bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in malaria care seeking and dispensing outcomes for adults and children attending drug vendors in Nasarawa, Nigeria
Authors: Liu Jenny , Isiguzo Chinwoke , Sieverding Maia
Published: April 2015

Objectives

To characterise the differences in care seeking behaviour and dispensing outcomes between adults and children purchasing drugs for malaria at retail shops in Nigeria.

Methods

In Nasarawa State, retail drug shops were enumerated and a subset of those stocking antimalarials were selected as study sites and surveyed. Customers exiting shops after purchasing antimalarial drugs were surveyed and tested with a malaria rapid diagnostic test. Sick adults and caregivers accompanying sick children were eligible, but individuals purchasing drugs for a sick person that was not present were excluded. Multivariate regression analysis was used to identify the correlates of care seeking and the quality of interaction at the shop.

Results

Of 737 participants, 80% were adults and 20% were children (under age 18). Caregivers of sick children were more likely to obtain a prescription prior to attending a drug retailer than adults seeking care for themselves and waited a shorter time before seeking care. Caregivers of sick children were also more likely than sick adults to have been asked about symptoms by the retailer, to have been given an examination, and to have purchased an ACT. Fewer than half of respondents had purchased an ACT. Only 14% of adults, but 27% of children were RDT‐positive; RDT‐positive children were more likely to have had an ACT purchased for them than RDT‐positive adults.

Conclusions

Children with suspected malaria tend to receive better care at drug retailers than adults. The degree of overtreatment and prevalence of dispensing non‐recommended antimalarials emphasise the need for routine diagnosis before treatment to properly treat both malaria and non‐malaria illnesses.
In vitro study of platelet function confirms the contribution of the ultraviolet B (UVB) radiation in the lesions observed in riboflavin/UVB‐treated platelet concentrates
Authors: Abonnenc Mélanie , Sonego Giona , Crettaz David , Aliotta Alessandro , Prudent Michel , Tissot Jean‐Daniel , Lion Niels
Published: April 2015

BACKGROUND

Platelet inactivation technologies (PITs) have been shown to increase platelet storage lesions (PSLs). This study investigates amotosalen/ultraviolet (UV)A‐ and riboflavin/UVB‐induced platelet (PLT) lesions in vitro. Particular attention is given to the effect of UVB alone on PLTs.

STUDY DESIGN AND METHODS

Buffy coat–derived PLT concentrates (PCs) were treated with amotosalen/UVA, riboflavin/UVB, or UVB alone and compared to untreated PCs throughout storage. In vitro PLT function was assessed by blood gas and metabolite analyses, flow cytometry–based assays (CD62P, JC‐1, annexin V, PAC‐1), hypotonic shock response, and static adhesion to fibrinogen‐coated wells.

RESULTS

In our experimental conditions, riboflavin/UVB‐treated PCs showed the most pronounced differences compared to untreated and amotosalen/UVA‐treated PCs. The riboflavin/UVB treatment led to a significant increase of anaerobic glycolysis rate despite functional mitochondria, a significant increase of CD62P on Day 2, and a decrease of JC‐1 aggregates and increase of annexin V on Day 7. The expression of active GPIIbIIIa (PAC‐1) and the adhesion to fibrinogen was significantly increased from Day 2 of storage in riboflavin/UVB‐treated PCs. Importantly, we showed that these lesions were caused by the UVB radiation alone, independently of the presence of riboflavin.

CONCLUSION

The amotosalen/UVA‐treated PCs confirmed previously published results with a slight increase of PSLs compared to untreated PCs. Riboflavin/UVB‐treated PCs present significant in vitro PSLs compared to untreated PCs. These lesions are caused by the UVB radiation alone and probably involve the generation of reactive oxygen species. The impact of these observations on clinical use must be investigated.
Fatigue Life Improvement of Holed Plates Made of an Innovative Medium C Micro-Alloyed Steel by Local Plastic Deformation
Authors: Croccolo Dario , De Agostinis Massimiliano , Olmi Giorgio , Ceschini Lorella , Morri Alessandro
Published: April 2015

This paper deals with the influence of local plastic deformation on the fatigue strength of holed plates manufactured with an innovative medium-carbon micro-alloyed steel with high silicon content (hi-Si MCM). Local deformation around the hole is achieved by means of an interference fitted pin. The effect was investigated both experimentally and numerically. Microstructural characterization, hardness, and tensile tests were carried out first. Tension–tension fatigue tests were performed under two different conditions: open-hole (OH) specimens and specimens with a press fitted pin with 0.6% nominal specific interference. A 2D elastic–plastic finite element analyses (FEAs) investigation was done as well, in order to analyze the stress field in the vicinity of the hole. The stress history and distribution in the neighborhood of the hole indicate a significant reduction of the stress amplitude produced by the external loading (remote stress) when a residual stress field is generated by the pin insertion. In fact, experimental stress-life (SN) curves pointed out increased fatigue strength of the interference fit specimens, compared with the OH ones. Finally, scanning electron microscope (SEM) analyses of the fractured fatigue specimens were carried out, in order to investigate the mechanisms of failure and to relate them to the peculiar microstructural features that characterize this innovative steel.
Establishing Cruise-Engine Cycle Payoffs for a Supersonic VSTOL Aircraft
Authors: Cyrus J. D. , Piscopo P. F. , Lazarick R. T.
Published: April 2015

