Engineering Commons^™

Anion Exchange And Bipolar Membranes For Electrochemical Energy Conversion And Storage, Zhongyang Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Anion exchange and bipolar membrane fuel cells generate electrical energy directly from chemical fuels and have attracted considerable interests as alternate power sources for large market applications, such as transportation (hydrogen fuel cells) and unmanned vehicles (sodium borohydride fuel cells). Anion exchange membrane (AEM), generally composed of a polymer with covalently tethered ionic groups, is the central component of the fuel cell serving as the electrolyte, conducting hydroxide ions from cathode to anode, where fast ionic conduction is directly related to power output. However, AEMs currently used in fuel cells (H2 fuel cells and sodium borohydride fuel cells) exhibit ion …

City Of New Smyrna Beach Solar Feasibility Assessment, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

At the request of the City of New Smyrna Beach, the Florida Solar Energy Center (FSEC) assessed rooftop solar and building energy efficiency improvement potential for 17 city-owned facilities. The intent has been to assist City leaders in identifying opportunities to reduce the City's overall electricity consumption and increase its use of renewable energy.

The FSEC team conducted Level 1 energy audit activities and site assessments including:

On-site assessment

• Solar feasibility measurements and characterization including orientation, roof shading (adjacent structures, encroaching trees, etc.), available roof area, system output, annualized savings
• HVAC characterization
• Lighting survey
• Occupancy density, schedule, thermostat settings

Post …

Expanding The Palette: Synthesizing Microencapsulated Organic Phase Change Materials In Metallic Matrices For Transient Thermal Applications, Melissa Kate Mccann

McKelvey School of Engineering Graduate Student Theses & Dissertations

As the demand for smaller and faster electronics increases, it becomes increasingly challenging to effectively manage the generated heat without hindering device performance in applications whose thermal profiles are dominated by pulsed thermal loads. Heat propagation in a system can be characterized by steady or transient state heat transfer. In steady state, the temperature at any particular point remains constant after thermal equilibrium is reached. In a transient state, the temperature within a system varies over time. The changing parameters and time dependency associated with a transient regime make heat transfer calculations far more complex than in a steady state. …

Ph-Sensitive Oxygen Release Microspheres To Enhance Cell Survival In Ischemic Condition, Zhongting Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Ischemic diseases such as myocardial infarction, stroke and limb ischemia are severe cardiovascular diseases with high rate of death and millions of people suffered from these diseases. Under ischemic environment, cells die due to deficient supply of nutrient and oxygen. To regenerate ischemic tissues, stem cell therapy is a promising approach because stem cells can differentiate into cells necessary for the regeneration. However, stem cell therapy has limitations. For example, few cells can survive under harsh ischemic environment. To enhance stem cells survival, implantation of oxygen release microspheres to sustained supply cells with oxygen represents an effective strategy. Previously, our …

Molecular Dynamics Studies Of Thin-Film Evaporation: The Effect Of Graphene-Coated Silicon On Water Evaporation Behavior, Rui Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Conventional single-phase air or liquid cooling methods are insufficient to dissipate the high heat flux of next-generation electronic systems. Thin-film evaporation is one of the most promising solutions, because it takes advantage of the large amount of latent heat in the phase change process. It is important to understand the relationship between interfacial thermal resistance, surface wettability, and thin-film evaporation behavior. In this study, non-equilibrium molecular dynamics simulations are used to study mass and heat transfer in thin-film evaporation of water on a silicon substrate, and equilibrium molecular dynamics simulations are used to study the surface wettability by measuring contact …

Retrofit Of Corroded Corrugated Metal Culverts Using Gfrp Slip-Liner, Rahulreddy Chennareddy

Civil Engineering ETDs

Culverts are water conveyance structures, typically used to allow water flow and maintain a balance between the flow streams without interrupting structures such as highways and bridges. Corrugated metal pipes (CMPs) have been used as culverts in North America since the 1950s because of their low cost and simple construction method. Today, the corrosion of CMPs is a major problem faced by all U.S. Departments of Transportation. There is an urgent need to provide an efficient solution, one that is corrosion-resistant, to retrofit thousands of corroded CMPs across the country. High specific strength, high strength to weight ratio, corrosion resistance, …

