bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developments Leading to an Axial Flow Compressor for a 25 MW Class High Efficiency Gas Turbine
Authors: Kashiwabara Y. , Katoh Y. , Ishii H. , Hattori T. , Matsuura Y. , Sasada T. 
Published: March 2015

In this paper, the development leading to a 17-stage axial flow compressor (pressure ratio 14.7) for the 25 MW class heavy duty gas turbine H-25 is described. In the course of developing the H-25’s compressor, extensive measurements were carried out on models. Experimental results are compared with predicted values. Aerodynamic experiments covered the measurements of unsteady flows such as rotating stall and surge as well as the steady-state performance of the compressor.
Based on the results of these tests, the aerodynamic and mechanical design parameters of the full scale H-25 compressor were finalized on the basis of two model compressors.
Detailed measurements of the first unit of the H-25 gas turbine were carried out. Test results on the compressor are presented and show the achievement of the expected design targets.
Potential Applications of Structural Ceramic Composites in Gas Turbines
Authors: Parks W. P. , Ramey R. R. , Rawlins D. C. , Price J. R. , Van Roode M. 
Published: March 2015

A Babcock and Wilcox - Solar Turbines Team has completed a program to assess the potential for structural ceramic composites in turbines for direct coal-fired or coal gasification environments. A review is made of the existing processes in direct coal firing, pressurized fluid bed combustors, and coal gasification combined cycle systems. Material requirements in these areas were also discussed.
The program examined the state-of-the-art in ceramic composite materials. Utilization of ceramic composites in the turbine rotor blades and nozzle vanes would provide the most benefit. A research program designed to introduce ceramic composite components to these turbines was recommended.
Design Considerations in the Development of a 38 MW Gas Turbine Cogeneration Facility
Authors: Hall Andrew D. , Hauhe William E. 
Published: March 2015

Cogeneration has proven to be an ideal application for gas turbines, one which subsidiaries of Texaco Producing Inc. and Mission Energy Company have developed in three successful projects to date. The 38 MW Mid-Set project is the latest, having been commissioned for commercial operation in April, 1989.
Several of the Mid-Set design features were developed from past operating experience, while other design features were employed to meet requirements specific to the project. Strict pollution control required the use of water injection, selective catalytic reduction, continuous emissions monitoring and minimal production of waste water. Other design considerations were plant availability, operability and efficiency for the continuous, base load operation of a turbine-generator. The design features and initial operating history of the Mid-Set cogeneration plant are described in this paper.
Free Convection Phenomena in a Ribbed Wall
Authors: Maravegias N. S. , Georgiou D. P. , Papailiou D. D. 
Published: March 2015

The present study reports on experimental information regarding the turbulent free convection flow and thermal field structure, along an isothermally heated vertical flat plate with ribs. The hight to distance ratio of the ribs was equal to 0.1.
The obtained experimental data consist of visualization of the flow, as well as detailed mean temperature and turbulent intensity distribution measurements covering the ribbed part of the heated plate. Heat transfer rates and their enhancement, due to the presence of the ribs, have been estimated from the obtained temperature profiles and by using Newton’s cooling law. Comparisons with corresponding measurements in forced convection reported in the literature, are also made.
The described experiments constitute a first approach towards a more detailed investigation regarding the significant free convection currents existing under certain conditions in cooled channels. However, they also reveal some physical aspects of the heat transfer enhancement processes in ribbed surfaces which are believed to be applicable in more general situations and could lead to establishing some design criteria for ribbed surfaces.
Offshore Experience of the LM2500 Gas Turbine
Authors: Spector R. B. , Cimino L. S. 
Published: March 2015