Engine-aircraft-mission studies have been conducted by the Navy to establish changes in the weight and performance of supersonic VSTOL aircraft resulting from changes in the main cruise engine configuration, cycle characteristics, and complexity. The effects of engine component efficiency variations were quantified by a sensitivity analysis which identified performance changes on four different missions for a single engine aircraft. Studies of a twin engine aircraft with four different propulsion system configurations established the impact of changes in various cycle parameters on aircraft takeoff gross weight for the same three missions and identified thermodynamic and physical constraints for the cycles.
Design of Turbo Machine Set for Fluid Catalytic Cracking Plant and its Shop-Testing Under Full-Load Conditions
Authors: Turanskyj L. , Woelk G.-U.
Published: April 2015

In fluid catalytic cracking plants, heavy hydrocarbons are converted into low-boiling point products. The highly developed technology of this process makes it particularly suitable for the handling of heavy fractions and thus for energy economy in the future. Starting from a concise description of the energy recovery system, this paper details the design features of a turbo machine set for an FCC plant, with the emphasis on the design of the 4-stage 12,000 kW process gas expander. Since this expander incorporates new design features, an extensive test programme was carried out at a heavy turbomachinery test facility, where, in addition to testing the individual machine units under full-load conditions, a string test of the complete turbo machine set was performed under hot-gas conditions.
Low NOx Combustion Systems for Burning Heavy Residual Fuels and High-Fuel-Bound Nitrogen Fuels
Authors: White D. J. , Batakis A. , LeCren R. T. , Yacobucci H. G.
Published: April 2015

The work described in this paper is a part of the Department of Energy/Lewis Research Center (DOE/LeRC) “Advanced Conversion Technology” (ACT) project. The program is a multiple contract effort with funding provided by the Department of Energy and technical program management provided by NASA. LeRC. Environmentally acceptable operation with minimally processed petroleum based heavy residual and coal derived synthetic fuels requires advanced combustor technology. The technology described in this paper was developed under the DOE/ NASA Low NOx Heavy Fuel Combustor Concept Program (Contract DEN3-145). Novel combustor concepts were designed for dry reduction of thermal NOx, control of NOx from fuels containing high levels of organic nitrogen, and control of smoke from low hydrogen content fuels. These combustor concepts were tested by burning a wide variety of fuels including a middle distillate (ERBS), a petroleum based heavy residual, a coal derived synthetic (SRC-II), and various ratios of blends of these fuels.
The Use of Multi-Channel Radio Telemetering Techniques for Stress and Temperature Measurements in Gas Turbine Rotating Components
Authors: We-shung W. , Wen-hu Y. , Wen-fwu L.
Published: April 2015

This paper gives a short account of and evaluates a PPM-AM modulation time-division multi-channel telemetry system. With this system it is possible to simultaneously measure seven channels of vibration signals (strain and frequency data) and investigate the phase and strain relationship between the component parts in the blade-disk system coupled vibrations. A description is given of the seven-channel FM modulation time-division multiplex telemetry system for the acquisition of turbine disk static stress field and temperature field data and the operating technique of thermistors and high-temperature strain gauges.
A System to Measure the Response of a High-Speed Rotor to a Sudden Imbalance
Authors: Trippett R. J.
Published: April 2015

A unique rotor dynamic data acquisition system is described to control the gathering and display of rotor displacement data measured at rotor speeds up to 70 000 r/min. The first published results measured with this system are demonstrated with plots of measured transient shaft motion after a sudden increase in shaft imbalance at speeds up to 44 500 r/min. The displacements of the rotor in the forms of Lissajous plots with and without a squeeze film damper are presented at four axial shaft locations below and above the shafts critical speeds. The blade-loss, dynamic test rig is also described.
Controlled Combustion of a Varying Low-Btu Coal-Derived Gas
Authors: Carpenter L. K. , Nakaishi C. V. , Bird J. D. , Loth J. L.
Published: April 2015

As a part of the United States Department of Energy’s High Temperature Turbine Technology Program, the Morgantown Energy Technology Center is participating in a Ceramics Corrosion/Erosion Materials Study. The objective is to create a technology base for ceramic materials for use in stationary gas power turbines operating in a high-temperature environment produced by combustion of low-caloric, coal-derived gas. Dynamic and Static Test facilities are designed and installed which have the capability to burn a varying low-caloric, coal-derived fuel gas in a controlled manner. This paper gives a description of METC’s design philosophies in developing these combustion test facilities.
The Performance of Portable Evacuation Compressors in Gas Transmission Service
Authors: Hladun A. R. , Wong F. , Dunn S. A.
Published: April 2015

