scholarly journals Effects of Turbine Design on Particulate Erosion of Turbine Airfoils

1991 ◽  
Author(s):  
J. H. Wagner ◽  
B. V. Johnson ◽  
D. W. Geiling
Keyword(s):  
Gas Turbines ◽  
Combustion Process ◽  
Particle Diameter ◽  
Surface Erosion ◽  
Erosion Rates ◽  
Trajectory Calculations ◽  
Design Characteristics ◽  
Turbine Airfoils ◽  
Turbine Design ◽  
Selection Of

An analytic study was conducted to determine the effects of turbine design, airfoil shape and material on particulate erosion of turbine airfoils in coal-fueled, direct-fired gas turbines used for electric power generation. First-stage, mean-line airfoil sections were designed for 80 MW output turbines with 3 and 4 stages. Two-dimensional particle trajectory calculations and erosion rate analyses were performed for a range of particle diameters and densities and for ductile and ceramic airfoil materials. Results indicate that the surface erosion rates can vary by a factor of 5 and that erosion on rotating blades is not well correlated with particle diameter. The results quantify the cause/effect turbine design relationships expected and assist in the selection of turbine design characteristics for use downstream of a coal-fueled combustion process.

Evolution of Gas Turbines Auxiliary Systems Designed for Reliability

1993 ◽  
Author(s):  
Jacek Misiowiec ◽  
Tim McElwee ◽  
Sal DellaVilla
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Operational Reliability ◽  
Design Approach ◽  
Design For Reliability ◽  
Design Evolution ◽  
Low Nox Combustion ◽  
Design Characteristics ◽  
Turbine Design

Gas turbine design evolution and practice is driven by industry demand for increased output and improved operating efficiencies. New aerothermal design characteristics require a focus on improved materials and coatings, and cooling techniques. As environmental issues continue to confront the industry, Dry Low NOx combustion system designs represent a significant opportunity for meeting new emissions requirements. These issues represent opportunity for significant technology improvements and industry driven advances. However, just as important is the design evolution of the Control and Auxiliary systems which support the gas turbine. Historically, these support systems, as demonstrated by the Operational Reliability Analysis Program (ORAP), are typically the primary drivers of plant Availability and Reliability. Following a rigorous “Design for Reliability” approach provides opportunities for ensuring that the design meets three critical requirements: starting reliability, a minimum of unit shutdowns during operating demand periods and ease of maintenance. The design approach for the Control and Auxiliary systems for new turbine design (product improvement) therefore provides an opportunity for developing a uniform and standardized approach which continues to focus on Reliability, Availability, and Maintainability. This design approach also provides opportunities for improved field installation and reduced cycle time, a major benefit for the end user. This paper will describe the “Design for Reliability” approach followed by ABB Power Generation, Inc., and supported by Strategic Power Systems, Inc.® (SPS) for the GT11N2 auxiliary systems. The extension of the ORAP system for auxiliary systems will be discussed as the approach for monitoring unit Availability and Reliability, maintaining configuration control, and for promoting continuous improvement.

scholarly journals The Gas Turbine-Air-Cleaner Dilemma

1963 ◽  
Author(s):  
Mark G. Mund ◽  
Thomas E. Murphy
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Field Tests ◽  
Air Cleaner ◽  
Air Cleaners ◽  
Long Life ◽  
Turbine Design ◽  
Dust Ingestion ◽  
Selection Of

The person confronted with the selection of a gas-turbine air cleaner is faced with a dilemma because the data available to guide his selection are inconsistent and not complete. The need for air cleaners has been established. The level of air-cleaner efficiency required to protect the gas turbine from the effects of dust ingestion has not. This paper reviews the data available and relates it to Donaldson Company experience. Air-cleaner specifications and how they are influenced by gas-turbine needs and experience are discussed. Today’s gas-turbine air cleaners and what they will do are reviewed. The paper concludes that it is essential to determine the level of air-cleaner protection required by the various gas turbines and suggests programs to determine it through laboratory and field tests. Further work in air-cleaner and gas-turbine design is suggested to obtain an optimum gas-turbine air cleaner and to obtain long-life gas turbines.