Integrated Design Approach For Coronary Stents Using Flexinol Shape Memory Alloy, Matthew Lucci

Mechanical Engineering Theses

This research seeks to develop and verify a model for control of the shape memory alloy (SMA) Flexinol and apply such findings to practical application of the material as a platform for bare metal stenting technologies. Utilizing experimental data and material properties, a mathematical model of the thermoelectric contraction behavior of Flexinol wire samples was developed. This model accounted for variable resistance due to the shape memory effect of the Flexinol wire as it experiences a crystalline phase change. It also accounted for the change in the cross-sectional area of the wire as the wire experienced thermal expansion and contraction. …

Non-Trivial Off-Path Network Measurements Without Shared Side-Channel Resource Exhaustion, Geoffrey I. Alexander

Computer Science ETDs

Most traditional network measurement scans and attacks are carried out through the use of direct, on-path network packet transmission. This requires that a machine be on-path (i.e, involved in the packet transmission process) and as a result have direct access to the data packets being transmitted. This limits network scans and attacks to situations where access can be gained to an on-path machine. If, for example, a researcher wanted to measure the round trip time between two machines they did not have access to, traditional scans would be of little help as they require access to an on-path machine to …

Experimental Study Of Condensation In A Thermoacoustic Cooler With Various 3d Printed Regenerators Using Water Vapor As The Working Fluid, Aibek Bekkulov, Andrew Luthen, Ben Xu

Mechanical Engineering Faculty Publications

Thermoacoustics (TA) deals with the conversion of heat into sound and vice versa. The device that transfers energy from a low temperature reservoir to a high temperature one by utilizing acoustic work is called TA cooler (TAC). The main components of a typical TAC are a resonator, a porous regenerator (e.g. stack of parallel plates) and two heat exchangers. The thermoacoustic phenomenon takes place in the regenerator where a nonzero temperature gradient is imposed, and interacts with the sound wave. The low temperature at the cold end of TAC can be used to condense water from the humid air and …

3d Chocolate Printer Bed Design, Dean Oken, Jacob Margolin, Ben Hartmann, Sam Grossman

Mechanical Engineering Design Project Class

The client wished for a device to gain the interest of young undergraduate students into basic thermal science and fluid dynamics concepts. A 3D printer bed was created from concept to prototype design and paired with chocolate dropper teams to complete the project and accomplish the client's goals.

Mems 411 Group L (Fall 2019) - Speedy Seeder Final Report, Michael Morrow, Christopher Nelson, Ross Frame

Mechanical Engineering Design Project Class

The Speedy Seeder or ”SS” is a device designed to decrease the time it takes to fill one seed plot by hand to roughly sixteen percent of the time. The customer of the SS is EarthDance Organic Farms School. EarthDance fills a large number of plots each year by placing a seed in every single compartment which come in three sizes: 32, 72, and 128 compartments per plot. Filling a single plot by hand can take roughly 8 minutes. The SS makes filling a plot much easier and faster, allowing a single plot to be filled in under 75 seconds. …

Enhanced Heat Transfer Performance By Shape Optimization Of A Non-Axisymmetric Droplet Evaporating On A Heated Micropillar, Haotian Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Abstract

Enhanced Heat Transfer Performance by Shape Optimization of a Non-axisymmetric Droplet Evaporating on a Heated Micropillar

By

Haotian Wu

Department of Mechanical Engineering and Materials Science

Washington University in St. Louis, 2019

Research Advisor: Professor Damena Agonafer

The stacked multilayer 3D IC structure used in next generation high-powered electronics poses great challenges in dissipating their large heat flux, which causes extreme difficulties for traditional cooling technologies. In response, more advanced two-phase liquid cooling technologies, such as droplet evaporation, which utilizes the latent heat of vaporization to remove excessive heat, have been widely investigated. Compared to traditional single-phase cooling techniques, …

Design Of A Flexible System Simulation Evaluation Framework, Rusheng Ju, Zimin Cai, Wang Song, Wang Peng