As part of an extensive energy conservation program, Nova, an Alberta Corporation has purchased a portable evacuation or pulldown compressor. This unit can save much of the natural gas that was previously vented to atmosphere when sections of line were shut down for construction, maintenance or repair. In December, 1979 the company placed into service a 3000-kW pulldown package based upon an eight-stage intercooled centrifugal compressor powered by a two-shaft gas turbine. The unit is a complete trailer-mounted compressor station that can be set-up at a pipeline block-valve in only 4 hr. The pulldown can evacuate the isolated line section down to 1/5 of the original pressure, thereby saving some 75 percent of the high pressure gas. This paper will examine the advantageous economics of the pulldown compressor as well as outline its salient design and operating characteristics.
Equivalent Performance Testing of Multi-Section Compressors
Authors: Strite M. A. , Samurin N. A.
Published: April 2015

Equivalent performance testing of multi-section compressors has largely been ignored by the various test codes. Existing code methods have been modified and adapted for testing multi-section compressors by the manufacturers and users. The performance testing of two types of multi-section units — the externally cooled and the sideload compressor — are discussed here. Each compressor type has had specific test difficulties that require identification and resolution. Prior to the start of testing, an overview of the problems, along with some solutions, is presented.
Blading Heat Transfer Considerations in a Reheat-Gas-Turbine Combined Cycle
Authors: Jenkins P. E. , Rice I. G.
Published: April 2015

A brief presentation of the basic heat transfer equations for blade cooling is presented. Various cooling schemes have been developed over the past twenty years utilizing air as the cooling fluid. The mathematical models have subsequently predicted cooling schemes for the air cooling with little consideration for two phase fluids. This paper is written to describe the research needs for utilizing steam as a cooling fluid in a reheat-gas-turbine combined cycle system. The basic heat transfer equations are derived and discussed with regard to implementing the steam blanket cooling mechanism. The steam injection and dispersion problem is discussed, along with the need for future research in using steam as a viable cooling technique.
Materials Exposure Test Facilities for Varying Low-Btu Coal-Derived Gas
Authors: Nakaishi C. V. , Carpenter L. K. , Hawkins L. W.
Published: April 2015

As a part of the United States Department of Energy’s High Temperature Turbine Technology Readiness Program, the Morgantown Energy Technology Center (METC) is participating in a Ceramics Corrosion/Erosion Materials Study. The objective is to create a technology base for ceramic materials for use in stationary gas power turbines operating in a high-temperature environment produced by combustion of low-caloric coal-derived gas. METC facilities have been designed, fabricated and will be operated simultaneously exposing ceramic materials dynamically and statically to products of combustion of a coal-derived gas. This paper gives a description of the test facilities which have the capability to burn a varying low-caloric gas.
Strengthening Mechanisms and Process Controls for Super Waspaloy
Authors: Couts W. H. , Biederman R. R.
Published: April 2015

Super Waspaloy is an empirically derived thermomechanically processed version of Waspaloy. Microstructures were evaluated at steps in the hammer forge and heat treat sequence to study how the initial structure is derived. Foils taken from hot tensile, stress rupture, and elevated temperature low cycle fatigue bars were examined by transmission electron microscopy after exposure to temperature and stress. The purpose was to discover the microstructural features resistant to dislocation movement and to seek clues for further improvement of the alloy.
Effect of Blade Stagger Angle on Performance of a Transonic Compressor With Low Hub-Tip Ratio
Authors: Chun Zhao Shi , Qin Ma Shu , Long Wang Zhao
Published: April 2015

The effect of blade stagger angle on the performance of a transonic compressor with low hub-tip ratio is presented in the paper. Because the original single stage compressor failed to achieve the design target, tests were conducted on the compressor with the blades twisted and with the stagger angle reduced. The results of these tests indicate that at the design speed and mass flow, the pressure ratio is 1.339, the efficiency is 0.864, which is 2.2 percent better than the design value and 5 percent better than that of the original single stage. At the same time, the discharge total pressure and temperature profiles are improved substantially. The unevenness of the total pressure profile decreases from 18 to 7 percent and that of the total temperature from 53 to 18 percent.
Re-Examination of Design Criteria for Natural Gas Compressorstation “Ravenstein”: Holland
Authors: Van Dijk J. J. Th. , Klijn A. J.
Published: April 2015

During the initial years of Gasunie’s existence, the early 60’s, a projection was made for the power required in various compressorstations in the grid. This projection was updated periodically and this paper reviews the 1977 update, focussing on the Ravenstein compressorstation. The main subject of the paper is the development of the design criteria for this update and the comparison with the reality of the 1979/1980 pumping season. It may be stated that the actual conditions of the pumping season have justified the selection of the criteria.
A Market Research Effort Leading to the Development of a High Efficiency 10,000 shp Gas Turbine System
Authors: Frankfort K. , Rich J.
Published: April 2015

This paper describes the market research efforts which established the performance parameters, the design criteria and the product specification for a new 10,000 shp regenerative cycle gas turbine system which incorporates a two-stage intercooled centrifugal compressor and features a thermal efficiency which exceeds 43 percent.
Development of FT9 Marine Gas Turbine
Authors: Groghan D. A. , Miller C. L.
Published: April 2015

