bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Station Engineering Electrical/Controls Construction Database
Authors: Thébeau Michèle A. 
Published: February 2015

This paper will discuss the structure, features and capabilities of the Union Gas Ltd. Station Engineering Electrical/Controls Construction Database.
The central feature of the application is the R:BASE database. In general, the database contains information which pertains to a transmission, measurement, regulating and/or compressor station. From the menu-driven custom application software used with R:BASE, the user can perform mass data manipulation to maintain the database, as well as create reports such as the equipment catalogue report. Finally, data can be extracted from the database to auto-generate junction box termination schedules as well as auto-generate, through a CAD software package, instrumentation loop drawings. These have the ability to show information such as panel and I/O module terminations, junction/termination box schedules, cable and conduit schedules, and device information such as alarm, shutdown and control setpoints.
Viscous Flow Field Computations for the VKI–1 Turbine Cascade Using Different Turbulence Models
Authors: Lenke L. J. , Reichert A. W. , Simon H. 
Published: February 2015

The influence of the turbulence modelling on viscous flow field calculation results has often been discussed in the past. For a meaningful comparison of different turbulence models the access to reliable measurement data is necessary. The plane VKI–1 turbine profile has been investigated experimentally in many publications. Therefore this turbine profile is chosen for transonic 2D flow field calculations using three different turbulence models. The algebraic model of Baldwin and Lomax, the Standard k–ϵ model with wall functions and a low–Reynolds number model are considered in this investigation.
The main differences between the models become apparent in the trailing edge region. The turbulence modelling influences the boundary layer thickness and the shape of the shear layers and the separation region in the wake flow. For the high Mach numbers appearing in this region, a strong influence on the flow field due to small shear layer changes has been found.
Design and Flow Field Calculations for Transonic and Supersonic Radial Inflow Turbine Guide Vanes
Authors: Reichert A. W. , Simon H. 
Published: February 2015

The design of radial inflow turbine guide vanes depends very much on the discharge conditions desired, especially if the choking mass flow is reached. Because of the choking mass flow condition and supersonic discharge Mach numbers, an inverse design procedure based on the method of characteristics is presented. Various designs which correspond to different discharge Mach numbers are shown. Viscous and inviscid flow field calculations for varying discharge conditions show the properties of the guide vanes at design and off–design conditions.
In a previous paper (Reichert and Simon 1994), an optimized design for transonic discharge conditions has been published. In the present paper, additional results concerning the optimum design are presented. For this optimum design an advantageous adjusting mechanism for a variable geometry guide vane has been developed. The effect of guide vane adjustment on the discharge conditions has been investigated using viscous flow field calculations.
Development of Air-Cooled Ceramic Nozzles for a Power Generating Gas Turbine
Authors: Tsuchiya Toshiaki , Furuse Yutaka , Yoshino Shin , Chikami Rintaro , Tsukagoshi Keizo , Mori Masahiko 
Published: February 2015

The development of air-cooled ceramic nozzle vanes for a power generating gas turbine has been reported. To make up the limited temperature resistance of present ceramic materials, the utilization of a small amount of cooling air has been studied for the first stage nozzle vanes of a 1500°C class gas turbine.
A series of cascade tests were carried out for the designed air-cooled Si3N4 nozzle vanes under 6 ata and 1500°C conditions. It was confirmed that the maximum ceramic temperature can be maintained below 1300°C by a small amount of cooling air. In spite of the increased thermal stresses by local cooling, all Si3N4 nozzle vanes survived in the cascade tests including both steady state and transients of emergency shutdown and the possibility of air cooled ceramic nozzle was demonstrated for a 1500°C class gas turbine application.
Two-Phase Air/Oil Flow in Aero Engine Bearing Chambers: Characterization of Oil Film Flows
Authors: Glahn A. , Wittig S. 
Published: February 2015