Experiences From the Joint Development of the GTX100 Turbine Blading

1998 ◽  
Author(s):  
Bengt Gudmundsson ◽  
Ulf Nilsson ◽  
Ulf Linder ◽  
Sergey Shukin ◽  
Igor Afanasiev ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Early Stage ◽  
Joint Project ◽  
Component Testing ◽  
Design Requirements ◽  
Engine Testing ◽  
Turbine Design ◽  
Industrial Gas Turbine ◽  
Selection Of ◽  
Turbine Blading

The GTX100 is the most recent industrial gas turbine in the ABB fleet. The development of the GTX100 turbine blading was a joint project involving four companies. A thorough evaluation of various design requirements resulted in the selection of a single shaft three-stage turbine configuration. The cooling techniques employed for the blading are based on the knowledge from the Russian school of design for gas turbines. These techniques have been verified by a considerable amount of experimental data and field experience over a number of years. To incorporate western manufacturing methods, western suppliers were introduced at an early stage in the development. Most of the engineering development of the turbine blading was carried out in Russia. In order to achieve efficient cooperation between Russia and Sweden, specialists from both companies were stationed at alternating companies. The verification of the turbine design is divided into two steps. The first step is cold and hot component testing and the second is the overall engine testing.

scholarly journals Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Low Noise ◽  
Closed Cycle ◽  
Propulsion Systems ◽  
Component Design ◽  
Readiness Level ◽  
Aerial Vehicle ◽  
Turbine Design

When selecting a design for an unmanned aerial vehicle, the choice of the propulsion system is vital in terms of mission requirements, sustainability, usability, noise, controllability, reliability and technology readiness level (TRL). This study analyses the various propulsion systems used in unmanned aerial vehicles (UAVs), paying particular focus on the closed-cycle propulsion systems. The study also investigates the feasibility of using helium closed-cycle gas turbines for UAV propulsion, highlighting the merits and demerits of helium closed-cycle gas turbines. Some of the advantages mentioned include high payload, low noise and high altitude mission ability; while the major drawbacks include a heat sink, nuclear hazard radiation and the shield weight. A preliminary assessment of the cycle showed that a pressure ratio of 4, turbine entry temperature (TET) of 800 °C and mass flow of 50 kg/s could be used to achieve a lightweight helium closed-cycle gas turbine design for UAV mission considering component design constraints.

scholarly journals Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3521 ◽  
Author(s):  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Ideal Gas ◽  
Point Of View ◽  
Pressure Gain Combustion ◽  
Combustion Technology ◽  
Secondary Air ◽  
And Performance ◽  
The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

Surface erosion assessment in the South-Canterbury downlands, New Zealand using 137Cs distribution

Soil Research ◽  
1995 ◽  
Vol 33 (5) ◽  
pp. 787 ◽  
Author(s):  
LR Basher ◽  
KM Matthews ◽  
L Zhi
Keyword(s):  
New Zealand ◽  
Mean Value ◽  
Slope Position ◽  
Surface Erosion ◽  
The South ◽  
Erosion And Deposition ◽  
Erosion Rates ◽  
Land Use Types ◽  
Radionuclide Tracer