The FT9 Marine Gas Turbine development program was initiated in August 1973 by the Naval Sea Systems Command to fulfill, in part, the requirement for a family of gas turbine engines ranging in power from 1000 to 30,000 hp. The FT9 satisfied the requirement to develop a 30,000 hp class marine gas turbine. The FT9 is a derivative of the Pratt & Whitney Aircraft JT9D engine, which powers Boeing 747, DC-10 and A300 aircraft, and of the FT4 industrial gas turbine engine. The FT9 specification also required development of an on-line engine condition monitoring system. A rigorous development test program showed the FT9 has met all specified U.S. Navy requirements and demonstrated its suitability for use in U.S. Navy combatant ships.
Preliminary Design of Dry Cooling Tower for the Closed Cycle Gas Turbine HTGR
Authors: Montakhab A.
Published: April 2015

Because of its relatively high coolant temperature, the closed cycle gas turbine HTGR is well adapted to dry cooling and its waste heat can be rejected with relatively low cost. The preliminary design of natural-draft dry cooling towers for a 1200 MW(e) GT-HTGR is presented. The effects of air approach velocity, capacity rates of air and water mediums, and number of heat exchanger cross flow passes on salient tower and heat exchanger dimensions are studied. Optimum tower designs are achieved with three cross flow passes for the heat exchanger, resulting in a simultaneous minimization of tower height, heat exchanger surface area and circulating water pumping power. Four alternative tower designs are considered and their relative merits are compared. It is concluded that the 1200 MW(e) plant can be cooled by a single tower design which is well within the present state of the natural-draft dry cooling tower technology. In comparison, the fossil-fired or HTGR steam plants of the same output is shown to need three such towers.
Small Gas Turbine With Large Parabolic Dish Collectors
Authors: Bammert K. , Sutsch A. , Simon M. , Mobarak A.
Published: April 2015

An alternative solution for solar energy conversion to the heliostat-tower and solar farm (parabolic trough) concept is presented in the form of large parabolic dish collectors using small high temperature gas turbines for producing electricity from solar thermal energy. A cost and efficiency comparison for the different solar thermal power plants has shown that the large parabolic dish with gas turbine set is a superior system design especially in the net power range of 50 to 2000 kW. The important advantages of the large parabolic dish concept are discussed. For the important components such as the gas turbo converter, the receiver and the parabolic dish collector, design proposals for economic solutions are presented. An advanced layout for a 250-kW gas turbo converter with recuperator is presented in detail.
Experimental Investigation of a Low Hub-to-Tip Ratio Single Stage Transonic Fan
Authors: Yu-bing Wei , Bao-chang Dong , Guei-xiang Zhang
Published: April 2015

A preliminary analysis of a single-stage transonic fan with a hub-to-tip ratio of 0.385 is presented in this paper. The flow field design computer program and the parameter selection of the fan parameters are reviewed. The modifications which should be made to improve the performance of the fan are pointed out. The experimental results demonstrate that the overall performance design goals of the fan have been achieved at design speed and flow rate. But fan discharge total pressure and total temperature gradients still exist efficiency is poor at the hub and tip regions. Therefore the single stage fan is not suitable for use as an inlet stage. The main reason for the problems mentioned above are the inaccurate calculation of flow field and inadequate selection of design parameters.
Carbon/Carbon Components for Advanced Gas Turbine Engines
Authors: Danis L. , Cruzen S. , Schimmel W.
Published: April 2015

A preliminary assessment of carbon/carbon fiber/matrix composites for extreme temperature limited life service in small gas turbine engines has been completed. Spin tests of available disks were conducted, along with structural design micromechanical analyses of tested specimens and conceptual variants. Many specific strength values at ambient temperatures were found higher than those of presently used metals. Since these values increase as temperatures are elevated, a significant advantage is provided over contemporary and advanced turbine wheel materials. A major advantage of C/C composite over monolithic ceramic is a relative absence of defect sensitivity, brittleness, or rapid fracture progression. Experiments and studies were conducted to provide carbon/carbon bodies with state-of-the-art oxidation and erosion protection. Silicon carbide coated specimens show required promising static oxidation resistance for target engine mission life. Simulated dynamic end use tests have yet to be completed. It is recommended that further programs on carbon/carbon composite turbine components be conducted immediately to address coating refinement, component design, development of appropriate fiber architecture, and characterization of those architectures which result in acceptable service properties on tested components.
Studies of Full-Coverage Film Cooling: Part 1 — Cooling Effectiveness of Thermally Conductive Wall
Authors: Kasagi N. , Hirata M. , Kumada M.
Published: April 2015

The combined heat transfer/heat conduction tests were performed by adopting brass and acrylic resin as a material for the full-coverage film-cooled wall. The 30 deg-slant injection holes are distributed in the staggered array with the two kinds of hole pitches, which are five and ten hole diameters in the streamwise and lateral directions. The free stream velocity was varied as 10 and 20 m/s, respectively, and the measurement of wall surface temperature was made with the help of liquid crystal as a temperature indicator. From these experiments, basic data are given for the head loss coefficient across the FCFC plate as well as the local and averaged cooling effectiveness for each material tested. Finally the heat transfer characteristics of FCFC are discussed from the heat balance of unit hole element and a technique for higher cooling effectiveness is demonstrated.
Economics of Heavy Fuels in Gas Turbines and Combined Cycles
Authors: Tomlinson L. O. , Nh R. K.
Published: April 2015