Approximately 50 years of offshore oil exploration drilling and production have led to refined techniques and equipment selection criteria. Gas turbines have established themselves as the prime source of energy transfer in that sector of the industrial marketplace where space and weight are of major importance. The increased worldwide demand for petroleum has pushed offshore platforms into deeper waters requiring further sophistication in the allocation of space, weight and maintenance resources. The aeroderivative gas turbine meets the above criteria and in addition offers the platform designer high thermal efficiency and system flexibility coupled with ease of maintenance.
This paper presents a summary of experience gained in over 10 years of operation of the General Electric LM2500 gas turbine on platforms in the North Sea. Although all of the circumstances that may be encountered cannot be adequately covered, highlighting the events which occurred in over one million hours of operation presents the potential user with a better understanding of the uniqueness of this type application. The advantages and the reliability of the aeroderivative gas turbine are also discussed.
The LM2500 gas turbine was first introduced into off-shore operation in the Norwegian sector of the North Sea in November 1979, after successful application in gas compression and transmission duty on pipelines and other on shore facilities.
User Experience in Upgrading Early Models of Aero Derived Gas Turbine Pipeline Compressor Units to Current Standards
Authors: Williams Lawrence J. , Pethrick David J. 
Published: March 2015

On July 3, 1964 TransCanada PipeLines Limited commissioned the first Rolls-Royce Industrial Avon, in a Cooper Bessemer pipeline compressor set. In 1986, Cooper-Rolls introduced upgraded versions of the Avon (1535E) and power turbine (RT48S). In 1987, TransCanada converted an Avon to 1535E standard at one location and power turbines to RT48S at two other locations. Following one year of acceptable operation, four units were converted to the “Production” standard with both Avon and power turbine upgraded in 1988.
Testing showed the old, modified units to achieve the performance guaranteed for new engines. The condition of the lead Avon 1535E at tear-down after 6000 hours is described, together with a statement on condition after 15000 hours. The four units modified in 1988 were torn down for inspection during the Summer of 1989, and their condition is discussed. Minor operating difficulties are described together with their solutions.
This paper publishes work that was presented without publication at the Toronto conference in June 1989 together with new information which has become available since that time.
Reconstruction of Individual Aerodynamic Performance Stage Characteristics From Multistage Compressor Flange-to-Flange Test Data
Authors: Sapiro Leon 
Published: March 2015

An iterative procedure was devised for reconstructing the aerodynamic performance characteristics of each of the stages of a multistage compressor when only the overall performance, determined from flange-to-flange measurements, is available.
The need for this procedure originated during the closed loop testing of a new family of centrifugal compressor stages. To reduce the number of builds and thus expedite the testing time, the compressors were assembled in a series of two-stage configurations. Some of those stages were used in two different builds: in one, they were preceded by the next stage of higher specific speed; and in the other, they were followed by the next stage of smaller specific speed. Uncertainties of the interstage temperature and pressure measurements, which could not be resolved during the closed loop testing, necessitated the creation of a method for reconstructing the characteristics of each of the two stages of each build, which would be based only on the overall measurements taken at the inlet and outlet flanges.
Using this iterative procedure, the individual stage characteristics of the new family of compressor stages were reconstructed and later applied to the performance prediction of many multistage production units of that family. The number of stages ranged from 2 to 8. Factory test results have shown very good agreement with the prediction.
Why an Engine Air Particle Separator (EAPS)?
Authors: Potts Joe Thomas 
Published: March 2015

The purpose of this technical paper is to describe how an Engine Air Particle Separator (EAPS) removes contaminant particles before they enter the gas turbine engine. Gas turbine engines perform poorly in air containing sand, volcanic ash, industrial pollutants, etc. Typical dirt related gas turbine malfunctions include:
• Erosion of the engine and air cycle machinery rotating components.
• Clogging and fouling of turbine section.
• Wear of oil wetted components caused by contaminated lubricants.
Contaminated air entering an EAPS is sent through a swirling motion induced by the vortex generator. This swirling motion causes the heavier dirt particles and water droplets to be thrown radially outward by centrifugal force so that they may be scavenged from the engine air intake.
This report will provide test results of helicopters with and without EAPS and describes the steps necessary to design an EAPS for various air vehicles and engines.
Combined Cycle Plants With Frame 9F Gas Turbines
Authors: Lugand P. , Parietti C. 
Published: March 2015

