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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.

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.

This paper was removed from publication at the author’s request. February 18, 2021. Copyright © 2021 by ASME

This paper was removed from publication at the author’s request. January 15, 2021. Copyright © 2021 by ASME

This paper was removed from publication at the author’s request. December 9, 2020. Copyright © 2020 by ASME

The above referenced paper has been removed from publication at the author’s request. October 2, 2020. Copyright © 2020 by ASME

The above referenced paper has been removed from publication at author’s request. September 9, 2020. Copyright © 2020 by ASME

The above referenced paper has been removed from publication. (April 21, 2020) Copyright © 2020 by ASME

The above referenced paper has been removed from publication. (April 21, 2020) Copyright © 2020 by ASME

The above referenced paper has been removed from publication. (March 11, 2020) Copyright © 2020 by ASME

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

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

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

This erratum corrects errors that appeared in the paper “A Hydrofoil Configuration for Wind Powered Energy Ship Applications” which was published in Proceedings of the ASME 2017 Fluids Engineering Division Summer Meeting, Volume 1B, Symposia: Fluid Measurement and Instrumentation; Fluid Dynamics of Wind Energy; Renewable and Sustainable Energy Conversion; Energy and Process Engineering; Microfluidics and Nanofluidics; Development and Applications in Computational Fluid Dynamics; DNS/LES and Hybrid RANS/LES Methods, V01BT07A003, July 2017, FEDSM2017-69402, doi: 10.1115/FEDSM2017-69402.

This erratum corrects errors that appeared in the paper “Analysis of the Performance of Plasma Actuators Under Low-Pressure Turbine Conditions Based on Experiments and URANS Simulations” which was published in Proceedings of ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, Volume 2A: Turbomachinery, V02AT40A034, June 2017, GT2017-64867, doi: 10.1115/GT2017-64867.

The Queensland Geothermal Energy Centre of Excellence (QGECE) has been developing a small 7 kW refrigerant radialinflow turbine assembly. Such turbines, when used with organic fluids (e.g. refrigerants), result in power cycles that can have a superior thermodynamic efficiency compared to traditional power cycles and turbines in the low to medium temperature range (100-250°C). The intended use for the UQ 7kW turbine unit is validation of CFD simulations, characterisation of turbomachinery loss mechanisms, and validation of 1-D design methodologies. This paper describes the structural and aerodynamic design process that has led to completion of the turbine unit. The first generation aerodynamic design (rotor and stator) and operating points were selected using the QGECE's 1-D mean line design software TOPGEN, to obtain a simple and robust turbine. Results from preliminary CFD simulations to verify the volute and stator operation and stage simulations to provide design and off-design performance characteristics and structural loads are presented. The turbine assembly was designed with modularity in mind to allow future turbine design iteration. Design information is provided for the overall turbine concept and the modular sub-components, including volute, magnetic coupling, bearing chamber design, shaft rotordynamics, FEA analysis and the instrumentation scheme. The paper concludes with a summary of the planned tests.

This paper was withdrawn. ASME does not hold the copyright. December 21, 2018. Copyright © 2018 by ASME

This paper was not presented at the conference. ASME does not hold the copyright. December 21, 2018. Copyright © 2018 by ASME

This erratum corrects errors that appeared in the paper “Forced Response Analysis of a Mistuned Compressor Blisk Comparing Three Different Reduced Order Model Approaches” which was published in Proceedings of ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, Volume 7A: Structures and Dynamics, V07AT32A030, June 2016, GT2016-57902, doi: 10.1115/GT2016-57902.

This erratum corrects errors that appeared in the paper “Fatigue Strength Assessment of Propellers by Means of Weakly Coupled CFD and FEM Analyses” which was published in Proceedings of the ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering, Volume 7: Ocean Space Utilization; Professor Emeritus J. Randolph Paulling Honoring Symposium on Ocean Technology, V007T12A029, June 2014, OMAE2014-24655, doi: 10.1115/OMAE2014-24655.

This erratum corrects errors that appeared in the paper “A Concise Methodology for the Design of Statically-Equivalent Deep-Offshore Mooring Systems” which was published in Proceedings of the ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering, Volume 1A: Offshore Technology, V01AT01A004, June 2014, OMAE2014-23054, doi: 10.1115/OMAE2014-23054.

To realize engineered materials and structures via origami methods and other folding construction techniques, fundamental understanding of paper folding mechanics and their dependency on paper micro/nanostructure is needed. Using selected papers commonly used in origami designs, we establish the relationship between the mechanical properties of fibrous paper and their corresponding ability to form and retain simple creases and mountain/valley folds. Using natural fiber paper (abaca), synthetic fiber paper (Tyvek), and a metal-fiber laminate paper, we studied how the fold radius depends on the load applied using a controlled rolling apparatus. After folding, we examined the resultant micro- and nanoscale deformation using electron microscopy. In general we found that the fold radius follows a power law, decreasing with the applied rolling force. At a critical strain, each paper exhibits a transition between elastic and plastic behavior, after which the trend asymptotically approaches the minimum fold radius with increased applied force. Finally, we present examples of centimeter-scale two-dimensionally “mountain fold” patterns and relate the folding characteristics observed in these designs to the mechanical properties of the papers in folding.Copyright © 2013 by ASME