Operating experience has established the ability of gas turbines and combined cycles to utilize heavy fuel oils for power generation economically and reliably. The technical factors related to operation of gas turbines on heavy oils are discussed and installation and operating costs are developed for each of these factors for economic evaluation. Factors influencing heavy oil use include fuel specifications and treatment to prevent corrosion of hot parts, the effects of ash deposition on turbine nozzles and buckets and on boiler heat transfer surface, turbine and boiler cleaning techniques and their use for maintaining capability, and downtime for cleaning.
Combustion of Methanol and Liquefied Butane in a Gas Turbine Combustor
Authors: Kajita S. , Kitajima J. , Kimura T.
Published: April 2015

Combustion tests with a gas turbine combustor were carried out to clarify the technical problems caused when liquefied butane was supplied and burned in the liquid phase in addition to evaluating methanol and liquefied butane as an alternative fuel. For methanol, a conventional dual-orifice type fuel injector, and for liquefied butane, the same dual-orifice type injector and two types of multi-hole injectors were tested. The results of combustion tests with both fuels were compared with those of conventional gas turbine fuels — kerosene and natural gas with respect to combustion performances and exhaust emissions. It was found that both fuels had some advantages over conventional fuels.
Gas Turbine Materials Evaluation Program Utilizing Coal Derived Gaseous Fuel
Authors: Williams M. L. , Manning G. B. , Yates C. C. , Peterson R. R.
Published: April 2015

A description of a test facility established by the University of Pittsburgh under the sponsorship of the U.S. Department of Energy for (he purpose of obtaining dynamic and static test data on the erosion-corrosion characteristics of candidate materials being considered in support of the Department of Energy’s High Temperature Turbine Technology Program. The goal of this program is to establish a gross relationship between the gas turbine materials and the coke oven gas fuel being furnished by the Jones & Laughlin Steel Corp. 24-7 gas turbine engines reconfigured to burn gaseous fuel. The engines have been furnished by the Department of Defense on a loan basis. The facility is currently operational with data being obtained on INCO-713 rotor material whichis the material currently used in the 24-7 engines. Other materials and coatings will be evaluated.
The Effect of Impeller Tip Design on the Performance of a Mixed Flow Turbocharger Compressor
Authors: Whitfield A. , Roberts D. V.
Published: April 2015

It is important that turbocharger compressors have a broad operating range between surge and choke. The surge limit is controlled by flow stability in both the compressor impeller and vaneless diffuser. Theoretical studies, and to a limited extent, experimental studies, have shown that gradients of total pressure and angular momentum between the hub and shroud surfaces at diffuser inlet, as produced by the impeller, cause separation of the flow in the vaneless diffuser. This paper presents the overall performance of a turbocharger compressor employing three mixed flow impellers with the discharge blade tip designed to reduce the enthalpy gradients at diffuser inlet. It is shown that overall stability is improved by using a mixed flow impeller with a horizontal tip cut off.
Heat Transfer Coefficients for Staggered Arrays of Short Pin Fins
Authors: VanFossen G. J.
Published: April 2015

Short pin fins are often used to increase the heat transfer to the coolant in the trailing edge of a turbine blade. Due primarily to limits of casting technology, it is not possible to manufacture pins of optimum length for heat transfer purposes in the trailing edge region. In many cases the pins are so short that they actually decrease the total heat transfer surface area compared to a plain wall. A heat transfer data base for these short pins is not available in the literature. Heat transfer coefficients on pin and endwall surfaces were measured for several staggered arrays of short pin fins. The measured Nusselt numbers when plotted versus Reynolds numbers were found to fall on a single curve for all surfaces tested. The heat transfer coefficients for the short pin fins (length to diameter ratios of 1/2 and 2) were found to be about a factor of two lower than data from the literature for longer pin arrays (length to diameter ratios of about 8).
Inverse or Design Calculations for Non-Potential Flow in Turbomachinery Blade Passages
Authors: Thompkins W. T. , Tong Siu Shing
Published: April 2015

A new inverse or design calculation procedure has been devised for non-potential flow fields and has been applied to turbomachinery blade row design. This technique uses as input quantities the surface pressure distribution and geometric constraints and may be used for two- or three-dimensional flows as well as inviscid or viscous flows. If a geometry satisfying both the constraints and the pressure distribution cannot be found, a solution satisfying the constraints and a relaxed pressure distribution is found. Calculational examples are presented for inviscid supersonic compressor cascade designs and the extension to three-dimensional flows discussed.
Advanced Coatings for Gas Turbine Materials
Authors: Stiglich J. J. , Hozl R. A. , Bhat D. G.
Published: April 2015

San Fernando Laboratories (a division of Dart Industries) has been involved in the development of advanced materials and coating systems for structural use at elevated temperatures. This paper describes these activities including development of additional protection for thermal barrier materials and the development of an extremely high performance SiC coating. Problems of utilizing these and other coatings with carbon-carbon composites are also described.
A UK View on Future Fuels
Authors: Wessell A. B.
Published: April 2015