For the design of secondary air and lubrication oil systems a sufficient knowledge on two-phase flow and heat transfer phenomena under bearing chamber flow conditions is required. The characterization of oil film flows at the bearing chamber walls is one of the major tasks for a better understanding of these processes and, therefore, a necessity for improvements of the efficiency of aero engines. The present paper gives a contribution to this subject.
Utilizing a fibre-optic LDV-setup, measurements of oil film velocity profiles have been performed in our high speed bearing chamber rig simulating real engine conditions. All data have been compared with different theoretical approaches which have been derived from a force balance at a liquid film element, including geometrical conditions and temperature dependent fluid properties, and by approaches for the eddy viscosity available in the literature.
Predicted Performance of a Thrust-Enhanced SR-71 Aircraft With an External Payload
Authors: Conners Timothy R. 
Published: February 2015

NASA Dryden Flight Research Center has completed a preliminary performance analysis of the SR-71 aircraft for use as a launch platform for high-speed research vehicles and for carrying captive experimental packages to high altitude and Mach number conditions. Externally mounted research platforms can significantly increase drag, limiting test time and, in extreme cases, prohibiting penetration through the high-drag, transonic flight regime.
To provide supplemental SR-71 acceleration, methods have been developed that could increase the thrust of the J58 turbojet engines. These methods include temperature and speed increases and augmentor nitrous oxide injection. The thrust-enhanced engines would allow the SR-71 aircraft to carry higher drag research platforms than it could without enhancement.
This paper presents predicted SR-71 performance with and without enhanced engines. A modified climb-dive technique is shown to reduce fuel consumption when flying through the transonic flight regime with a large external pay load. Estimates are included of the maximum platform drag profiles with which the aircraft could still complete a high-speed research mission. In this case, enhancement was found to increase the SR-71 payload drag capability by 25 percent. The thrust enhancement techniques and performance prediction methodology are described.
Emission Monitoring and Testing of Combustion Processes
Authors: Wagner George H. 
Published: February 2015

An outline of the federal regulations which require toting and continuous monitoring of combustion process emissions is presented. A discussion of the NOx RACT regulations and the differences between selected state agencies is presented. A brief review of the components of the proposed enhanced monitoring rule is provided.
The technology and types of continuous emission monitors (CEM) currently available for criteria and hazardous air pollutants are described. The new CEM technologies being developed for criteria and hazardous air pollutants are summarized. The factors to be considered in purchasing, installing, certifying and operating a CEM system are outlined.
The approved EPA test methods, procedures for new test method development and the new EPA stationary source and analyses database are reviewed. The use of continues monitors to develop individual combustion curves for optimization of reduced emissions is summarized. The Office of Air Quality Planning and Standard (QAQPS) network of databases is introduced.
Design of Inlet Conditions for High Pressure NOx Measurements in Lean Premixed Combustors
Authors: McDonald Jon P. , Mellor Arthur M. 
Published: February 2015

Semi–empirical characteristic time models (CTMs) for NOx emissions index (EI) and lean blowoff are used in the design of an inlet condition matrix for measurement of NOxEI from a lean premixed combustor. Such models relate either NOxEI or the weak extinction limit to times representing relevant physical and chemical processes in the combustor. Lean premixed (LP) natural gas/air combustion is considered for the following conditions: inlet temperature, 300–800 K; combustor pressure, 1–30 atm; and equivalence ratio, 0.5–0.7.
The NOx model is used to determine combinations of inlet conditions corresponding to greatest NOx sensitivity. A dependence of NOx emissions on pressure is included in the model. Emissions of oxides of nitrogen are found to he most sensitive to variations in inlet temperature and combustor pressure, in the 560–800 K and 20–30 atm ranges, respectively, while sensitivity to variations in equivalence ratio is substantial over the entire range considered. Thus it is found that operating conditions for high thermal efficiency in LP turbine combustors conflict with the goal of lowering NOx emissions, a result consistent with thermal NOx from conventional, diffusion flame combustors.
A lean blowoff model is used to estimate the lowest equivalence ratio at which a flame can he held, as well as to determine whether a flame can be stabilised at the operating conditions suggested by the NOx sensitivity analysis. The results suggest a nominal lower limit on equivalence ratio of 0.4, and that a flame can be held for most of the combinations of inlet conditions suggested by the NOx sensitivity analysis. Autoignition of the fuel/air mixture is also considered in relation to the location and/or design of the premixing system.
The current NOx CTM is applied to LP natural gas fired data from the literature. A model modification, thought to better represent the fluid mechanics relevant to LP NOx formation, is applied, and its implications discussed.
Digital Control of the WR21 Intercooled Recuperated Gas Turbine
Authors: Carlson R. J. , Olson R. E. 
Published: February 2015