Redistribution of the radionuclide tracer 137Cs was used to examine the pattern of erosion and deposition at two sites with contrasting long-term land uses (pasture and cropping) in the South Canterbury downlands, New Zealand. There were clear differences between the two land use types in variation in 137Cs concentrations and areal activity, erosion rates and topsoil depth variability. Erosion and deposition have resulted in greater variability and lower mean levels of 137Cs areal activity under cropping (46.3 mBq cm-2) than pasture (55.0 mBq cm-2). At the cropping site, erosion and deposition roughly balanced with the mean value over all sampling sites, suggesting no net soil loss, but considerable redistribution of soil within paddocks. At the pasture site results suggested slight net deposition. There was evidence for both sheet/rill and wind erosion being important in soil redistribution. While there was no difference in mean topsoil depth between pasture and cropping, there were significant differences with slope position. At the pasture site, there was little variation of topsoil depth with slope position, except for swales which tended to be deeper, whereas at the cropping site there was considerable variation in topsoil depth with slope position. Topsoil depth was a poor indicator of erosion status.

Comparison of Numerical Combustion Models for Hydrogen and Hydrogen-Rich Syngas Applied for Dry-Low-NOx-Micromix-Combustion

2016 ◽  
Author(s):  
H. H.-W. Funke ◽  
N. Beckmann ◽  
J. Keinz ◽  
S. Abanteriba
Keyword(s):  
Reaction Mechanism ◽  
Gas Turbines ◽  
Combustion Process ◽  
Computational Effort ◽  
Hydrogen Combustion ◽  
Combustion Stability ◽  
Research Approach ◽  
Pure Hydrogen ◽  
Nox Emissions ◽  
Combustion Models

The Dry-Low-NOx (DLN) Micromix combustion technology has been developed as low emission combustion principle for industrial gas turbines fueled with hydrogen or syngas. The combustion process is based on the phenomenon of jet-in-crossflow-mixing. Fuel is injected perpendicular into the air-cross-flow and burned in a multitude of miniaturized, diffusion-like flames. The miniaturization of the flames leads to a significant reduction of NOx emissions due to the very short residence time of reactants in the flame. In the Micromix research approach, CFD analyses are validated towards experimental results. The combination of numerical and experimental methods allows an efficient design and optimization of DLN Micromix combustors concerning combustion stability and low NOx emissions. The paper presents a comparison of several numerical combustion models for hydrogen and hydrogen-rich syngas. They differ in the complexity of the underlying reaction mechanism and the associated computational effort. For pure hydrogen combustion a one-step global reaction is applied using a hybrid Eddy-Break-up model that incorporates finite rate kinetics. The model is evaluated and compared to a detailed hydrogen combustion mechanism derived by Li et al. including 9 species and 19 reversible elementary reactions. Based on this mechanism, reduction of the computational effort is achieved by applying the Flamelet Generated Manifolds (FGM) method while the accuracy of the detailed reaction scheme is maintained. For hydrogen-rich syngas combustion (H2-CO) numerical analyses based on a skeletal H2/CO reaction mechanism derived by Hawkes et al. and a detailed reaction mechanism provided by Ranzi et al. are performed. The comparison between combustion models and the validation of numerical results is based on exhaust gas compositions available from experimental investigation on DLN Micromix combustors. The conducted evaluation confirms that the applied detailed combustion mechanisms are able to predict the general physics of the DLN-Micromix combustion process accurately. The Flamelet Generated Manifolds method proved to be generally suitable to reduce the computational effort while maintaining the accuracy of detailed chemistry. Especially for reaction mechanisms with a high number of species accuracy and computational effort can be balanced using the FGM model.

scholarly journals Effect on hand kinematics when using assistive devices during activities of daily living

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7806
Author(s):  
Alba Roda-Sales ◽  
Margarita Vergara ◽  
Joaquín L. Sancho-Bru ◽  
Verónica Gracia-Ibáñez ◽  
Néstor J. Jarque-Bou
Keyword(s):  
Activities Of Daily Living ◽  
Daily Living ◽  
Peak Velocity ◽  
Assistive Devices ◽  
Joint Angles ◽  
Kinematic Parameters ◽  
Hand Kinematics ◽  
Instrumented Glove ◽  
Design Characteristics ◽  
Selection Of

