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The Master of Science in Engineering program at Milwaukee School of Engineering has had its share of curriculum changes based on feedback from various stakeholders and annual assessment of the program leading to continuous improvement. One of the student outcomes is to have demonstrated an ability to integrate and analyze information in a chosen specialty in the form of scholarly work, either as an independent specialty paper or as an independent engineering project. And another outcome that follows is to have the ability to effectively present and communicate technical concepts, both orally and in writing. Even with all the engineering skills developed through discipline-specific coursework, these two outcomes were still quite a challenge to numerous students. While the program director takes measures to connect students with the appropriate advisor and even assists in technical content, the program needed and implemented the constant presence of a non-technical person as a member of the committee to improve communication of students through all stages of proposal writing, progress report and final report. We had tried one class of technical writing as a separate entity for students to take before they embarked on a capstone project, but the effectiveness varied as the principles had to be personally applied by the graduate student for the individual project. With the new approach, the student’s resources have grown, the project path has been made seamless, the effectiveness of working on the technical content and report writing in tandem right from the literature search and proposal development has resulted. The historic development of the current approach, including an overview of program educational objectives and student outcomes, is presented. The paper also showcases the results in terms of publications by the students who have grown in confidence in writing skills. This paper aims at enabling informed discussion for engineering graduate programs across the United States seeking to aid their students in this critical area of communication.

This paper was removed at the author’s request on December 1, 2022. Copyright © 2022 by ASME

The potential development of automated grading brings us the opportunity to change the way of teaching. In this paper, we present our pilot study of the correlations between the scores of engineering assignments and several task-independent features. This work aims to identify features that can subsequently be used in a machine learning framework to support automated grading. We also identified some interesting patterns in this dataset. Our result shows that length features such as word count may indicate a highly structured assignment’s quality, and the number of grammar errors has the potential to be part of the evaluation if we use a carefully designed grammar checker. The present study is expected to contribute to our understanding of automated grading of mechanical engineering technical reports and provide insights into rubric design for assignments.

This paper was removed at the author’s request on December 1, 2022. Copyright © 2022 by ASME

Paper production is an energy intensive industry but due to the wastes of its process (black liquor, waste biomass, sludge) has the capacity to generate most of its energy internally. Central to this balance are cogeneration units that guarantee the internal production of heat and electricity. These are sized for the company’s thermal load, with excess electricity injected into the grid. The efficient use of endogenous resources is a major route for improving the energy and environmental efficiency of the plant. Some of the waste materials include biomass wastes, sludges and other industrial wastes such as plastics. The present work aims to identify the opportunity of introducing a waste biomass gasification plant and the use of the produced synthesis gas, replacing the natural gas currently used in the turbine included in the company’s cogeneration unit. In this scenario, one of the cogeneration units in its current configuration has two steam boilers (one biomass; one black liquor) and a gas turbine whose waste heat feeds a recovery boiler to produce steam. The work involved several steps: the energy balance of the unit, the characterization of biomass residues (mixing bark, pine bark, eucalyptus bark, and refuse fibers), the test experimental analysis of residual biomass gasification and the characterization of the synthesis gas produced. In the electric and thermal energy producing units, gas turbines have a working efficiency above 35% while the steam turbines is considerably lower (15%). The efficiency of the chemical recovery boiler (79.5%) is lower than that of the biomass boiler (89.5%). From the experimental analysis of biomass it was found that most of them have a carbon and hydrogen content higher than 48 % and 5 %, respectively. In terms of higher calorific value (HHV), for the biomass where it was possible to determine it, the value is between 19.3 and 23.6 MJ/kg. These properties reveal that the selected biomasses from within the company, have potential as fuels. The limitation on its use may be due to the ash content, which tends to exceed 10 %. A gasification test (90 % eucalyptus biomass and 10 % mixture biomass) was also carried out to produce syngas and further characterization. The calorific value of the gas produced was 18 MJ/kg, with an absolute density of 1.17 kg/m3. It can thus be seen that for a gas turbine with a 35.8 % efficiency with a workload of 29.9 MWe 4.6 kg/s of syngas is required.