The pressures within the U.K. to mount a large and rapid program on future fuels are minimal because of its off-shore oil fields. However, as a major exporter of aircraft engines which operate worldwide, some work has proceeded over the past five years to determine the impact of a deteriorating fuel specification. Much of this work has been aimed at the industrial uses of aircraft using diesel fuel as the alternative to kerosine. Trends have been established for emissions (gaseous and black smoke) which agree with data published by other observers. However rig data at high pressures (>20 Bars) from a tubular combustor suggest that increases in liner temperatures may not have as great an impact on combustor life as some have concluded. General comments on the production of “white smoke” at sub-idle conditions and the impact of reduced thermal stability are included.
Rotor Wake Mixing Effects Downstream of a Compressor Rotor
Authors: Ravindranath A. , Lakshminarayana B.
Published: April 2015

An experimental study of rotor wake was conducted in the trailing-edge and near-wake regions of a moderately loaded compressor rotor blade using a rotating tri-axial hot-wire probe in a rotating frame of reference. The flow fieldwas surveyed very close to the trailing-edge as well as inside the annulus- and hub-wall boundary layers. The large amount of data acquired during this program has been analyzed to discern the decay effects as well as the span wise variation of three components of velocity, three components of intensities and three components of shear stresses. The data set also include extensive information on the variation of the flow properties downstream. The other derived quantities include wake momentum thickness and deviation angles at various span wise and downstream locations. These data are presented and interpreted, with emphasis on the downstream mixing as well as endwall-wake interaction effects.
Fluid Pulsed Thermocouple Rake System for Automated High Gas Temperature Measurements
Authors: Gabriel F. K. , DeZubay E. A. , Mitchell R. W.
Published: April 2015

An integral fluid pulsed gas temperature measuring system has been evaluated in a full scale combustion test facility. This was accomplished using an available thermocouple rake which was not specifically designed for pulse operation, but was designed as an aspirating rake. This feature made it possible to use an existing design to verify a cooled/aspirating (pulsed) rake arrangement. Tests were made at various percentages of combustion temperature step changes. The objective was to provide small extrapolation errors with moderately fluctuating combustion turbine inlet temperatures while extending the useful life of thermocouple rakes by measuring to less than full operating test temperatures. This provided a temperature measuring system for operational use in development testing and also could be applied to supervisory control functions as increased reliability and compactness is achieved through the further development in data acquisition and microelectronics.
Scale Combustor Tests With Simulated Lower Heating Value Gas
Authors: McWhirter A. , Dezubay A. E.
Published: April 2015

As part of an overall program to support an application involving a medium BTU fuel gas consisting of carbon dioxide and hydrocarbons, experiments have been carried out on a scale combustor to examine the implications for design. The test program was designed to investigate the effect of mass and velocity loading, primary zone stoichiometry and fuel composition. Total gas analyses were carried out for O2, CO, CO2, NOx, and unburned hydrocarbons. The method of linear regression analysis has provided a rapid means for rationalizing data obtained from the model combustor which could then be used to predict full scale combustor performance.
Combined Power and Heat Production With Gas Turbines and Their Control Methods
Authors: Frutschi H. U.
Published: April 2015

The part load behavior of cogeneration with open cycle gas turbines and standard power control by temperature variation is poor if total fuel utilization is considered. Therefore, alternative control methods and their effect on total fuel utilization are analyzed. A simple method with a good partload behavior is proposed. The heat balances of waste heat utilization from constant speed, single shaft gas turbines are shown and discussed. Additional heat production with auxiliary burners in waste heat boilers is analyzed and a more effective solution with supplementary boilers is proposed. The combined power and heat production characteristics with compressor backflow and supplementary boilers point to the outstanding cogeneration behavior of simple open cycle gas turbines. The very good power to heat ratio and the high exhaust gas temperature of the turbine enables an efficient combination with bottoming steam cycles and compression and absorption heat pumps. This indicates the potential of fuel utilization for heating purposes.
Influence of Endwall Flow on Airfoil Suction Surface Mid-Height Boundary Layer Development in a Turbine Cascade
Authors: Sharma O. P. , Graziani R. A.
Published: April 2015

This paper presents the results of an analysis to assess the influence of cascade passage endwall flow on the airfoil suction surface mid-height boundary layer development in a turbine cascade. The effect of the endwall flow is interpreted as the generation of a cross flow and a cross flow velocity gradient in the airfoil boundary layer, which results in an extra term in the mass conservation equation. This extra term is shown to influence the boundary layer development along the mid-height of the airfoil suction surface through an increase in the boundary layer thickness and consequently an increase in the mid-height losses, and a decrease in the Reynolds shear stress, mixing length, skin friction, and Stanton number. An existing two-dimensional differential boundary layer prediction method, STAN-5, is modified to incorporate the above two effects.
Short Duration Heat Transfer Studies at High Free-Stream Temperatures
Authors: Kercher D. M. , Sheer R. E. , So R. M. C.
Published: April 2015

