, open hole compression, notched tension, and notched compression specimens. Once the models were validated sufficiently, the same modeling practices were …

Human-Automation Interaction Testbed For Evaluating User Control Methods And Training, Sarah M. O'Meara

Link Foundation Modeling, Simulation and Training Fellowship Reports

In a complex work environment, an operational challenge may be controlling the multitude of independent objects that are required for a manual task and/or object manipulation, such as experienced by astronauts, surgeons, underwater operations, manufacturing etc. One possible option is the enhancement of the person’s capabilities through a robotic supernumerary limb (Figure 1). The idea has already been implemented in a limited application, where the United States Army Research Laboratory developed a passive limb to aid soldiers in weapon carrying and stabilization[1]. Researchers are also creating supernumerary robots. Parietti, et al. [2] designed the Supernumerary Robotics Limbs to address aircraft …

Agent-Based Modelling Of Values: The Case Of Value Sensitive Design For Refugee Logistics, Christine Boshuijzen-Van Burken, Ross J. Gore, Frank Dignum, Lamber Royakkers, Phillip Wozny, F. Leron Shults

VMASC Publications

We have used value sensitive design as a method to develop an agent-based model of values in humanitarian logistics for refugees. Schwartz’s theory of universal values is implemented in the model in such a way that agents can make value trade-offs, which are operationalized into a measure of refugee wellbeing and a measure of public opinion about how the refugee logistics is being handled. By trying out different ‘value scenarios’, stakeholders who are responsible for, or involved in refugee logistics can have insights into the effects of various value choices. The model is visualized and made usable as a platform …

Steady-State And Transient Study Of Flow Boiling In Microchannels With Microgrooves/Micronozzles, Congcong Ren

Theses and Dissertations

Microchannel flow boiling is one of the most desired cooling solutions for high power electronics. Owing to the high latent heat of vaporization, high heat fluxes can be achieved through phase-change heat transfer. However, the enhancements of (critical heat flux) CHF and heat transfer coefficient (HTC) are usually inhibited by the transitional flow patterns, which highly influence the liquid rewetting. In the past two decades, many techniques have been explored to enhance the liquid rewetting in microscale.

In this dissertation, four parallel micro-grooves fabricated on the bottom of five microchannels (W=200 μm, H=250 μm, L=10 mm) were designed to promote …

Ultrasonic Nondestructive Evaluation Using Non-Contact Air-Coupled Lamb Waves, Wenfeng Xiao

Theses and Dissertations

Ultrasonic Lamb waves have been proved as an effective nondestructive evaluation (NDE) method due to their ability to propagate a long distance with less energy loss as well as their sensitivity to various defects on the surface or inside the structure. However, there are still challenges towards using them as a rapid inspection method for complex structural geometries, various damage types, and harsh environments, such as efficiency in Lamb wave actuation and sensing, understanding of the complicated multi-modal Lamb wave propagation, and robust detection algorithms for damage quantification and evaluation. To address these challenges, this dissertation focuses on developing a …

Artificial Intelligence Approaches For Structural Health Monitoring Of Aerospace Structures, Kimberly A. Cardillo

Theses and Dissertations

Structural health monitoring (SHM) and non-destructive evaluation (NDE) have been a significant research topic to help with damage detection in aerospace structures. SHM and NDE techniques are based on extracting damage sensitive features to determine the criticality of damage and lifetime of a structure. Acoustic emission (AE) signal detection is an important technique in SHM and NDE especially for fatigue crack growth. AE signals for thin aerospace structures consist of ultrasonic guided Lamb waves that propagate through the structure. This thesis focuses on AE signal repeatability, load at which AE signals occur, feature extraction, artificial intelligence and electro-mechanical impedance of …

Modeling Airflows And Voc Source Strengths For An Occupied School, Brett Stinson

University Honors Theses

Volatile organic compounds (VOCs) are a group of air pollutants that can adversely impact human health, engage in chemistry indoors, and meaningfully degrade indoor and outdoor urban air quality. While extensive research with regard to VOC emission rates from indoor sources has been conducted, it was not until recently that this work began to focus on characterizing emissions from humans and human activity in depth. As buildings are constructed to be increasingly airtight, and the materials utilized are chosen to reduce VOC emissions, it follows that human contributions are poised to become increasingly important indoor sources of VOCs. Utilizing data …

Exploration And Evaluation Of Novel Cathode Materials For Intermediate-To-Low Temperature Solid Oxide Fuel Cells, Chunyang Yang

Theses and Dissertations

Solid oxide fuel cells (SOFCs) have attracted considerable attentions due to its high conversion efficiency, fuel flexibility, and clean nature. However, the high cost and poor long-term stability induced by the high operating temperature (> 800 °C) of the conventional SOFCs hinder the further application. Therefore, lowering operating temperature to intermediate temperature range (IT, 650-800 °C) or even low temperature range (LT, 400-650 °C) is of practical importance for realizing SOFCs’ full commercial potential. Nevertheless, due to the large activation energy associated with oxygen reduction reaction (ORR), cathode polarization resistance becomes the dominate loss limiting SOFCs performance as operating temperature …

Autonomous Drone-Based Sensor Package Deployment To The Underside Of Structures, Sabrina Rose Carroll

Theses and Dissertations

The objective of this project is to design, develop and experimentally test an Unmanned Aircraft System (UAS, commonly known as a drone) for the deployment of sensor packages to the underside of structures. This work begins with an in-depth review of existing automation techniques for various drone applications focusing on applications requiring interaction with the environment. Further reviewed is the impact of structures above the UAS during flight on the behavior of the aircraft.

Considering these topics, the development of a custom drone is presented to address the difficulties of delivering a package to the underside of a structure. Starting …

Lamb Wave Nondestructive Evaluation And Imaging On Plate-Like Structures, Zhaoyun Ma

Theses and Dissertations

Structure components are designed with a certain service life and damage may occur, or they may come with manufacture defects. Such damage and defects may lead to structural failure if not detected in time. To ensure the structural safety and prevent catastrophic failure, effective inspection is critical for in-time maintenance. Nondestructive evaluation (NDE) and structural health monitoring (SHM) have been widely applied for damage inspection and evaluation in various industries due to their noninvasive nature. Lamb wave based NDE/SHM has become the most popular ultrasonic methods that has been proved effective in different engineering applications that can be used to …