Mechanical Engineering Commons^™

Investigation On Solar Assisted Liquid Desiccant Dehumidifier And Evaporative Cooling System For Fresh Air Treatment., Yi Chen, Hongxing Yang, Yimo Luo

Faculty of Science & Technology (THEi)

The widely used semi-centralized air conditioning (A/C) system consisting of independent fresh air system and fan coil system suffers from huge energy consumption, especially for fresh air treatment. Therefore, a liquid desiccant dehumidifier and regenerative indirect evaporative cooling (LDD-RIEC) system is proposed for fresh air treatment. The fresh air is handled by the LDD-RIEC system in which no electricity-intensive compressor involves. The hot and humid fresh air is firstly dehumidified by LDD and then sensibly cooled by RIEC. The thermal energy captured by solar collectors is used for desiccant solution regeneration. Indoor return air is cooled by fan coils of …

Further Development Of A Thermal Comfort Based Fuzzy Logic Controller For A Direct Expansion Air Conditioning System, Huaxia Yan, Yan Pan, Zhao Li, Shiming Deng

Faculty of Science & Technology (THEi)

The primary purpose of A/C is offering occupants with acceptable indoor thermal comfort levels. Thermal comfort is a complicated result of non-linear interactions between six parameters. However, many of current A/C systems solely control air temperature. Whenever anyone of the five parameters other than temperature varies significantly, an occupant may feel thermally uncomfortable. To address the issue, a comprehensive thermal comfort index should be used as regulator in A/C systems. One fuzzy logic controller is available. However, the approach to the fuzzy logic controller is complicated. In this paper, one previous established fuzzy logic controller is simplified for its real …

Experimental Study Of A Novel Subcooling Method Based On Liquid Desiccant Dehumidification For Vapor-Compression Refrigeration Systems., Xiaohui She, Yonggao Yin, Yimo Luo, Lindeman Brett, Dan Zhong, Xiaosong Zhang

Faculty of Science & Technology (THEi)

Refrigerant subcooling could increase the refrigerating capacity and potentially improve the performance of refrigeration systems. In this paper, a novel subcooling method is experimentally studied for the first time in a hybrid vapor compression refrigeration system. In this system, condensation heat (~40 °C) is used to drive an integrated subcooling cycle to subcool the refrigerant leaving the condenser, which significantly increases the system performance. Changes in system performance are measured as functions of the following variables: the mass flow rates of the dehumidification air, ambient air, dehumidification solution, regeneration solution, and spraying water. Comparisons are made between the proposed system …

Investigation On The Regeneration Performance Of Liquid Desiccant By Adding Surfactant Pvp-K30., Tao Wen, Lin Lu, Chuanshuai Dong, Yimo Luo

Faculty of Science & Technology (THEi)

The liquid desiccant cooling system (LDCS) is a promising alternative for the conventional vapor compression system due to its high energy efficiency. To enhance the mass transfer between the regeneration air and liquid desiccant in the regenerator, the paper firstly introduced a kind of surfactant called polyvinyl pyrrolidone (PVP-K30) which was added into the LiCl solution for better desiccant regeneration performance. The falling film characteristics and regeneration performance were investigated and compared with and without surfactant. The results indicated that the contact angle of desiccant solution on plate decreased from 58.5° to 28.0° by adding surfactant with 0.4% of concentration. …

Investigation On The Regeneration And Corrosion Characteristics Of An Anodized Aluminum Plate Regenerator., Tao Wen, Lin Lu, Hongxing Yang, Yimo Luo

Faculty of Science & Technology (THEi)

The traditional vapor compression cooling system (VCS) has been criticized for its heavy reliance on electricity consumption and limited control ability of humidity. Compared with the VCS, the liquid desiccant cooling system (LDCS) is more efficient by handling the sensible and latent load separately. The present study investigated the regeneration and corrosion characteristics of an anodized aluminum plate regenerator for the first time. Comparative tests were conducted to present the regeneration and corrosion characteristics of the normal and anodized regenerator. The influence of internal heating on the regeneration performance was also identified. The results showed that the corrosion rate was …

Inherent Operational Characteristics Aided Fuzzy Logic Controller For A Variable Speed Direct Expansion Air Conditioning System For Simultaneous Indoor Air Temperature And Humidity Control., Huaxia Yan, Yudong Xia, Xiangguo Xu, Shiming Deng

Faculty of Science & Technology (THEi)

Direct expansion air conditioning systems are widely installed in small-to medium- scale buildings due to their advantages of simple configuration, high energy efficiency and low cost to own and maintain. The two main targets of air conditioning operation include improving the system operational efficiency and energy efficiency. Stable system operational efficiency is directly related with the operation of electronic expansion valves and degree of superheat at the outlet of evaporator. In this paper, an adaptive DS controller is developed to improve the system operational efficiency based the experimental performance of a DX A/C system and reported. The adaptive DS controller …