This paper describes short duration heat transfer measurements on a flat plate and a gas turbine nozzle airfoil at high free-stream temperatures. A shock tube generated the high temperature and pressure air flow. Thin-film heat gages recorded the surface heat flux. The flat plate was tested both in the shock tube and in a shock tunnel placed aft of the tube. Shock tunnel tests on the nozzle airfoil measured the local heat transfer distribution. The flat plate free-stream temperatures varied from 830 °R (460 K) to 3190 °R (1770 K) for a Tw/TT,g temperature ratio of 0.17 to 0.64 at Mach numbers from 0.12 to 1.34. The nozzle measurements at a Tw/TT,g of 0.35 to 0.39 generally indicate that pressure (concave) surface heat transfer coefficients are high, whereas the suction (convex) surface shows much lower heat transfer coefficients than a turbulent flat plate correlation.
Feasibility of Compressors and Expanders Utilizing Cascades of Oscillations Airfoils
Authors: Sisto F.
Published: April 2015

Linear cascades of airfoils in phased harmonic plunging and pitching oscillating are capable of absorbing energy from an airstream or alternatively adding energy thereto; they are potential compressors or expanders. Leaving aside the specific kinematic synthesis in the design of these prospective machines, the feasibility of oscillation and the predicted relationship among geometrical parameters, flow velocity, power, efficiency, pressure ratio, oscillation mode and frequency are examined.
Analysis and Test of Coolant Flow and Heat Transfer of an Advanced Full-Coverage Film-Cooled Laminated Turbine Vane
Authors: Yoshida T. , Takahara K. , Kumagai T.
Published: April 2015

A laminated and diffusion bonded turbine vane was designed and manufactured with stainless steel wafers. By the use of photo chemical etching, it was possible to make many elaborate and fine cooling passages. The description of the cooling passage construction is given in this paper. Coolant flow analysis has been done and corrected with the aid of preliminary coolant flow discharge test data without the mainstream. Cooling effectiveness analysis by cascade test has also been performed. Corrected flow analysis shows good agreement with the cascade test data. The resulting cooling effectiveness distribution shows relatively small deviation from the averaged value and it is located at the high level of 0.7 with a coolant flow rate ratio of 6 percent. The analysis and discussion are also presented in this paper.
Auto and Cross Correlation Measurements in a Turbine Cascade Using a Digital Correlator
Authors: Bryanston-Cross P. J. , Camus J. J.
Published: April 2015

A simple technique has been developed which samples the dynamic image plane information of a schlieren system using a digital correlator. Measurements have been made in the passages and in the wakes of transonic turbine blades in a linear cascade. The wind tunnel runs continuously and has independently variable Reynolds and Mach number. As expected, strongly correlated vortices were found in the wake and trailing edge region at 50 KHz. Although these are strongly coherent we show that there is only limited cross-correlation from wake to wake over a Mach no. range M = 0.5 to 1.25 and variation of Reynolds number from 3 × 105 to 106. The trailing edge fluctuation cross correlations were extended both upstream and downstream and preliminary measurements indicate that this technique can be used to obtain information on wake velocity. The vortex frequency has also been measured over the same Mach number range for two different cascades. The results have been compared with high speed schlieren photographs.
Automatic Test Rig and Control for Ceramic Turbine Component Evaluation
Authors: McLean A. F. , Trela W. , Arnon N. , Dent J. R. , Evans R. G.
Published: April 2015

This paper describes an automatic, high temperature test rig and control system for accurate and consistent evaluation of ceramic turbine Stators or other stationary flowpath components. A unique feature is an electronic, programmable control system providing automatic thermal cycling and closed loop control of key variables. The basic operating features of the computing section are briefly described showing how digital software can establish various analog control functions, especially those specific to this application. The commissioning of the test rig and control system is discussed and performance characteristics presented.
Convective Heat Transfer in a Rotating Cylindrical Cavity
Authors: Owen J. M. , Onur H. S.
Published: April 2015

In order to gain an understanding of the conditions inside air-cooled gas-turbine rotors, flow visualization, laser-doppler anemometry and heat-transfer measurements have been made in a rotating cavity with either an axial throughflow or a radial outflow of coolant. For the axial throughflow tests, a correlation has been obtained for the mean Nusselt number in terms of the cavity gap ratio, the axial Reynolds number and rotational Grashof number. For the radial outflow tests, velocity measurements are in good agreement with solutions of the linear (laminar and turbulent) Ekman layer equations, and flow visualization has revealed the destabilizing effect of buoyancy forces on the flow structure. The mean Nusselt numbers have been correlated, for the radial outflow case, over a wide range of gap ratios, coolant flow rates, rotational Reynolds numbers and Grashof numbers. As well as the three (forced convection) regimes established from previous experiments, a fourth (free convection) regime has been identified.
The Influence of Tip Clearance, Stage Loading, and Wall Roughness on Compressor Casing Boundary Layer Development
Authors: Bettner J. L. , Elrod C.
Published: April 2015

An experimental program was conducted in a highly loaded, single-stage, low-speed research compressor that featured variations in blade tip clearances, shroud wall roughness, and stage loading levels. The results showed that tip clearances and stage loading levels exerted a very strong influence on casing boundary layer growth. Shroud wall roughness not only showed some effect on casing boundary layer development, but also influenced stage stall margin. The results point out the need to understand the basic flow processes that occur if realistic mathematical models are to be developed so that casing boundary layer development and its influence on compressor stage performance can be accurately predicted.
Status Report: Advanced Heat Exchanger Technology for a CCGT Power Generation System
Authors: Wright D. E. , Tignac L. L.
Published: April 2015