Small modular reactors (SMRs) are small-scale reactor designs (< 300 MWe), generally planned for deployment as multi-module nuclear power plants. Due to their small size, SMR modules could be manufactured in a factory and deployed to a site via truck or rail for installation and fueling. SMRs are being evaluated for their ability to provide both power and steam, such that they could be a viable replacement for fossil fuels. SMRs have been considered for coupling to manufacturing processes in addition to being connected to the grid, allowing them to follow the net grid demand in a “load following” operational mode during times of high renewable generation. Alternately, SMRs could be used to replace cogeneration and combined-cycle processes at manufacturing plants which utilize natural gas and other fossil fuels. Idaho National Laboratory (INL) is studying the use of SMRs for large-scale manufacturing processes that require both electricity and steam. The current study examines the integration of a SMR with two mid-size pulp and paper mills in the southeastern United States. The study consists of three parts: steady-state analysis of the mill, elimination of fossil fuel use in the lime kilns, and economic analysis of the modified plant operations. A steady-state model of each mill is developed in Aspen HYSIS based on real data from the operation of each mill. The steady-state model is then modified to include the SMR while maintaining production steam quality and making as few changes to existing equipment as possible. This model gives an estimate of the minimum requirements for SMR output, as well as the change in generation by existing boilers and turbines. With an overall picture of the new plant operation and determining the number of SMR modules required, further changes are suggested to minimize or completely eliminate fossil fuel use from the plant. Apart from steam generation, the largest consumer of fossil fuels at the plant is typically the lime kilns. Conversion of the lime kilns from fossil fuel combustion to electric heating is the most feasible solution to eliminate fossil fuels. This study finds that electric lime kilns are economical when the plant has a surplus This study presents a feasible example of using an SMR as a substitute for fossil fuel cogeneration. If this approach were expanded across the manufacturing industry, it would have a significant impact on environmental emissions and air quality.

The design and analysis of a paper-based microfluidic analytical device (μPAD) are presented in this paper for the detection of fentanyl and related synthetic opioids. Fentanyl, a synthetic opioid, is an extremely fast-acting synthetic narcotic analgesic having a high potency of approximately 100 to 200 times that of morphine. Detection of fentanyl can be done by colorimetric assays, i.e., spot tests with paper strips and μPADs which offer speed, simplicity of operation, portability, and affordability. The microfluidic behavior of liquid specimen and paper in the μPADs and test strips play a significant role in drug detection methods. Therefore, the study contains the fabrication of the test device using 3D printing and analysis of microfluidic behavior of the paper-based fentanyl test device. A multiphase computational fluid dynamics (CFD) model of a 3D microchannel is developed to evaluate the microfluidic properties. The CFD model incorporates the properties of cellulose and fentanyl solution to determine the flow parameters using the volume of fluid method. Wicking in the cellulose paper is studied analytically considering the Lucas-Washburn equation and Darcy’s law. Experiments with the fabricated μPAD and commercial test-kit samples are also conducted to compare the experimental results with the results for the flow parameters found from the numerical simulation.

Our niche method independently estimates hourly commuter rail station-to-station origin-destination (OD) matrix data each day from ticket sales and activation data from four sales channels (paper/mobile tickets, mail order, and onboard sales) by extending well-established transportation modelling methodologies. This algorithm’s features include: (1) handles multi-pack pay-per-ride fare instruments not requiring electronic validation, like ten-trip paper tickets “punched” onboard by railroad conductors; (2) correctly infers directionality for direction-agnostic ticket-types; (3) estimates unlimited ride ticket utilization patterns sufficiently precisely to inform vehicle assignment/scheduling; (4) provides integer outputs without allowing rounding to affect control totals nor introduce artifacts; (5) deals gracefully with cliff-edge changes in demand, like the COVID19 related lockdown; and (6) allocates hourly traffic to each train-start based on passenger choice. Our core idea is that the time of ticket usage is ultimately a function of the time of sale and ticket type, and mutual transformation is made via probability density functions (“patterns”) given sufficient distribution data. We generated pre-COVID daily OD matrices and will eventually extend this work to post-COVID inputs. Results were provided to operations planners using visual and tabular interfaces. These matrices represent data never previously available by any method; prior OD surveys required 100,000 respondents, and even then could neither provide daily nor hourly levels of detail, and could not monitor special event ridership nor specific seasonal travel such as summer Friday afternoons.

