bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduction in Secondary Losses in Turbine Cascade Using Contoured Boundary Layer Fence
Authors: Deshpande Srikanth , Thern Marcus , Genrup Magnus 
Published: February 2015

Present work deals with reducing secondary losses in turbine cascade by using boundary layer fences in two ways. Firstly, to reduce the strength of vortex which is incident at the leading edge of airfoil and hence reduce the strength of horse shoe vortex, and secondly, to reduce the pressure gradient between the pressure side and the suction side in the flow passage region between airfoils. In previous works, the boundary layer fence followed the profile of airfoil. In this publication, boundary layer fence does not follow the profile of airfoil i.e stagger and camber of boundary fence is different when compared to airfoil.
A profiled boundary layer fence is proposed in the present work which reduces the incident vorticity and also reduces pressure gradient from pressure side to suction side. Such boundary layer fence was checked on T106 test cascade which is available as open literature. Numerical work is carried out using commercial software Ansys CFX. Viscous RANS simulations are carried out using k-ω SST turbulence model with yplus value around unity on all walls. Coefficient of secondary kinetic energy (CSKE) and Secondary Kinetic energy helicity (SKEH) are used as target functions. Total pressure loss is also monitored. All the three functions show a reduction in secondary loss. The strength of horse shoe vortex is reduced by the fence protruding in front of leading edge. The converging flow passage created by the fence near the pressure side of airfoil reduces the pressure gradient from pressure side to suction side. The total pressure loss was reduced by 1.5 % and CSKE was improved by 36 % when the boundary layer fence was adopted.
A Theoretical and Computational Analysis of the Bolted Joint: A Sensitivity Study of Temperature Effect on the Turbocharger Inlet Bolted Joint in Locomotive Engines
Authors: Khudhir Ali K. A. , Aggarwal Mahesh C. , Sirak Michael , Panza Michael J. 
Published: February 2015

The bolted joint is a very popular method of fastening together different components and one of the most important factors of machine design. Any mechanical failure of the bolted joint in rail industries can affect their financial, safety, and public confidence. In this paper, the primary objective was to create a bolted joint model to analyze the behavior of the turbocharger inlet bolted joint on a GE Transportation engine under room and working temperature. Theoretical and computational analyses investigations have been undertaken to determine the behavior of a turbocharger inlet bolted joint at room and working temperature based on VDI 2230 Part 1 and SR1+ program. Also, the reliability and validity of turbocharger inlet bolts were evaluated depending on their safety factors. A computational analysis has been performed for both structural and thermo structural loads that applied to the turbocharger inlet bolted joint.
The results obtained show that the stresses on the bolted joint increased 25% at working temperature. Also, the strength of the bolted joint has a direct relationship with amount of tightening torque applied to the bolt while the position of the bolts has a major effect on the behavior of the bolted joint. In addition, the analysis showed that the turbocharger inlet bolted joint behaved differently depending on the loads type. The study also confirmed that the preliminary design had reduced margin at working temperature, and additional design modifications were required. It was determined that the loosening of the bolted joint and insufficient preload were the main reasons of failure.
Effect of Manufacturing Tolerances on the Turbine Blades
Authors: Kolmakova Daria , Baturin Oleg , Popov Grigorii 
Published: February 2015

The quantification of geometric and physical variables uncertainty impact on turbomachinery row workflow was conducted using several untwisted airfoil cascades of axial turbine nozzle blades with uniform section throughout the channel height.
Profile loss coefficient, mass flow parameter, outlet flow angle were accepted as controlled performance criteria.
The series of computational calculations were carried out for these cascades. The first group of calculations was aimed at the identification of the impact of geometric parameters uncertainty on nozzle blades parameters. The second group - at identifying the studied parameters depending on the flow parameters changes that are used as boundary conditions in the simulation.
The obtained results showed that initial data uncertainty in CFD calculations has a significant impact on the obtained quantitative estimates. The difference between calculated data modified in accordance with the geometry technological tolerances and workflow parameters measurement error may exceed 5% by value of the considered criteria.
Bolted Joint Simulation Techniques in Gas Turbine Components
Authors: Jalammanavar Kuberappa , Kasina Lakshman , Srinivasan Raghavan Kotur , Shivaramaiah Prasanna , Kuncham Ramakrishnayya Gupta 
Published: February 2015