Journal of System Simulation

Abstract: To meet variable evaluation requirement of complex system simulation, this paper puts forward a design strategy of flexible effectiveness evaluation framework. The composition structure of system simulation evaluation framework is analyzed. To help users design reference dynamically, the method of evaluation reference edit and display is introduced based on Web. To enhance the extensibility of evaluation model, the method of interface design and code generation is investigated. To ensure the flexibility and extensibility of evaluation framework, the relation and mapping mechanism of evaluation references, evaluation model and evaluation result is studied. The framework is realized and verified in …

Research On Simulation Platform For Equipment System Analysis, Yuping Li, Shaojie Mao, Zhenqi Ju, Zhou Fang, Guoqiang Yan

Journal of System Simulation

Abstract: With the development of equipment construction from platform-centric to network-centric, simulation analysis of equipment system is an important means and tool to support the transformation and development of equipment construction under the condition of multi-task joint operation. Starting from the requirement of system simulation analysis, a cloud-based equipment system simulation architecture is proposed to realize flexible and configurable simulation environment according to task requirements; and a high-performance simulation framework is conducted, which provides strong support for different application modes, such as parallel hyper-real-time and distributed simulation deduction. The unified description, organization and management method of model and data resources …

Design And Finite Element Analysis Of Reflector Spherical Shell For Flight Simulator, Hailiang Bai, Jiang Nan, Zhang Liao, Yuewen Fu

Journal of System Simulation

Abstract: The fight simulator with six-degree-of-freedom motion platform can simulate the flight attitude in real time and provide realistic overload dynamic feeling, which requires that the equipment on the platform must adapt to the overload during flight simulation. To solve the contradiction between the rigidity and weight of material, the glass fiber composite material is used to design and manufacture the spherical shell of the mirror . To improve the optical collimation of the reflector, the specific hyperboloid aspheric surface is selected as the surface design scheme,the 3D model of the spherical shell is constructed. The parameters of the …

Numerical Simulation Of Rock Breaking Mechanism For Compound Percussion Drilling, Yumei Li, Liwei Yu, Zhang Tao, Su Zhong, Jianming Liu

Journal of System Simulation

Abstract: The ABAQUS dynamic impact module is used to establish the numerical calculation model for PDC single tooth-rock impact. The effects of PDC cutting teeth on the dynamic rock breaking mode and rock breaking effect under the combined action of rotating speed, drilling pressure, alternating impact torque and alternating impact force are studied. The study shows that the torsional impact mode is 39.28% higher than the rock breaking efficiency of the rotary impact, and the compound percussion mode is 27.79% higher than the rock breaking efficiency of the torsional impact. Under the same conditions of impact time, the rock surface …

Research On Corridor Setting Based On Pedestrian Simulation Of Social Groups, Yiting Xu, Zhang Rui

Journal of System Simulation

Abstract: As the connector of each space in the hub, the rail transit hub corridor plays the role of transition and buffer. The existence of social groups makes an important impact on pedestrian traffic and its simulation. The paper supplements the consideration of pedestrian traffic related studies on social groups travel, analyses the characteristics of social groups in rail transit hub corridor, improves Moussaïd social group force model, and redevelops AnyLogic micro-simulation platform based on Python language. Taking a subway station in Beijing as an example, fully considering the influence of social groups, it is obtained that the optimal channel …

Research On Simulation Optimization Of Disk-Based Storage Operation Mode In Warehouse, Danlan Xie, Liu Meng, Haihong Yu, Chen Jing, Yubo Zhou, Kazi Mohiuddin

Journal of System Simulation

Abstract: As the efficiency of operation affects the overall competitiveness of the port, it is very necessary to design the storage operation mode reasonably. A disk-based storage operation mode is proposed. And the simulation model is established by using the logistics simulation software FlexSim based on the operational requirements of the warehouse. Through a large number of simulation experiments, comparing the primary storage mode with the disk-based storage mode, the results of the increase in total idle rate and the more balanced distribution of each hour utilization ratio of the forklifts are obtained. The result verifies the feasibility and effectiveness …

Research On Extraction Method Of Time-Frequency Feature Of Fall Detection, Tianrun Wang, Su Zhong, Liu Ning, Li Chao, Guodong Fu

Journal of System Simulation

Abstract: Aiming at the problem of features extract method for fall detection, the method using time-frequency analyze and features extraction by Fractional Fourier Transform (FRFT) has been proposed. The inertial data is measured by 15 IMU wearing on body, the features extracted after FRFT with multiple order are analyzed and compared. The difference of feature distribution of eight fall actions has been compared, and the difference of feature distribution between fall action and 4 normal actions has been compared. The feasibility of using FRFT in fall detection is proved.