This paper was removed at the author’s request on October 22, 2021. Copyright © 2021 by ASME

This paper was erroneously published in ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition, Vol. 2D and removed on October 13, 2021. Copyright © 2021 by ASME

Microfluidic paper-based analytical devices (μPADs) are cost-effective point-of-care diagnostic devices. μPADs consist of porous filter paper patterned with hydrophobic solid ink barriers to create flow channels. Because a liquid sample flows through the paper channel driven by capillary force, the resultant flow is usually slow. To overcome this limitation, a hollow channel can be added to a μPAD to increase the flow speed significantly. The liquid flow through the hollow channel is known to be driven by a pressure difference between the inlet and outlet of the device. Accordingly, theoretical models have been proposed to understand and predict flow characteristics of μPADs with hollow channels. The goal of this study is to experimentally characterize liquid flow through μPADs having a hollow channel, by investigating relationships among the travel distance of the liquid front through the μPADs, the applied pressure difference, and the dimension of the hollow channel. Thus, the outcome of this study would contribute to validating the theoretical models and enable better control of liquid sample flow in μPADs with hollow channels.

Fatigue limit state design check for offshore wind turbines is based on SN curves and the Palmgren–Miner rule approach and focuses normally on stationary processes for which startup and/or shutdown operations induced transient load processes are normally not accounted for. However, large databases of real-time measurements show that the shutdown and startup operations may appear in any operational conditions and the frequency of such operations could be considerable. Although design standards require fatigue design checks for the transient load processes induced by startup and shutdown operations, relevant publications addressing this issue are very limited in particular for floating wind turbines. This paper focuses on analyzing the importance of startup and shutdown induced transient load processes on fatigue damage in the tower of two MW-level horizontal axis semi-submersible wind turbines. The analysis is carried on by comparing short-term fatigue damage in several environmental conditions with and without the startup and shutdown induced transient load processes. It is found that, in many environmental conditions, startup and/or shutdown operations may make an increase in short-term fatigue damage by 10% to 100%, while in some situations, the fatigue damage may be increased by up to 200%. The importance of the transient load processes on long-term fatigue damage is related to the occurrence frequency of startup and shutdown events. Publicly available data indicate that the average time between two consecutive shutdown events might be less than 39 h. However, more data and analysis are needed regarding these issues.

The paper industry uses cylinder dryers that employ steam to heat the paper web moving over the cylinder outer walls. As steam condenses, the condensate is accumulated inside the cylinder dryers. The condensate is evacuated using either stationary or rotary siphons. The form of condensate motion occurring inside the cylinder can be puddling, cascading or rimming depending on the size of the cylinder dryer, the rotating speed, the amount of condensate, and the surface finish of the cylinder dryer inner wall with or without ribs or grooves. The behavior of the condensate inside the cylinder dryers affects the heat transfer through the cylinder wall, the torque and power requirements of the dryer, and the performance of the condensate evacuation via siphons. To help improve the drying performance, it is important to understand the fundamental thermal-fluid physics in the rotational dryer. Thus, the objectives of this study are (a) to investigate the dynamic two-phase flow and heat transfer behavior inside the rotational paper dryer at different rotational speeds; (b) to employ three different multiphase computational models, the Volume of Fluid (VOF) model, the Mixture model, and the Eulerian-Eulerian (E-E) model, and compare their results. The results show that the E-E model better captures the physics of condensate behavior inside the dryer. It also predicts very well the rimming speed in comparison with the empirical correlation although it takes longer computational time than the VOF model. The mixture model doesn’t adequately capture the cascade and rimming physics due to excessive liquid dispersion. Based on the results, the categorization of the thermal-flow behavior of the liquid layer is expanded from the traditional three phases to five phases: puddling, transitional cascading, cascading, transitional rimming, and steady rimming. A detailed analysis of the rotating liquid layer behavior and its corresponding wall heat transfer passing through each phase is presented. Generally, the heat transfer increases during the initial puddling period, followed by oscillatory attenuation during the cascade period, finally reaches steady state after rimming is achieved.