Laser-Aided Additive Manufacturing Of Glass, John Michael Hostetler

Masters Theses

“This thesis presents various approaches for the laser-aided additive manufacturing of glass. First, a technique is investigated to create free-form, low to zero coefficient of thermal expansion structures out of silica-gel. A CO₂ laser was coupled through a gantry system and focused onto a binder-free silica-gel powder bed (15-40 μm particles). Prior to writing each layer, powder is dispensed by sifting it onto the build platform as opposed to a conventional wiper system, avoiding contacting and potentially damaging sensitive parts. After deposition, the parts are annealed in a furnace to increase their strength. The influence of various process parameters …

Investigation Of Combustion Characteristics Of A Heavy-Duty Diesel Engine Retrofitted To Natural Gas Spark Ignition Operation, Jinlong Liu

Graduate Theses, Dissertations, and Problem Reports

The conversion of existing diesel engines to natural-gas spark ignition operation by adding a gas injector in the intake manifold for fuel delivery and replacing the diesel fuel injector with a spark plug to initiate and control the combustion process can reduce U.S. dependence on petroleum imports and curtail engine-out emissions. As the conventional diesel combustion chamber (i.e., flat head and bowl-in-piston) creates high turbulence, the engine can operate leaner, which would increase its efficiency and reduce emissions. However, natural gas combustion in such retrofitted engines presents differences compared to that in conventional spark ignited engines. Subsequently, the main goal …

3d Global Acceleration Estimation Using Inertial Measurement Unit For Biomechanical Research, Revanth Raghuram Konda

Graduate Research Theses & Dissertations

The effects of mechanical vibrations on the body of a driver in off-road vehicles such as mining vehicles have become one of the intriguing research topics. To reduce the injuries of the operator of an off-road vehicle where vibrations of high magnitude occur, an indepth study of the nature of these vibrations must be done. The first step towards this objective is the correct estimation of acceleration of the vehicle by taking into consideration all the translational and rotational motion. The main goal of this study is the estimation of acceleration of an off-road vehicle in 3D space using an …

Design Optimization And High Cycle Fatigue Analysis And Of A Differential Case, Praveen Bulusu Surya Naga

Dissertations, Master's Theses and Master's Reports

Lightweight Innovations for Tomorrow (LIFT) is a consortium with several industries, universities and research institutes. It is operated by the American Lightweight Materials Manufacturing Innovation Institute (ALMMII). One of their projects, melt 5a, is to develop high silicon ductile iron (DI) alloys with improved mechanical properties and thin walled DI castings. These alloys have high strength to weight ratio compared to that of standard ductile iron (7003). Using these alloys, components can be re-designed that are much lighter which results in improved fuel efficiency, and reduced manufacturing costs and emissions. I

In this project, a differential case is being re-designed …

Optimization And Control Of An Array Of Wave Energy Converters, Jianyang Lyu

Dissertations, Master's Theses and Master's Reports

This study explored optimal configuration of both the array layout and the dimension of each WEC in the array. The array contains heaving buoys with full interaction and exact hydrodynamics. Optimization of dimension was done on each WEC in the array with a given optimal layout, and a higher q-factor was achieved. Both impedance matching optimal control and derivative control were employed, which provides both theoretical maximum energy and a more realistic case. Then the work was expanded to optimization of both the array layout and the dimension of each WEC in the array. An average of 39.21% higher q-factor …

Concerning The Construction Of Four-Bar Linkages And Their Topological Configuration-Spaces, Peter K. Servatius

Senior Projects Spring 2018

For a given linkage with one degree of freedom we can analyze the coupler curve created by any selected tracer point in relation to a driver link. The Watt Engine is a four-bar linkage constructed such that the tracer point draws an approximate straight line along a section of the coupler curve. We will explore the family of linkages that are created using Watt's parameters, along with linkages designed by other inventors; looking at methodologies of creating a linkage and the defining what we mean by approximate straight-line motion. Ultimately we will be creating our own linkage using what we …

Predicting Energy And Water Consumption On Dairy Farms Through Statistical Analysis And Machine-Learning Methods, Philip Shine

Theses

With the abolishment of milking quotas across all European Union member states in April 2015, dairy farmers must adjust their farming practises to minimise milk production costs to adequately prepare for potential periods of reduced revenue. Milk production is an intense energy and water consuming process. Coupled with challenging European greenhouse gas reduction targets and legislation regarding the prevention of groundwater pollution and deterioration, increasing the production of milk in Ireland must be met with the sustainable consumption of on-farm energy and direct water resources, to ensure the future monetary and environmental sustainability of Ireland’s dairy industry. Thus, this body …