Parallel Tasks Optimization Scheduling In Cloud Manufacturing System, Chenwei Feng, Wang Yan

Journal of System Simulation

Abstract: To solve the problem of unbalanced resource requirements and low resource utilization when the same type of tasks are executed in parallel in the cloud manufacturing system, a task resource scheduling model with the goal of minimizing cost, minimizing time, maximizing reliability and optimizing quality is established. A non-dominated sorting genetic algorithm based on reference points (NSGA-III) is adopted to solve the model by combining real number matrix coding and crossover and mutation based on real number coding instead of common evolutionary strategy. And an optimal decision strategy based on combination of analytic hierarchy process and entropy value method …

Comparative Study On Resistance Modeling Method In Yacht Simulator, Xiaochen Li, Yin Yong

Journal of System Simulation

Abstract: In order to solve the problem that the existing resistance modeling method of yacht has poor universality and the calculation accuracy is not high, approximate resistance modeling methods of high speed craft are analyzed and summarized. The actual yacht model is simplified into a prismatic hull. “ЦАГИ” method and SIT method are reproduced and the simulation results are compared with model test. The application of resistance approximate modeling in the yacht simulator is discussed. The results reveal that the resistance is in good agreement with the experimental value, and the SIT method with simplified hull form is more …

Research On The Value Accessing Method For Calibrating Micro Traffic Simulation Model Parameters, Chenjing Zhou, Rong Jian, Kwok Lam

Journal of System Simulation

Abstract: Parameter calibration is the precondition of the application of micro traffic simulation technology. This study focuses on the value accessing method for parameter calibration in order to further improve the parameter calibration process. The analysis of the distribution characteristics of each parameter calibration results shows that the parameters have different trends in the process of gradual iteration, and there are multiple optimal solutions for the model parameter calibration results. In this paper, the dispersion is used as the quantitative analysis index of the concentration degree of each parameter calibration result, and the parameter value of the model is determined …

Research On Source Seeking Methods Of Harmful Gas Leakage In Chemical Industry Parks, Zhao Yong, Bin Chen, Xiaodong Wang, Zhengqiu Zhu, Rongxiao Wang, Xiaogang Qiu

Journal of System Simulation

Abstract: Chemical production safety accidents often lead to harmful gas leakage, causing serious environmental damage and casualties. Mastering the information of leaking source quickly can assist in emergency disposal decisions and reduce the harm of accidents. In this paper, Entrotaxis algorithm is used to guide the ground source seeking equipment to move to the vicinity of the leaking source quickly and autonomously in a chemical park scene, and to master the source information. According to the characteristics of the chemical industry park scene, this paper applies intermittent search module into Entrotaxis algorithm and proposes a robust and suitable algorithm (Entrotaxis-Jump …

Numerical Simulation Analysis Of Anti-Blast Impact Of Underground Rescue Capsule Based On Ls-Dyna, Zhang Fan, Yuanhua Yang, Xiaoxu He, Deng Yu

Journal of System Simulation

Abstract: Aiming at the strength problem of the underground rescue cabin under explosion impact load, a finite element model of overall explosion impact load and fluid-solid coupling structure response is established in transient dynamic soft LS-DYNA. The flow field impact load is generated by explosion algorithm, and the propagation of the impact load in the air is calculated. The dynamic response of the rescue cabin structure under the impact load is calculated by the fluid-solid coupling method. The results show that the maximum load occurs on the end surface closest to the explosion source, and the structural deformation is small …

The Scheduling Algorithm Of Cloud Job Based On Hopfield Neural Network, Yudong Guo, Jinping Zuo