Bolted joints are integral part of many industrial applications such as the most simple to the most complex and expensive machinery. They provide the primary means of connecting components. These joints play an important role in the integrity and durability of the systems. Bolted joint simulation is one of the important aspects of designing and evaluating any assembly. FE modeling simulation for bolted joint pose limitations in terms of simulating the real life bolted joint behavior. Simulation should be accurate enough but also simple enough to solve model faster.
There are many practices exist that helps the analyst to simulate the bolted joint. These practices need to be reviewed in detail and evaluated against high fidelity 3D finite element model. The physical behavior of the bolted joint can be simulated accurately by 3D bolted joint with preload, friction and contact between mating parts. The detail 3D modeling of bolted joint for the complex assembly models with multiple bolted joints will be very expensive in terms of computational cost and time. This study presents multiple methods of bolted joints simulation using ANSYS® 12.1[1]. The bolted joint model simulated using beam element is very effective in terms of computational cost, time and memory usage for complex assembly models. Bolted joint simulation with threads happens to be the most rigorous with the results and this method is a yardstick. Other approaches are evaluated from points of view of accuracy and effort effectiveness. This paper also presents the bolted joint analysis best practices on using above methods for various stages of component design. Typical gas turbine flange is taken for case study.
Experimental Investigations on Heat Transfer Enhancement in a Horizontal Tube Using Converging and Diverging Conical Strips
Authors: Somanchi Naga Sarada , Rangisetty Sri Rama Devi , Bellam Sudheer PremKumar , Gugulothu Ravi , Bellam Samuel 
Published: February 2015

The present work deals with the results of the experimental investigations carried out on augmentation of turbulent flow heat transfer in a horizontal circular tube by means of tube inserts, with air as working fluid.
Experiments were carried out initially for the plain tube (without tube inserts). The Nusselt number and friction factor obtained experimentally were validated against those obtained from theoretical correlations.
Secondly experimental investigations using six kinds of tube inserts namely Rectangular bar with diverging conical strips, Rectangular bar with converging conical strips, Rectangular bar with alternate converging diverging conical strips, Rectangular bar with holes and diverging conical strips, Rectangular bar with holes and converging conical strips and Rectangular bar with holes and alternate converging diverging conical strips were carried out to estimate the enhancement of heat transfer rate for air in the presence of inserts. The Reynolds number ranged from 8000 to 19000. In the presence of inserts, Nusselt number and pressure drop increased, overall enhancement ratio is calculated to determine the optimum geometry of the tube insert.
Based on experimental investigations, it is observed that, the enhancement of heat transfer using Rectangular bar with diverging conical strips is more effective compared to other inserts.
Prediction of Gas Turbine Oil Scoop Capture Efficiency
Authors: Prasad Santosh Kumar , Sangli Pradeep , Buyukisik Osman , Pugh Dave 
Published: February 2015

The lubrication system in a gas turbine engine is akin to the human blood circulatory system. Providing right quantities of oil to the right components for cooling and lubrication is the primary function of the lubrication system. In the current analysis, at the downstream end of the lube oil supply line, a stationary oil nozzle sprays a jet of oil to a high speed rotating component called an oil scoop. The function of the oil scoop which rotates at speeds usually greater than 10000 RPM is to ‘Scoop’ or capture the oil and provide an under race oil transfer mechanism to the bearings rotating especially at such high speeds. If the oil capture is less than required by the downstream bearing components, it could lead to diminished bearing lives in the gas turbine.
The oil scoop consists of two or more blades that are angled with respect to the radius of the Scoop to provide an entry to the oil jet. The ‘window’ of open space between the blades is important to capture the oil. The ratio of quantity of oil captured to the total oil sprayed on to oil scoop is termed as the oil capture efficiency. Several parameters like oil nozzle distance from the blade tip, spray characteristics, jet velocity, number of blades, blade angle, window width, rotational speeds, oil temperature etc. are important factors that determine the capture efficiency of the oil scoop. Prior to the availability of efficient CFD methodologies, it was extremely difficult to develop an oil scoop capture efficiency predictive tool that involves a complex 3D fluid flow from a stationary to a rotating component. The typical Reynolds number of the jet is around 13000 and the oil scoop tip speeds of the order of Mach 0.2 to 0.4. To evaluate various scoop design configurations and enhancements, a transient CFD methodology was developed using multiphase Volume of Fluid approach available in FLUENT® software. In this paper a technique or process is described and demonstrated to simulate the right ‘periodic’ nature of the oil capture and transfer mechanism. It is shown that the CFD methodology described compares well with experimental data.
This robust CFD methodology predicts the complex 3D flow with sufficient accuracy and has the potential to be used to optimize the geometry for maximum oil capture efficiency of oil scoops in gas turbine lubrication system. Significant reduction of costly experiments is also an important benefit of developing this predictive methodology.
Structural Assessment of Torque Converter at Operating Conditions: A Numerical Study
Authors: Shivaramaiah Subbaramu , Banthia Vinod K. , Kumar S. M. Vijay 
Published: February 2015