The on-going development of a full authority digital engine control (FADEC) system for the US Navy’s Intercooled Recuperated (ICR) gas turbine requires a high level of system coordination to achieve the primary benefits of reduced specific fuel consumption and improved specific output power relative to a simple cycle engine. This paper describes the system evolution and the hardware and associated control algorithms implemented in the Advanced Development prototype ICR control system design.
The ICR control system is required to coordinate the actions of 58 actuator channels using data taken from 141 sensors. Primary control of the engine output power is provided by regulation of the fuel metering valve. Thermal management of the intercooler, recuperator, and variable area power turbine nozzle results in maximum cycle efficiency within safe operating limits.
The new electronic engine controller (EEC) is based on an open architecture Futurebus+ backplane and is fully redundant in all operationally critical control functions. The EEC also features an integrated operating panel and video display for local operation and maintenance of the control system. The graphical display and function keys provide access to control functions as well as assist maintenance activities with built-in test diagnostics to trouble shoot failed circuitry.
Experimental and Numerical Investigations of Aerodynamic Aspects of Hot Gas Ingestion in Rotor-Stator Systems With Superimposed Cooling Mass Flow
Authors: Bohn Dieter , Johann Erik , Krüger Uwe 
Published: February 2015

Modern “High Temperature Gas Turbines” need very complex cooling configurations. Not only the turbine vanes and blades, but also the turbine discs, are cooled by air flow extracted from the compressor. Therefore, rotor-stator systems with a superimposed cooling mass flow are found in many constructions of gas turbines. The hot gas ingress into the wheelspace between stator and-rotor, taking place under special conditions, is one of the major problems in these systems.
An experimental set-up has been built to get a better knowledge of the aerodynamics of such configurations. The ingress of hot gas into the wheelspace with different sealing configurations has been considered by the measurements of surface pressure and velocities (using the LDA-measurement technique) in the shrouded rotor-stator-system. A variable mainstream flow (Ma-number up to 0.7, Re-number up to 2·106) — with and without nozzle guide vanes — has been realized, to obtain flow situations approximating those in real gas turbines.
Parallel to the experiments, the flow structure has been calculated numerically using a modern multiblock finite-volume-scheme with non-orthogonal body-fitted grids. The influence of the mainstream flow has also been taken into account. Two different versions of the k-ε-turbulence model have been used to describe the turbulent effects of the flow.
Important features of the experimental results are as follows: hot gas ingress can not only occur on the stator but also on the rotor side of the wheelspace depending on the conditions between the cooling gas and the mainstream flow. In real systems with pressure and velocity gradients in the circumferential direction, hot gas ingestion can not be completely prevented. It was only in the 2-D-axisymmetric case, without guide nozzles in the mainstream, that hot gas ingress could be suppressed completely. The numerical data has been compared to the solution obtained by similitude theory as well as to the measurements. It was found that the data correspond reasonably well. The numerical results confirm the conclusions drawn by experiment about the physical mechanism of hot gas ingress into the wheelspace.
Advanced User-Friendly Gas Turbine Performance Calculations on a Personal Computer
Authors: Kurzke Joachim 
Published: February 2015

Personal Computers are nowadays very powerful. They allow us to do complete gasturbine performance calculations both for the engine design point and the partload behavior. A typical helicopter engine serves as an example for a cycle study. The simple variation of compressor pressure ratio and turbine inlet temperature, however, does not yield a realistic result. Only after including the effects of variable amounts of cooling air needed for constant metal temperature and turbine efficiency as a function of aerodynamic loading one does get results that are in line with the cycle of real engines.
Off-design performance calculations need no longer use crude simplifications for reasonable calculation times. Real component maps can be used while the matching of the cycle is done by iterative methods. Transient simulations on a 486DX machine are only a matter of a few minutes. Even the effects of inlet distortion (pressure or temperature) can be dealt with by using the parallel compressor model.
The key to userfriendliness is, to hide everything from the user that he does not need to know at the very moment. The things he needs to know, however, must be presented in clear and easily understandable expressions. Results must be shown in graphics whenever it makes sense. This is the only way to recognize quickly problem areas or to convince people, that the selected design is optimal.
Characteristics Charts for Preliminary Design and Selection of a Gas Turbine Cogeneration Plant
Authors: Sarabchi K. , Polley G. T. 
Published: February 2015