This paper was removed from publication at the author’s request, February 26, 2021. Copyright © 2021 by ASME

This paper was removed from publication at the author’s request, March 8, 2021. Copyright © 2021 by ASME

The modern methodology for quantifying the quality of experimental data is uncertainty analysis. This paper is a review of current methods with some examples primarily from naval hydrodynamics. The methods described are applicable to fluids engineering. The paper discusses the history of uncertainty analysis, US and international standards on uncertainty analysis, verification and validation standards for computational fluid dynamics, and instrument calibration. One important result is that random loading in force calibration can produce a lower uncertainty estimate than sequential loading.

A general method is proposed to predict the shape of a paper model of a brassiere cup. A brassiere cup consists of several cloth and wire parts and the shapes of cloth parts are determined by repeating creation of a paper cup model, check of its 3D shape, and modification of 2D shapes of parts. For efficient design of a brassiere cup, prediction of its 3D shape with a simulation is required. The deformed shape of a paper part is represented as a single or multiple developable surfaces. So, a model that can represent a part both as a single surface and as multiple surfaces is proposed. Which case is selected depends on the magnitude of the potential energy of the part in each case. The potential energy of the part and geometric constraints imposed on the part are formulated based on the model. Minimizing the potential energy under geometric constraints derives the stable shape of the part in either case. Furthermore, our proposed method can be applied to prediction of the paper cup model consisting of parts with complex shapes.

Post-print (lokagerð höfundar), Wood and paper residues are usually processed as wastes, but they can also be used to produce electrical and thermal energy through processes of thermochemical conversion of gasification. This study proposes a new steady state simulation model for down draft waste biomass gasification developed using the commercial software Aspen Plus for optimization of the gasifier performance. The model was validated by comparison with experimental data obtained from six different operation conditions. This model is used for analysis of gasification performance of wood chips and mixed paper wastes. The operating parameters of temperature and moisture content (MC) have been varied over wide range and their effect on the high heating value (HHV) of syngas and cold gas efficiency (CGE) were investigated. The results show that increasing the temperature improves the gasifier performance and it increases the production of CO and H2 which leads to higher LHV and CGE. However, an increase in moisture content reduces gasifier performance and results in low CGE., This work was supported by the Icelandic Research Fund (IRF), grant number 196458-051.

The production printer market is expected to increase due to the demand in high speed printing. In electrophotographic (EP) process, the printing speed is restricted by the toner cooling time. During continuous printing, if the printing speed is too high, following paper is printed before the toner on previous paper is solidified, which results in the adhesion of the toner on previous paper to the next paper. Therefore, it is important to reduce the toner cooling time to improve the printing speed. From the viewpoint of printing quality, although toner temperature is important in EP process, paper temperature is not. Therefore, to improve the printing speed without worsening printing quality, this report focuses on suppressing paper temperature rise after fusing, which means a method to predict paper temperature after fusing is required. As one of effective approaches to predict paper temperature after fusing, numerical calculation based on physical model has been deployed. Constructing a physical model, however, has some problems such as complexity and uncertainty in particular parameter such as the thermal resistance. Printers have three dimensional and complex structure. The printing process itself is also a complex sequence to be appropriately modeled. It is also difficult to measure the thermal resistance and other properties due to the high speed motion of papers inside the machine. Therefore, as an alternative approach, machine learning can be used to correlate known inputs to the output temperature without relying on these uncertain parameters. The objective of this research is to propose a new method for predicting and controlling the paper media temperature after fusing in electrophotographic process by machine learning. Sensors are attached to the printer for the research. By using these sensors, temperature when printing is obtained. By using these data, machine learning is carried out to predict paper temperature after fusing. This report constructs a new method to predict paper temperature after fusing. Our study demonstrates machine learning is an effective method for predicting and controlling the paper temperature after fusing.