The new 200 MW-class MS 9001F gas turbines allow combined cycle plants to reach even higher output levels and greater efficiency ratings. Size factor and higher firing temperatures, with a 3-pressure level steam reheat cycle, offer plant efficiencies in excess of 53 %. Heat recovery steam generators have been designed to accommodate catalytic reduction elements limiting flue gas NOx emissions to as low as 10 ppm VD (15 % O2). A range of steam turbine models covers the different possible configurations.
Various arrangements based on the 350 or 650 MW power generation modules can be optimally configured to the requirements of each site.
The Use of Semi-Conductor Sensors for Blade Surface Pressure Measurement in a Model Turbine Stage
Authors: Ainsworth R. W. , Dietz A. J. , Nunn T. A. 
Published: March 2015

The development of semi-conductor sensors particularly aimed at gas turbine technology applications is outlined. Methods of manufacture and means of utilising some of the inherent advantages of this type of sensor are discussed.
A novel technique, where miniature sensors are attached directly to the surface where the measurement is required, is described. This technique combines a high surface density of measurement points with a high frequency response capability. Detailed tests of the sensor’s performance have been conducted and results obtained using this technology are presented. The performance tests include frequency response, base strain sensitivity, g sensitivity, and software temperature compensation schemes.
Finally, possible future applications for these techniques in gas turbine technology are outlined.
Endwall Losses and Flow Unsteadiness in a Turbine Blade Cascade
Authors: Adjlout L. , Dixon S. L. 
Published: March 2015

The purpose of this paper is to describe an investigation of the flow within and downstream of a turbine blade cascade of high aspect ratio. A detailed experimental investigation into the changes in the endwall boundary layer in the cascade (100deg camber angle) and total pressure loss downstream of the cascade was carried out. Flow visualisation was used in order to obtain detailed photographs of the flow patterns on the endwall and for exhibiting the trailing edge vortices. Pressure measurements were carried out using a miniature cranked Kiel probe for three planes downstream of the cascade, with two levels of turbulence intensity of the free-stream. Pressure distribution on the blade were measured at three spanwise locations, namely 4%, 12%, and 50% of the full-span from the wall. Hot wire anenometry combined with a spectrum analyser program was used to determine the frequencies of the flow oscillations.
The change in turbulence level of the free stream has a significant influence on all three pressure distributions. The striking difference between two of the pressure distributions is in the aft half of the suction side where the distribution with the lower turbulence intensity has the larger lift. The oil flow visualisation reveals what appears to be two separation lines within the passage and are believed to originate from the horseshoe vortex. The pitchwise-averaged total pressure loss coefficient increases with the distance of the measurement plane downstream of the cascade blades. A substantial part of this loss increase close to the wall is caused by the high rate of shear of the new boundary layer on the endwall.
MS 9001F: A New Advanced Technology 50 Hz Gas Turbine
Authors: Brandt D. E. , Colas M. 
Published: March 2015

Following a thorough market analysis, the MS 9001F heavy duty gas turbine has been designed using aerodynamic scaling based on the 60 Hz MS 7001F.
Effort put into the design has been shared by the engineering departments of ALSTHOM and GE.
This paper discusses the market surveys for large heavy duty gas turbines as well as the basis of design for the MS 9001F, which has been derived from the MS 7001F. Specifically discussed are the role of scaling, the design characteristics of the MS 7001F and the MS 9001F, the results of 7001F prototype testing, the test plan for the MS 9001F, plant lay out possibilities and ratings.
The MS 9001F gas turbine uses advanced aircraft engine technology in its design, with a rating based on a firing temperature of 1260°C (2300°F), which is 156°C (280°F) higher and with compressor inlet flow 50% greater than its predecessor, the MS 9001E.
Future of Combined-Cycle Plants in Belgium
Authors: Mathieu Philippe 
Published: March 2015