Journal of System Simulation

Abstract: Focusing on the low efficiency of cloud job scheduling and the insufficient utility of resource, a job scheduling algorithm based on Hopfield Neural Network is proposed. In order to improve the resource scheduling ability of the system, The resource characteristics which influence the cloud job scheduling are shown. The mathematical model of resource constraints is established, and the Hopfield energy function is designed and optimized. The average utilization rate of 9 nodes is analyzed by using the standard test cases, and the performance and resource utilization of the proposed strategy are compared with three typical algorithms. …

Simulation Research On Attitude Solution Method Of Micro-Mini Missile, Chunbo Zhao, Junfang Fan, Liu Ning

Journal of System Simulation

Abstract: Aiming at the problem of attitude measurement error in the inertial navigation system of micro and small guided ammunition under eccentric structure, the attitude solution and error compensation optimization are studied by using rotation vector optimization of multiple sub-samples, such as monotone sample, two sub-samples, three sub-samples and four sub-samples, and the fourth-order runge kutta algorithm. Through error compensation and optimization of measured data, the results show that the monomorphic modified algorithm has the worst optimization effect, the fourth-order runge kutta optimization algorithm has the best effect, and the maximum drift error of attitude Angle is better than 10 …

Multi-Objective Optimization Design Of Aerodynamic Layout For Twin Swept-Wing Aircraft, Yuchang Lei, Dengcheng Zhang, Yanhua Zhang, Guangxu Su, Luo Hao, Zhan Ren

Journal of System Simulation

Abstract: Multi-objective optimization of aerodynamic layout is a key technology in the design of vehicles. The overall configuration of the shape parameters is optimized with a double swept-shaped wave shape as the basic configuration. We use NSGA-Ⅱ multi-objective genetic algorithm, take the aircraft double sweep angle as the design variable, consider the maximum takeoff weight, range, volume ratio and other performance indicators, use Elman neural network to establish the relationship between shape parameters and performance parameters, and establish constraints based on mission planning requirements. The Pareto optimal solution set is obtained by using optimized design and the individuals with …

Fast Simulation Of Yacht In Calm Water Based On Improved Savitsky Method, Xiaochen Li, Yin Yong

Journal of System Simulation

Abstract: An improved Savitsky method is proposed to increase the accuracy of mathematical model of yacht in fast simulation. Three degrees of freedom mathematical model is established to simulate the motion in displacement regime. warped hull forms of yachts are simplified into prismatic hull and improved Savitsky method is used to calculate resistance. The simulation is carried out in pre-planing regime and planing regime. The validity of the proposed method has been assessed by comparing results with previous experimental data, which shows good agreements. The improved method runs well and the result is accurate when it is added to the …

Knowledge Representation Method Of Joint Operation Situation Based On Knowledge Graph, Baokui Wang, Wu Lin, Xiaofeng Hu, Xiaoyuan He

Journal of System Simulation

Abstract: Lacking of common knowledge for understanding and judging complex situation of operation by machines is one of the difficulties in intelligent situation cognition. The knowledge representation methods based on knowledge graph are reviewed. The characteristics and difficulties of joint operation situation knowledge representation are analyzed. Moreover, the concept of scenario knowledge graph is presented, as well as the knowledge sources and basic content of scenario knowledge graph are described. This paper also points out that the joint knowledge representation method based on discrete symbols and continuous vectors in specific scenario is an effective way to express joint operation situation …

Design Of Imu Dynamic Coefficient Calibration Based On Reduced Space Search Algorithm, Hongyan Yan, Zhang Yu, Weihua Zhu, Shi Ming, Yexin Zhang

Journal of System Simulation

Abstract: In order to improve the dynamic error coefficient speed of the calibration strapdown inertial group, a dynamic error model is established in the inertial navigation system. The Kalman filter is used to reflect the observation degree of the error term to determine the objective function of the optimal algorithm. The penalty function for the reduced space search algorithm is improved by genetic algorithm. At the end, it not only gets rid of the interference of the local pseudo-optimal solution, but also improves the recognition speed when it is close to the optimal solution. Compared with the solution …