A single stage torque converter consists of three elements — pump, stator and turbine. Pump and turbine are coupled by transmission fluid. Unlike a fluid coupling, however, a torque converter is able to multiply torque when there is a substantial difference between input and output rotational speed, thus providing the equivalent of a reduction gear. During its operation all these elements are subjected to centrifugal load, fluid pressure load and heat generated in transmission fluid. Overloading a converter can result in several failure modes, some of them potentially dangerous in nature: ballooning, blade deformation and defragmentation, overheating.
In the current work a single stage torque converter, was modelled and analysed numerically for evaluating stress distribution and deformation. The engine operating speed at 2000 rpm was considered for analysis. For static analysis of torque converter components centrifugal load and fluid pressure load were considered. Analysis was carried out for six different speed ratios varying from zero to one. Variation of principal stresses (hoop stress and radial stress) and von-Mises stress has been discussed. Maximum stresses are found to be in pump at speed ratio of one and in turbine at speed ratio of zero. Maximum stresses are at shell core that is near to hub. Blade deformation in pump is maximum at coupling phase and in turbine it is maximum at stall condition. From these results it helps to predict the failure of torque converter components under different operating conditions.
Glycoprotein-Based Enzyme-Linked Immunosorbent Assays for Serodiagnosis of Infectious Laryngotracheitis
Authors: Kanabagatte Basavarajappa Mallikarjuna , Song Haichen , Lamichhane Chinta , Samal Siba K. 
Published: February 2015

ABSTRACT
For detection of infectious laryngotracheitis virus (ILTV) antibody, glycoprotein B-, C-, and D-based enzyme-linked immunosorbent assays (B-, C-, and D-ELISAs, respectively) were developed. The B- and D-ELISAs showed enhanced detection of anti-ILTV antibodies in infected chickens compared to that of the commercial ELISA. Furthermore, the D-ELISA was efficient in detecting seroconversion with vectored vaccine, using recombinant Newcastle disease virus (rNDV) expressing glycoprotein D (gD) as the vaccine vector.
Presence of Virulent Newcastle Disease Virus in Vaccinated Chickens in Farms in Pakistan
Authors: Rehmani Shafqat Fatima , Wajid Abdul , Bibi Tasra , Nazir Bushra , Mukhtar Nadia , Hussain Abid , Lone Nazir Ahmad , Yaqub Tahir , Afonso Claudio L. 
Published: February 2015

ABSTRACT

One year after a virulent Newcastle disease virus (vNDV) outbreak in Pakistan, the causative strain was present in vaccinated chickens of multiple farms despite the existence of high-average NDV-specific antibody titers (>4.75 log
2
). The data suggest a possible role of vaccinated birds as reservoirs of vNDV.
Efficient Isolation of Swine Influenza Viruses by Age-Targeted Specimen Collection
Authors: Ozawa Makoto , Matsuu Aya , Yonezawa Kouki , Igarashi Manabu , Okuya Kosuke , Kawabata Toshiko , Ito Kimihito , Tsukiyama-Kohara Kyoko , Taneno Akira , Deguchi Eisaburo 
Published: February 2015

ABSTRACT
The control of swine influenza virus (SIV) infection is paramount for increasing the productivity of pig farming and minimizing the threat of pandemic outbreaks. Thus, SIV surveillance should be conducted by region and on a regular basis. Here, we established a microneutralization assay specific for SIV seroprevalence surveillance by using reporter gene-expressing recombinant influenza viruses. Growth-based SIV seroprevalence revealed that most sows and piglets were positive for neutralizing antibodies against influenza viruses. In contrast, the 90-day-old growing pigs exhibited limited neutralizing activity in their sera, suggesting that this particular age of population is most susceptible to SIV infection and thus is an ideal age group for SIV isolation. From nasal swab specimens of healthy pigs in this age population, we were able to isolate SIVs at a higher incidence (5.3%) than those of previous reports. Nucleotide sequencing and phylogenetic analysis of the hemagglutinin (HA) genes revealed that the isolated SIVs have circulated and evolved in pigs but not have been recently introduced from humans, implying that a large number of SIV lineages may remain “undiscovered” in the global porcine populations. We propose that the 90-day-old growing pig-targeted nasal swab collection presented in this study facilitates global SIV surveillance and contributes to the detection and control of SIV infection.
Single-Molecule Arrays for Ultrasensitive Detection of Host Immune Response to Dengue Virus Infection
Authors: Gaylord Shonda T. , Abdul-Aziz Sama , Walt David R. 
Published: February 2015

ABSTRACT
Dengue virus serotype 2-positive plasma was applied to two indirect single-molecule arrays (Simoas) for the detection of anti-dengue virus IgG and IgM. The Simoas were 1,000 and 10,000 times more sensitive than enzyme-linked immunosorbent assays (ELISAs) for the detection of IgG and IgM, respectively. Using Simoas, serology may be used for the detection of dengue virus infection in the acute phase.
Gene Expression Profiling of Burkholderia cenocepacia at the Time of Cepacia Syndrome: Loss of Motility as a Marker of Poor Prognosis?
Authors: Kalferstova Lucie , Kolar Michal , Fila Libor , Vavrova Jolana , Drevinek Pavel 
Published: February 2015