Microbial fuel cells (MFCs) have been a potential green energy source for a long time but one of the problems is that either the technology must be used on a large scale or special equipment have been necessary to keep the fuel cells running such as syringe pumps. Paper-based microbial fuel cells do not need to have a syringe pump to run and can run entirely by themselves when placed in contact with the fluids that are necessary for it to run. Paper-based microbial fuel cells are also more compact than traditional MFCs since the device doesn’t need any external equipment to run. The goal of this paper is to develop a microbial fuel cell that does not require a syringe pump to function. This is done by layering chromatography paper with wax design printed onto it. This restricts the fluids to a specific flow path allowing it to act like the tubes in a typical microbial fuel cell device by delivering the fluids to the chamber. The fluids are picked up by tabs that sit in the fluid and use capillary attraction to flow up the tab and into the device. The fluids are directed to the chambers where the chemical and biological processes take place. These flows are then directed out of the device so that they are taken to a waste container and out of the system. Our microliter scale paper-based microbial fuel cell creates a significant current that is sustained for a period of time and can be repeated. A paper-based microbial fuel cell also has a fast response time. These results mean that it could be possible for a set of paper-based microbial fuel cells to create a power density capable of powering small, low power circuits when used in series or parallel. In this paper, we discuss the fabrication and experimental results of our paper-based microbial fuel cell. Also there will be a discussion of how paper-based microbial fuels cells compare to the traditional microbial fuel cells and how they could be used in the future.

The above referenced paper has been removed from publication. April 22, 2015. Copyright© 2015 by ASME

Reason: This paper was removed as a dual publication. Please see https://asmedigitalcollection.asme.org/ICEF/proceedings/ICEF2012/55096/83/238117. October 2, 2020. Copyright © 2020 by ASME

Gas turbine combustion chambers and turbine blades require better cooling techniques to cope with the increase in operating temperatures with each new engine model. Current gas turbine inlet temperatures are approaching 2000 K. Such extreme temperatures, combined with a highly dynamic environment, result in major stress on components, especially combustion chamber and blades of the first turbine stages. A technique that has been extensively investigated is transpiration cooling, for both combustion chambers and turbine blades. Transpiration-cooled components have proved an effective way to achieve high temperatures and erosion resistance for gas turbines operating in aggressive environments, though there is a shortage of durable and proven technical solutions. Effusion cooling (full-coverage discrete hole film cooling), on the other hand, is a relatively simpler and more reliable technique offering a continuous coverage of cooling air over the component's hot surfaces. This paper presents an innovative technology for the efficient effusion cooling of the combustor wall and turbine blades. The dedicated electroforming process used to manufacture effusive film cooling systems, called Poroform®, is illustrated. A numerical model is also presented, developed specifically for designing the distributions of the diameter and density of the holes on the cooled surface with a view to reducing the metal's working temperature and achieving isothermal conditions for large blade areas. Numerical simulations were used to design the effusive cooling system for a first-stage gas turbine blade. The diameter, density and spacing of the holes, and the adiabatic film efficiency are discussed extensively to highlight the cooling capacity of the effusive system.

This paper describes a methodology to set up models for simulation and diagnosis of energy plant components. The adopted approach consists in a simultaneous solution of modules representing plant components taking their actual behavior into account. Models are characterized by Reality Functions to adapt them to the reality of machines and apparatuses so that the New&Clean map of the real component can be established. Furthermore, to account for deterioration phenomena occurring during plant operations, Actuality Functions affecting component performance in terms of work and heat transfer, losses and effective flow functions have been introduced. Models have been validated and tested against real CHP plant data. Two applications to different kinds of power plants are presented and discussed. Results show a good capability to estimate component deterioration statuses and reproduce component actual behavior maps.

Second Law analysis or exergy analysis is a useful instrument to find ways to improve the efficiency of energy utilization. The method presents the magnitude and locations of true energy losses in an energy system. The pulp and paper industries have a big potential for increasing the energy efficiencies. An integration of a gas turbine with an existing steam turbine plant is one possible way to increase the energy efficiency and the power production. The cogeneration plant analysed in this paper is a hybrid combined plant in which two types of fuels are used. The exhaust gas from a combined cycle gas turbine via a waste heat recovery steam generator (HRSG) is used as preheated combustion air in a supplementary fired steam boiler. Saturated steam from the HRSG is assumed to be superheated in a boiler in which sludge, bark and other types of biomass are being used as fuels. To reduce the waste of energy, a flue gas driven fuel dryer is connected to evaporate some of the moisture in these biomass fuels. The study shows the effect of using a combined cycle instead of a simple steam cycle and the effect of using a fuel dryer. Among the configurations investigated, a plant with both a gas turbine and a fuel dryer yields the highest exergy efficiency and total efficiency. However, the net power efficiency is higher for a plant without a fuel dryer than for one with a fuel dryer.