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This erratum corrects errors that appeared in the paper “Modeling the Gas Exchange Processes of a Modern Diesel Engine With an Integrated Physics-Based and Data-Driven Approach” which was published in Proceedings of the ASME 2019 Dynamic Systems and Control Conference, Volume 2: Modeling and Control of Engine and Aftertreatment Systems; Modeling and Control of IC Engines and Aftertreatment Systems; Modeling and Validation; Motion Planning and Tracking Control; Multi-Agent and Networked Systems; Renewable and Smart Energy Systems; Thermal Energy Systems; Uncertain Systems and Robustness; Unmanned Ground and Aerial Vehicles; Vehicle Dynamics and Stability; Vibrations: Modeling, Analysis, and Control, (V002T11A004), October 2019, DSCC2019-9226, doi: 10.1115/DSCC2019-9226.

Due to depleting natural resources, it is necessary to develop eco-composite materials that are fabricated from sustainable and inexpensive materials such as recycled paper or cellulose-based materials. Such materials are required to meet the mechanical performance at par with traditional materials. The main aim of this study was to investigate the mechanical performance of a composite material fabricated from paper pulp and polyvinyl acetate (wood glue). It is expected that a high strength composite material may be achieved by varying the amount of paper-pulp fiber fraction from 7.5%, 10%, 20%, 30%, 40%, 50% to 60% weight. A tensile test was conducted and it was found that an increase in fiber content on the fabricated composite resulted in an increase in ultimate tensile strength and a decrease in corresponding strain. Furthermore, the material becomes more brittle at higher fiber content and conversely, more ductile at lower fiber content. The ultimate tensile strength was found to be 7.69 MPa at 60% w.t fiber and the minimum tensile strength was 0.12 MPa at 0% w.t fiber. There were no signs of fiber content limit observed in the obtained results. It was concluded that a composite of moderate strength was produced and future work is required in order to fully understand how the composite behaves at different loading conditions. However, an optimum fiber content limit will have to be determined.

Large potential exists in recovering waste heat from paper industry processes and machinery. If the overall energy efficiency would be increased, it could lead to significant fuel savings and greenhouse gas emission reduction. The organic Rankine cycle (ORC) system is a very strong candidate for converting low-grade waste heat into power. However, there is a lot of water vapor containing latent heat in the exhaust gases from the drying process in the paper industry. Thus, the aim of this research work is to increase the efficiency of the ORC system by recovering not only the sensible heat but also the latent heat from the exhaust gases in the paper drying process. In order to recover the latent heat from the moist exhaust gases, one idea of this article is to introduce a direct contact condensing unit into the ORC system. The performance of ORC system with the direct contact condensing unit was analyzed by using the CHEMCAD software. A case study was conducted based on data of the exhaust gases from a tissue production / drying machine. Latent heat will be recovered when the evaporating temperature of the ORC working fluid is lower than the dew point of the water vapor in the exhaust gases. The results showed that the available heat load was increased when the evaporating temperature was reduced. Furthermore, a performance comparison of the ORC systems with and without the direct contact condensing unit was carried out in the case study as well. The results showed that the ORC system with the direct contact condensing unit not only could recover latent heat from the water vapor in the exhaust gases but also could have a small size and small volume evaporator in the ORC system.

This erratum corrects errors that appeared in the paper “Surface Bonding Graphene-Based Elastomeric Sensor: Preliminary Characterization of Adhesion Strength” which was published in Proceedings of the ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, (V001T01A002), September 2019, SMASIS2019-5578, doi: 10.1115/SMASIS2019-5578.