Characterization Of Methane-Air Diffusion Flames For Flame Synthesis Application Through Optical Diagnostics, Zhaojin Diao

Theses and Dissertations--Mechanical Engineering

Flame synthesis is a growing field of research aiming at forming new materials and coatings through injection of seed materials into a flame. Accurate prediction of the thermal structure of these flames requires detailed information on the radiative properties and a thorough understanding of the governing combustion processes. The objective of this work is to establish a basic optical diagnostic characterization of different methane-air diffusion flames of different complexity. The basic principles are developed and demonstrated at a rotational symmetric co-flow burner and finally applied to a burner consisting of six clustered microflames which is designed for future flame synthesis …

Modeling And Analysis For Driveline Jerk Control, Prince Lakhani

Dissertations, Master's Theses and Master's Reports

In modern-day automotive industry, automotive manufacturers pay keen attention to driver’s safety and comfort by ensuring good vehicle drivability, feel of acceleration, limiting jerk and noise. The vehicle driveline plays a critical role to meet these criteria. By using high-fidelity simulation tool such as AMESim®, it is now possible to accurately model the vehicle driveline to be tested for different scenarios. With Simulink®, one can develop an efficient torque-based control system to limit the driveline oscillations and the generated noise. So, a joint simulation is used which provides a platform to evaluate the estimators and control system while considering the …

Direct Printing Of Single-Crystal Silicon By Microscale Nanoparticle Printing And Confined Laser Melting And Crystallization, Wan Shou

Doctoral Dissertations

"The transport and interfacial phenomena in laser melting and crystallization of silicon in micro-/nano-scale confinement lacks sufficient understanding. Uncovering the underlying mechanisms, and hence harness the melting and crystallization processes can help the formation of controllable single-crystal structures or patterns. In this dissertation, a molecular dynamics (MD) simulation was conducted to calculate the interfacial free energy of the silicon system in contact with flat and structured walls. Then the calculated interfacial energies were employed to predict the nucleation mechanisms in a slab of liquid silicon confined by two walls and compared with MD simulation results. Further, in combination with a …

Soy-Based Polyurethane Foam For Insulation And Structural Applications, Gurjot S. Dhaliwal

Doctoral Dissertations

"Polyurethane (PU) foams are widely used as insulation materials due to their high insulation properties and low cost compared to conventional materials such as styrene and mineral wool. PU foams are traditionally fabricated with petroleum-based precursors. However, high crude price and higher carbon footprint has lead interest of researchers to synthesis PU foams using plant-based raw materials, that are inexpensive and renewable. In this dissertation, PU foams were fabricated using soy-based polyol and its thermal and mechanical properties were investigated. In the first part, of PU foam samples with different formulations were fabricated using soy-based polyol HB230, and varying amounts …

Modeling And Control Of Probe-On-Probe Dynamics In Dual-Probe Atomic Force Microscopy, Ayad Al-Ogaidi

Doctoral Dissertations

“The atomic force microscope (AFM) is a widely used instrument for imaging and direct manipulation of materials and particles at the nanoscale. The AFM uses a probe, which is a microcantilever with a sharp point at the end. Typically, the AFM is constructed with a single probe. The disadvantage of this construction is that it can only be used either for imaging or manipulation in one implementation. An AFM was constructed using two probes, permitting simultaneous imaging and manipulation. A dual-probe AFM (DP-AFM) provides a foundation for feedback controlled manipulation.

Paper I investigates probe-on-probe contact stability and examines the dynamics …

Monitoring Of Hybrid Manufacturing Using Acoustic Emission Sensor, Haythem Gaja

Doctoral Dissertations

"The approach of hybrid manufacturing addressed in this research uses two manufacturing processes, one process builds a metal part using laser metal deposition, and the other process finishes the part using a milling machining. The ability to produce complete functioning parts in a short time with minimal cost and energy consumption has made hybrid manufacturing popular in many industries for parts repair and rapid prototyping. Monitoring of hybrid manufacturing processes has become popular because it increases the quality and accuracy of the parts produced and reduces both costs and production time. The goal of this work is to monitor the …

Modeling And Experimental Investigations On Particle Dynamic Behaviors In Laser 3d Printing With Blown Powder, Wei Li

Doctoral Dissertations

"Pre-mixed powder is frequently-used powder supply to fabricate Functional Gradient Material (FGM) by Laser 3D printing, which is also called Laser Metal Deposition (LMD). The deposited FGM composition is expected to be similar or same as supplied powder mixture. However, because pre-mixed powder has different particle densities and particle sizes, the caused particle acceleration differences can result in the separation in powder mixture. Up to now, there was no study focused on pre-mixed powders' flow behavior in LMD. The current research aims to investigate the flow behaviors of pre-mixed powder supplied for LMD through both experimental and modeling approaches. In …