In this paper we investigate the possible penetration of combined-cycle plants in the Belgian electricity generation system after the Belgian Government has not considered as appropriate the construction of a next nuclear plant at the present time. First the characteristic features of the Belgian production capabilities are given. The share of gas turbines, turbojets and already existing combined-cycle plants and their operation modes are emphasized. Then, alternative options to nuclear energy are presented, i.e. repowering of existing plants and construction of new combined-cycle plants. The potentialities of gas turbines and CC plants as well as their future in Belgium are investigated.
Finally we discuss the equipment plan for the Belgian generation system proposed by the management committee of the electrical plant operators.
From the results of our research about repowering, gas turbines and new CC plants, we derive recommendations for the future production means in Belgium.
Determination of Fracture Origin in Ceramic Radial Rotor by Taking Photographs at Failure From Two or Three Directions
Authors: Kamiya Nobuo , Asai Mitsuru , Bessho Akinobu , Wada Shigetaka 
Published: March 2015

A technique involving taking moment photographs from two or three directions at failure of ceramic radial rotor was developed to determine the position of fracture origin of the radial rotor revolving at a high speed.
The position of the fracture origin of the silicon nitride radial rotor, 60mm in outer diameter and fabricated by injection molding, was demonstrated to be the fillet at the base of the shaft subjected to high stress. Furthermore, the dependence of cracking modes of rotors on the position of fracture origin was demonstrated using ceramic rotors with artificial flaws.
Development of Ceramic Engine Parts for Heat Insulated Engine
Authors: Kawamura Hideo 
Published: March 2015

In order to develop a ceramics engine with heat insulated combustion chambers, the strength of engine parts made of ceramics materials, design methods of the parts and triborogical features were studied for producing ceramics engine. In order to use the ceramics materials mainly Si3N4 with a suitable strength and fracture toughness, the correlation of strength and pore or flaw size or microstructures were investigated.
On the other hand, designing methods were studied by using the calculation results of F. E. M on the practical engine and the strength of ceramics. Also, we investigated the characteristics of triborogical factors on the test pieces made of ceramics materials.
In the result, we have achieved to produce the ceramics engine with a satisfactory durability and a lower friction through very severe tests.
Nonribosomal Peptides, Key Biocontrol Components for Pseudomonas fluorescens In5, Isolated from a Greenlandic Suppressive Soil
Authors: Michelsen Charlotte F. , Watrous Jeramie , Glaring Mikkel A. , Kersten Roland , Koyama Nobuhiro , Dorrestein Pieter C. , Stougaard Peter 
Published: March 2015

ABSTRACT

Potatoes are cultivated in southwest Greenland without the use of pesticides and with limited crop rotation. Despite the fact that plant-pathogenic fungi are present, no severe-disease outbreaks have yet been observed. In this report, we document that a potato soil at Inneruulalik in southern Greenland is suppressive against
Rhizoctonia solani
Ag3 and uncover the suppressive antifungal mechanism of a highly potent biocontrol bacterium,
Pseudomonas fluorescens
In5, isolated from the suppressive potato soil. A combination of molecular genetics, genomics, and matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) imaging mass spectrometry (IMS) revealed an antifungal genomic island in P. fluorescens In5 encoding two nonribosomal peptides, nunamycin and nunapeptin, which are key components for the biocontrol activity by strain In5
in vitro
and in soil microcosm experiments. Furthermore, complex microbial behaviors were highlighted. Whereas nunamycin was demonstrated to inhibit the mycelial growth of R. solani Ag3, but not that of
Pythium aphanidermatum
, nunapeptin instead inhibited P. aphanidermatum but not R. solani Ag3. Moreover, the synthesis of nunamycin by P. fluorescens In5 was inhibited in the presence of P. aphanidermatum. Further characterization of the two peptides revealed nunamycin to be a monochlorinated 9-amino-acid cyclic lipopeptide with similarity to members of the syringomycin group, whereas nunapeptin was a 22-amino-acid cyclic lipopeptide with similarity to corpeptin and syringopeptin.