This erratum corrects errors that appeared in the paper “A Tomographic PIV Study and Comparison of Vortex Identification Methods on NACA 63-215 Hydrofoil Wake Structure” which was published in Proceedings of the ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference, Volume 4: Fluid Measurement and Instrumentation; Micro and Nano Fluid Dynamics, (V004T04A014), July–August 2019, AJKFluids2019-5550, doi: 10.1115/AJKFluids2019-5550.

The above referenced paper has been removed from publication. (March 10, 2020) Copyright © 2020 by ASME

Paper recycling is an effective way in reducing deforestation and energy consumption. Therefore recycling paper and paper products has been widely applied in many areas, such as packaging industry, film rolls, adhesive-tape industry, furniture decoration and temporary structures in building. They can be produced into various structure according to different requirement, such as paper tube, corrugated paperboard and normal paperboard. Paper-tubes gain more and more applications as a traditional structure due to their excellent mechanical property and environmentally friendly property. In order to meet various needs of paper-tube and produce high performance paper-tubes, designing for paper-tubes fabrication is needed. It is necessary to research the lateral compression strength of paper tube because various paper-tubes are used as packages, cores, poles and structure materials. To establish a relation of mechanical property between paperboards and paper-tubes is an important aspect. The current study is to investigate this relation. Paperboards are built from cellulose fibers jointed by hydrogen bonds and some additional elements like talc. The fibers are distributed randomly on the paperboards. However due to the tension action during fabrication process, more fibers are distributed in machine rolling direction which is defined as machine direction (MD, TD for transverse direction). The material expresses obvious anisotropic property. On the other hand, due to the laminated structure of paper materials, it is possible to generate interlaminar fracture in the usage process, especially in the construction made of paper such as paper tubes. The mechanical property of three kinds of paperboards used for paper-tubes fabrication was investigated included tension, compression and peeling combining with anisotropic property. These three kinds of paperboards have different mechanical properties but same dimension for paper-tubes fabrications. By this method, the effects of different properties including tension, compression and peeling on mechanical property of paper-tube could be evaluated. A series of paper-tubes with different layers was fabricated and the lateral compression test was carried out and evaluated. The fracture form of paper-tubes and fracture position on paper-tube were discussed together with paperboards. The cause of delamination behavior of laminated paper was analysis based on the detailed observation. The optical observation were employed to evaluate the fracture properties of paper-tubes after lateral compression test. It was found that the initial fracture of paper-tubes occurred inside the paperboards rather than between layers and the peeling property of paperboard has a signification effects on lateral compression property of paper-tubes.

This paper deals with the influence of surface contamination on the frictional mechanisms of rubber rollers. The contamination which adhered on the rollers after feeding many sheets of papers is one of the predominant causes of paper jams. However, the mechanism has not been understood. The purpose of this paper is to clarify the relationships between the friction force and the real contact area of papers and contaminated rubber rollers. Carrying out paper feeding tests by using a commercial multifunction peripheral, we tested different types of papers produced by different manufacturers. The tests have been done with combinations of different manufacturer’s papers and different kinds of roller materials. Observations of the real contact area clarified that the roller surfaces covered with paper powders or lint reduces the friction coefficient.

This work investigates the special case of in-plane fluid flow of a Newtonian incompressible fluid at low Reynolds numbers across a paper-thin porous medium in a confined conduit. Fluid transport in sheets with these characteristics are used in emerging devices such as microscale paper-based analytical devices (μPADs) and “e-paper” displays. Darcy’s law is applied and tested to determine if experimentally measured pressures at two flow rates of 5 μL/min and 10 μL/min agree with predicted values. A test device was designed using kinematic design principles to ensure a deterministic 318 μm gap that directs prescribed flow, unidirectionally across porous filter paper. The paper used was Grade 50 Whatman filter paper with an average pore size of 2.7 μm. Pressure was measured along the direction of flow over a 125 mm distance by six pressure ports placed at uniform increments of 25 mm to determine a profile of pressure along the flow path. Measurements were recorded at discrete time intervals over a period up to 48 hours with at least four replicates. Experimental measurements of the pressure profile show a linear relationship as predicted by Darcy’s law, allowing material permeability to be calculated. Among replicates measured under the same set of controllable conditions, experimental data also show a nonlinear relationship. The nonlinearity suggests evidence of transition into an inertia region, providing insight into the factors and behavior of the Darcy-Forchheimer transition for this special case of porous media flow.