Rocketdyne is under contract to DOE for the development of heat-exchanger technology that will allow coal to be burned for power generation and cogeneration applications. This effort involves both atmospheric fluidized bed and pulverized coal combustion systems. In addition, the heat-exchanger designs cover both metallic and ceramic materials for high temperature operations. This paper reports on the laboratory and small AFB test results completed to date. It also covers the design and installation of a 6 × 6 ft-atmospheric fluidized bed test facility being used to correlate and expand the knowledge gained from the initial tests. The paper concludes by showing the direction this technology is taking and outlining the steps to follow in subsequent programs.
A Fluidized Bed Combustion Heat Transfer Model Using Finite Elements
Authors: Jenkins P. E. , Richardson T. W.
Published: April 2015

This paper deals with the analysis of the axisymmetric heat transfer which occurs in a cylindrical combustion chamber using the finite element technique. The formulation of the equations used in the finite element method presented in this paper begins with the derivation of the heat conduction in three-dimensional polar coordinates. Through a series of transformations, the Poisson’s equation is numerically integrated to obtain the surface temperatures and overall heat transfer rates for the fluidized bed model. Several examples are given to demonstrate the application of the finite element principles to a thermal problem.
Aerodynamic Performance of Large Centrifugal Compressors
Authors: Kano Fumikata , Tazawa Noriyuki , Fukao Yoshiteru
Published: April 2015

The aerodynamic performance of impellers and diffusers of the large centrifugal compressor were studied. A performance design procedure based on the quasi-three-dimensional flow analysis which is combined with the boundary layer theory was developed. The conditions of the boundary layer at the impeller exit and at the diffuser vane throat were calculated, and the three-dimensional measurements were carried out. This result shows that the low momentum flow is accumulated at the corner of the shroud and the blade suction side of the impeller. These results were applied to the development of a large four-stage isothermal compressor which handles the air for an air separation apparatus. This was tested in the field and showed an isothermal efficiency of 76 percent.
Aeropropulsion Research for the U.S. Army
Authors: Singleton R. E.
Published: April 2015

A timely review of selected examples of research in aeropropulsion being sponsored by the U. S. Army covering the full spectrum of relevant topics is given. The discussion in this paper is focussed on aerodynamic components, mechanical elements and materials with emphasis on those fundamental issues which strongly influence engine reliability and life-cycle cost, particularly reduced fuel consumption. Specific research investigations on compressors, combustors, turbines, mechanical components, materials and cycle analysis are described and new desired research initiatives are elaborated. The reader can acquire a rather complete overview of Army activities related to small gas turbine engines from this paper.
The Design of an Advanced Cooled First Stage for a Full-Scale Utility Combustion Turbine
Authors: Levari G. N. , Sauer J. D. , Cohn A.
Published: April 2015

The design of an advanced cooled first stage for a full-scale utility size combustion turbine is discussed. The preliminary design work involved evaluating three candidate “skin/spar” concepts: the shell/spar, Lamilloy*/spar and hybrid configurations. A shell/spar concept at 1600°F (871°C) maximum metal temperature was selected for continued development because it ensures against transpiration hole plugging; temperature selection was based on performance and corrosion considerations. The detailed design of the shell/spar advanced cooled stage is featured in this presentation and includes heat transfer and mechanical designs, stress analyses and durability considerations, and material selection. The fabrication process and acceptance tests planned for the advanced cooling components are described along with the shop and field tests proposed for the demonstration engine.
Combustor Flame Radiation and Wall Temperatures for #2 Distillate and a Coal Derived Liquid Fuel
Authors: Kuznar R. J. , Tobery E. W. , Cohn A.
Published: April 2015

Flame radiation measurements were made in the primary zone of a film cooled gas turbine combustor, while burning #2 distillate (13 percent H) and a coal derived liquid fuel (8.7 percent H), from the SRC II process. Measurements from three circumferentially located radiometers indicate an average increase in flame heat flux of 55 percent, during combustion of the SRC II blend. Individual radiometer readings measured an increase ranging from 52 to 60 percent. Analytical predictions of the average combustor metal temperature, for the SRC II blend, cannot be explained by the increase in flame heat flux alone. If the same temperature of hot gases which mix in with film cooling air is used for both fuels then the calculated temperatures for SRC II fuel would be higher than those measured. Therefore, a lower value for hot gas temperature is required for the SRC II fuel case. This difference is attributed to the difference inflame shape between the two fuels.
High-Temperature Turbine Technology Readiness
Authors: Horner M. W. , Caruvana A.
Published: April 2015

Final component and technology verification tests have been completed for application to a 2600°F rotor inlet temperature gas turbine. These tests have proven the capability of combustor, turbine hot section, and IGCC fuel systems and controls to operate in a combined cycle plant burning a coal-derived gas fuel at elevated gas turbine inlet temperatures (2600–3000°F). This paper presents recent test results and summarizes the overall progress made during the DOE-HTTT Phase II program.