IMPORTANCE
Crop rotation and systematic pest management are used to only a limited extent in Greenlandic potato farming. Nonetheless, although plant-pathogenic fungi are present in the soil, the farmers do not experience major plant disease outbreaks. Here, we show that a Greenlandic potato soil is suppressive against
Rhizoctonia solani
, and we unravel the key biocontrol components for
Pseudomonas fluorescens
In5, one of the potent biocontrol bacteria isolated from this Greenlandic suppressive soil. Using a combination of molecular genetics, genomics, and microbial imaging mass spectrometry, we show that two cyclic lipopeptides, nunamycin and nunapeptin, are important for the biocontrol activity of P. fluorescens In5 both
in vitro
and in microcosm assays. Furthermore, we demonstrate that the synthesis of nunamycin is repressed by the oomycete
Pythium aphanidermatum
. Overall, our report provides important insight into interkingdom interference between bacteria and fungi/oomycetes.
Deficiency of the Novel Exopolyphosphatase Rv1026/PPX2 Leads to Metabolic Downshift and Altered Cell Wall Permeability in Mycobacterium tuberculosis
Authors: Chuang Yu-Min , Bandyopadhyay Nirmalya , Rifat Dalin , Rubin Harvey , Bader Joel S. , Karakousis Petros C. 
Published: March 2015

ABSTRACT

Mycobacterium tuberculosis
can persist for decades in the human host. Stringent response pathways involving inorganic polyphosphate [poly(P)], which is synthesized and hydrolyzed by polyphosphate kinase (PPK) and exopolyphosphatase (PPX), respectively, are believed to play a key regulatory role in bacterial persistence. We show here that
M. tuberculosis
poly(P) accumulation is temporally linked to bacillary growth restriction. We also identify
M. tuberculosis
Rv1026 as a novel exopolyphosphatase with hydrolytic activity against long-chain poly(P). Using a tetracycline-inducible expression system to knock down expression of
Rv1026
(
ppx2
), we found that
M. tuberculosis
poly(P) accumulation leads to slowed growth and reduced susceptibility to isoniazid, increased resistance to heat and acid pH, and enhanced intracellular survival during macrophage infection. By transmission electron microscopy, the
ppx2
knockdown strain exhibited increased cell wall thickness, which was associated with reduced cell wall permeability to hydrophilic drugs rather than induction of drug efflux pumps or altered biofilm formation relative to the empty vector control. Transcriptomic and metabolomic analysis revealed a metabolic downshift of the
ppx2
knockdown characterized by reduced transcription and translation and a downshift of glycerol-3-phosphate levels. In summary, poly(P) plays an important role in
M. tuberculosis
growth restriction and metabolic downshift and contributes to antibiotic tolerance through altered cell wall permeability.

IMPORTANCE
The stringent response, involving the regulatory molecules inorganic polyphosphate [poly(P)] and (p)ppGpp, is believed to mediate
Mycobacterium tuberculosis
persistence. In this study, we identified a novel enzyme (Rv1026, PPX2) responsible for hydrolyzing long-chain poly(P). A genetically engineered M. tuberculosis strain deficient in the
ppx2
gene showed increased poly(P) levels, which were associated with early bacterial growth arrest and reduced susceptibility to the first-line drug isoniazid, as well as increased bacterial survival during exposure to stress conditions and within macrophages. Relative to the control strain, the mutant showed increased thickness of the cell wall and reduced drug permeability. Global gene expression and metabolite analysis revealed reduced expression of the transcriptional and translational machinery and a shift in carbon source utilization. In summary, regulation of the poly(P) balance is critical for persister formation in M. tuberculosis.