In recent years, lower oil prices have forced many oil companies to reduce capex costs by revitalizing brown fields, rather than developing new green fields. At the same time, the offshore drilling rig market has seen many old rigs, typically used for shallow water operations, being scrapped, leaving new generation, deep and ultra-deep water MODUs as the only viable option for new drilling campaigns. Based on the above, wellhead fatigue on older assets, especially in harsh, shallow water environments, has started to gain a central role during the planning phases of workover and intervention operations. In recent years, Suncor Energy began investigating an extension to its Terra Nova field, which began production in 2002. The field uses subsea wells tied back to an FPSO which is moored in 95m of water off Canada’s eastern Grand Banks, an area frequented by icebergs. Drilling operations for the field extension were planned to commence in summer 2017, and continue with a year-round drilling campaign using a Cat 6 MODU. Since the extension would involve sidetracks and interventions from existing wellheads, a series of wellhead fatigue studies were undertaken using a variety of industry recognized methodologies [1] to understand the levels of fatigue accumulation. Although there has been no evidence of wellhead fatigue damage, Suncor chose to take a very prudent and proactive approach, aimed at minimizing fatigue, and maintaining fatigue life for potential future drilling operations. An Instrumented Wellhead Load Relief (iWLR) system was installed, which is designed to restrain BOP motions, thereby reducing the wellhead loads considerably. The load reduction system virtually eliminates additional fatigue accumulation for the planned operations. Additionally, the instrumentation system enables the precise monitoring and tracking of loads applied at the wellhead for future analysis. This paper describes the engineering challenges needed to develop and install the iWLR system in a harsh, shallow water, arctic environment. This area is characterized by very stiff soils pitted with iceberg scours, where subsea equipment must be protected within 10m deep excavated drill centers to prevent iceberg collisions in the relatively shallow water. Additionally, the paper describes how the instrumentation system was integrated with the BOP MUX cable communication system, for the first time, to enable real time monitoring of BOP motions using high accuracy gyroscopes and load cells which monitor dynamic iWLR tether forces. A topside data gathering and processing system was developed to present wellhead loads based on the indirect method, with new algorithms established to account for the tether forces. Finally, the paper presents some preliminary high-level results, showing the efficiency of the system based on measured data.

The objective of this paper is to develop in-situ structural health monitoring in polymer matrix composites using embedded bucky paper. Bucky paper based sandwich composites has been used for damage and load sensing in aerospace and defense applications due to high electrical conductivity, low density, and outstanding load sensitivity. Recent research focuses on improving mechanical, electrical, thermal properties of certain composites with improved gauge factor for sensing applications. To better understand certainly quantity strain change effects, it is essential to design composite materials and sensors for in-situ and embedded strain monitoring in composites using piezoresistance feedback. In this paper nanocomposite bucky papers are manufactured to monitor the load and damage condition in fiber reinforced polymer matrix composites. We first investigated the fabrication of bucky papers using different nanomaterials. Then the micro-scale morphology and structures are characterized using a scanning electron microscopy. The sensing function is achieved by correlating the piezoresistance variations to the stress or strain applied on the sensing area. Due to the conductive network formed and the tunneling resistance change in neighboring nanoparticles, the electrical resistance is able to show a good correlation with the load conditions. The prepared bucky papers are embedded in composites and the sensing capability is experimentally characterized under three-point bending experiments. The characterized membrane structures have the potential to be further applied to in-situ structural health monitoring and structural state awareness during their entire service lives.