Assistive devices (ADs) are products intended to overcome the difficulties produced by the reduction in mobility and grip strength entailed by ageing and different pathologies. Nevertheless, there is little information about the effect that the use of these devices produces on hand kinematics. Thus, the aim of this work is to quantify this effect through the comparison of kinematic parameters (mean posture, ROM, median velocity and peak velocity) while performing activities of daily living (ADL) using normal products and ADs. Twelve healthy right-handed subjects performed 11 ADL with normal products and with 17 ADs wearing an instrumented glove on their right hand, 16 joint angles being recorded. ADs significantly affected hand kinematics, although the joints affected differed according to the AD. Furthermore, some pattern effects were identified depending on the characteristics of the handle of the ADs, namely, handle thickening, addition of a handle to products that initially did not have one, extension of existing handles or addition of handles to apply higher torques. An overview of the effects of these design characteristics on hand kinematics is presented as a basis for the selection of the most suitable AD depending on the patient’s impairments.

scholarly journals Review and decision support of options for the removal, treatment and disposal of stormwater sediments

2021 ◽  
Author(s):  
Panagiotis Koumoulas
Keyword(s):  
Decision Support ◽  
Stormwater Management ◽  
Erosion Rates ◽  
Beneficial Reuse ◽  
Runoff Decrease ◽  
Receiving Waters ◽  
Reuse Options ◽  
Treatment And Disposal ◽  
Operational Capacity ◽  
Selection Of

Stormwater management (SWM) ponds are a widely used option to control runoff, decrease flooding potential, reduce erosion rates in receiving waters and improve water quality. Although dredging and disposal are accepted practices, there is a need to consider alternative removal techniques, since 1) overall costs for a single pond can be substantial, and 2) a large number of ponds are approaching their operational capacity. It is evident that numerous remedial and beneficial reuse options are more economically viable and environmentally stable than current options. The intent of the current research was to develop guidance for municipalities and operators when faced with contaminated stormwater sediments. This paper presents a review of potential removal, treatment, disposal and beneficial use options and offers a simple decision support methodology to aid in the selection of options.

Theoretical and computational investigation of the electrochemical machining process for characteristic cases of a stepped moving tool eroding a plane surface

1997 ◽  
Vol 211 (3) ◽  
pp. 197-210 ◽  
Author(s):  
H Hardisty ◽  
A R Mileham ◽  
H Shirvani
Keyword(s):  
Plane Surface ◽  
Electrochemical Machining ◽  
Machining Process ◽  
Surface Erosion ◽  
Computational Investigation ◽  
Step Size ◽  
One Dimensional ◽  
Erosion Rates ◽  
Spatial Differences ◽  
The One

A theoretical and computational investigation into the electrochemical machining (ECM) process for the case of a moving stepped tool eroding an initially flat surface is presented. Five parametric variations of the basic geometry of the stepped tool machining process are possible, depending on the relative distance between the moving tool and eroded work. For each of the five cases, and based on one-dimensional theory, formulae have been developed to predict the minimum depth of working material that must initially be provided to enable a particular step size to be machined to a specified tolerance. The computer simulation of the ECM process which has been developed is based on the finite element method (FEM). The geometry of tool, electrolyte and work is simulated by means of a two-dimensional mesh of square elements. A system of macros has been developed which interact internally with an FE package to move component boundaries systematically to simulate both tool movement and surface erosion. Such boundary movements are accomplished automatically and continuously without user intervention during a simulation run. The algorithms employed to achieve characteristically different erosion rates are described. Results both from one-dimensional ECM theory and from the computer simulations of the characteristic cases are presented. Comparisons show that there is good agreement between computer predictions and theory. The differential erosion process is fundamental to all ECM processes. Complex shapes evolve because of spatial differences in erosion rates. Thus the one-dimensional results presented here for the formation of a step should provide a basis for comparisons between spatially separated regions of one-dimensional differential erosion on bodies of arbitrary shape.

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