ABSTRACT

Cepacia syndrome (CS) is a fatal septic condition that develops in approximately 20% of cystic fibrosis (CF) patients chronically infected with the
Burkholderia cepacia
complex (Bcc). The most common causative agent is
Burkholderia cenocepacia
, a clinically dominant Bcc species that contains the globally distributed epidemic strain sequence type 32 (ST32). Using microarrays, we compared the transcriptomes of ST32 isolates from the bloodstream at the time of CS with their sputum counterparts recovered 1 to 2 months prior to the development of CS. Global gene expression profiles of blood isolates revealed greater activities of the virulence genes involved in the type III secretion system, the bacterial exopolysaccharide cepacian, and quorum sensing, while reduced expression was demonstrated for flagellar genes. Furthermore, a nonmotile phenotype (as evaluated by a swimming motility assay) was identified in blood isolates from 6 out of 8 patients with CS; this phenotype was traceable to 24 months prior to the onset of CS. Loss of motility was not observed in any of the 89 ST32 isolates recovered over the course of chronic infection from 17 patients without CS. In conclusion, the gene expression of Bcc bacteria disseminated during CS has been elucidated for the first time. This study demonstrated marked differences at the transcriptome level between isogenic ST32 isolates that are attributable to the stage and site of infection. The finding of a nonmotile
B. cenocepacia
isolate may serve as a warning sign for the development of CS in the near future.
Systematic Serological Testing for Hepatitis E Virus in Kidney Transplant Recipients
Authors: Moal Valérie , Legris Tristan , Motte Anne , Vacher-Coponat Henri , Fages Lucie , Jourde-Chiche Noémie , Borentain Patrick , Jaubert Dominique , Gerolami René , Colson Philippe 
Published: February 2015

ABSTRACT
Hepatitis E virus (HEV) genotype 3 is endemic in Europe and hyperendemic in southern France. Recent reports of a high prevalence of HEV RNA in blood donations and in culinary specialties from this geographical area confirmed the endemicity of HEV and sources of viral transmission in this geographical area. HEV causes acute and chronic hepatitis in solid organ transplant recipients. Since March 2012, we have implemented systematic HEV serological testing in our cohort of kidney transplant recipients (KTRs) in Marseille in southeastern France. The aim of our study was to assess HEV exposure in this cohort between March 2012 and May 2014. During these 27 months, we found that 39% of the patients who underwent kidney transplantation had an anti-HEV IgG response using a sensitive microplate enzyme immunoassay. This seroprevalence was approximately 43% at both 1 and 8 years after, using the same assay. In addition, systematic HEV serological testing detected 6 cases of HEV infection among 578 KTRs (1%) during the 27 months of the study, with 5 at an acute stage and 1 at a chronic stage. In conclusion, continuous HEV monitoring in this population is useful for better understanding the epidemiology of HEV in France, because these patients are a well-monitored population. Moreover, HEV monitoring in KTRs is clinically relevant because HEV represents a clinical threat in these patients. Nevertheless, HEV serological testing may be more fruitful for identifying HEV infections when performed in cases of biological liver abnormalities than when performed systematically.
Impact of Revised Cefepime CLSI Breakpoints on Escherichia coli and Klebsiella pneumoniae Susceptibility and Potential Impact If Applied to Pseudomonas aeruginosa
Authors: Hamada Yukihiro , Sutherland Christina A. , Nicolau David P. 
Published: February 2015

ABSTRACT

The CLSI reduced the cefepime
Enterobacteriaceae
susceptibility breakpoint and introduced the susceptible-dose-dependent (S-DD) category. In this study, MICs were determined for a Gram-negative collection to assess the impact of this change. For
Enterobacteriaceae
, this resulted in <2% reduction in susceptibility, with 1% being S-DD. If applied to
Pseudomonas aeruginosa
, the % susceptibility (%S) dropped from 77% to 43%, with 34% being S-DD. The new breakpoints did little to the
Enterobacteriaceae
%S, but for
P. aeruginosa
, a profound reduction was seen in %S. The recognition of a S-DD response to cefepime should alert clinicians to the possible need for higher doses.
A New Real-Time Reverse Transcription-PCR Assay for Detection of Human Enterovirus 68 in Respiratory Samples
Authors: Piralla Antonio , Girello Alessia , Premoli Marta , Baldanti Fausto 
Published: February 2015

ABSTRACT
A global reemergence of human enterovirus 68 (EV-D68) associated with severe respiratory illness occurred in 2014. We developed and validated an EV-D68-specific real-time reverse transcription-PCR (RT-PCR) for the detection of EV-D68 in respiratory samples. The rapid diagnosis of EV-D68 may contribute to better management of EV-D68 infections.