This paper has been retracted by the American Society of Mechanical Engineers due the commercial nature of the content. December 21, 2018. Copyright © 2018 by ASME

Electrohydrodynamic processing including electrospinning and electrospraying is suitable for depositing controllable structures in fiber or film form. In this work, the electrohydrodynamic approach was used to prepare poly(vinylidene fluoride)/polyaniline composite film. Scanning electron microscopic analysis was performed to show the morphology of the film on soft tissue paper. Self-poling of the film was found due to the high voltage application in the electrohydrodynamic process. The addition of polyaniline into PVDF improves the conductivity of the film significantly. Mechanoelectrical response of the film was demonstrated by measuring the open circuit voltage of the specimens under bending. The peak voltage generated is over 1.2 V due to the bending deformation of the film. The film has ultrafast response to the deformation. It is concluded that the film has multiple functions for mechanoelectrical energy conversion, vibration sensing, and structural integrity monitoring applications.

Oil-free micro turbomachinery (OFT) implements compliant foil bearings because of their minute drag and ability to operate in extreme (high or low) temperature. Prominent to date, bump-type foil bearings integrate an underspring thin metal structure that provides resilience and material damping; and while the rotor is airborne, acts in series with the stiffness and damping of the gas film. The design and manufacturing of foil bearings remains costly as it demands of extensive engineering and actual experience. Alternative foil bearing configurations, less costly and easier to manufacture, are highly desirable to enable widespread usage of OFT. This manuscript details the design and manufacturing of a novel Rayleigh-step metal mesh foil thrust bearing (MMFTB) as well as its testing on a dedicated rig. Metal mesh structures offer significant material structural damping and can be easily procured at a fraction of the cost of a typical bump foil strip layer. The MMFTB consists of a solid carrier, a number of stacked annular Copper mesh sheets (wire diameter = 0.25, 0.3 and 0.41 mm), and a steel top foil (0.127 mm thick) that makes six pads (ID = 50.8 mm, OD = 2 ID), each 45° in extent. A 3 μm polymer coats each pad and a photo-chemical process etches a step 20 μm in height. Static and dynamic load measurements (without rotor speed) demonstrate the MMFTB has structural stiffness and material damping similar to that of a publicized bump-type foil thrust bearing. A maiden test of the MMFTB with rotor speed of Ω = 15 krpm (∼80 m/s at bearing outer diameter) proved briefly the bearing operation when applying a tiny thrust load. Further tests with ambient air, a rotor speed of 40 krpm (∼212 m/s at bearing OD), and a very light load/area < 7 kPa failed several of the prototype bearings, all exhibiting significant wear on one or more pads. The source of the failure is the inherent unevenness of the metal mesh stacked substructures, thus causing the pads to bulge towards the rotor collar surface before a load applies. A deficient anchoring method exacerbates the unevenness. Incidentally, a high rotor speed induced large windage that lifted the top foils pushing them against the spinning collar. As the bearing moved towards the rotating collar to begin applying thrust, the local high spots rubbed against the collar, before a hydrodynamic wedge could form to separate the surfaces. Without a robust sacrificial coating, metal-to-metal contact quickly disfigured the contacting top foil pads, erasing the etched step, and leading to failure. In concept, and on paper, the mesh sheets and the top foil lay flat against the bearing carrier, giving a false sense of uniformity in the design process. In actuality, a designer must consider the manufactured states of the individual components and how they assemble. A redesign of the bearing intends to overcome the existing flaws (highlighted herein) by incorporating a thicker top foil that is well anchored (to better withstand the effects of windage), a robust sacrificial coating, and a hydrodynamic wedge accomplished via a circumferential taper on each pad.

The above referenced paper has been removed from publication. (March 10, 2020) Copyright © 2020 by ASME

The above referenced paper has been removed from publication. (March 10, 2020) Copyright © 2020 by ASME