The important and well-established performance criteria for assessment of a gas turbine cogeneration plant (GTCP) were examined. It was found that expressions could be derived for these criteria in terms of two key parameters: work efficiency and boiler efficiency. Three characteristics charts were then constructed. These covered gas turbine analysis, boiler analysis and GTCP performance analysis respectively. It is then demonstrated how these charts may be used as an effective tool for both performance prediction and preliminary design analysis.
Thermodynamic design of a GTCP as an integrated system is also investigated and discussed.
Field Experience Versus Theory in Turbine Engine Deterioration
Authors: Pettigrew James L. 
Published: February 2015

This paper describes observations and analysis of data recorded on operating helicopter engines using advanced technology data recording systems. The US Army began the test on TS3 engines in 1986 and expanded it to their T55, T63, T700, and T703 helicopter engines in 1990. These engines have a gas generator with a free turbine for power production. A portable instrumentation system is used to do inflight helicopter engine tests and electronically record performance information.
A PC based data analysis system uses artificial intelligence to change the data into diagnostic information for the test engine’s capability to perform the missions. The data output presents this information in an easily understandable format that allows the decision maker to see differences in the condition of individual engines and rank them on their relative capability. The resulting data base clearly shows each engine’s on-condition status. Valid knowledge of each engine’s condition is very valuable as the basis for decisions that direct the limited resources to the least capable engines.
Rejection criteria for installed engine deterioration does not fully agree with observed operational behavior. Observations that are different are: (1) a deteriorated engine’s gas generator slows down when running at rated power yet no minimum speed limit exists and (2) a deteriorated engine operates at a lower SFC than a newly overhauled one yet no minimum limit exists, instead, both conditions are considered indications of better engines.
NOx Emission Characteristics of a Catalytic Combustor Under High-Temperature Conditions
Authors: Valk Martin , Vortmeyer Nicolas , Kappler Günter 
Published: February 2015

A catalytic combustor concept with short catalyst segments and a thermal reactor is investigated with regard to NOx production of this concept under high-temperature conditions. The maximum combustor exit temperature was more than 1800 K with catalyst temperatures below 1300 K. For combustion of iso-octane, NOx emissions of 4 ppm (dry, 15% O2) at a flame temperature of 1800 K were measured. No significant influence of catalyst length, reference velocity and overall residence time on NOx emissions was observed.
Additionally, the test combustor was fuelled with commercial diesel and kerosene (Jet-A). In this case, NOx emissions were noticeable higher due to fuel-bound nitrogen. The emissions measured were for diesel, 12 ppm, and for kerosene, 7 ppm, (each dry, 15% O2), again at a flame temperature of 1800 K. To evaluate the conversion ratio of fuel-bound nitrogen to NOx iso-octane was doped with various amounts of ammonia and metyhlamine. The conversion rates were 70 to 90%, with a slight tendency to lower values (50%) for nitrogen mass fractions above 0.1%.
Considering the NOx emission level of actual premix burners, the lower emission value of the presented catalytic combustor results from a perfect premixed plug-flow combustion system incorporating a catalyst herein and not from a specific advantage of the principle of catalytic combustion itself. Again similar to a premix-combustor are the NOx emission characteristics in the case of lean combustion of nitrogen bound fuels, which yield very high conversion rates.
Stator Exit Flow Fields in the Multistage Environment of an Axial Compressor
Authors: Jung M. , Eikelmann J. 
Published: February 2015

Detailed measurements have been taken at the exit of the four stages of an axial compressor of industrial design for two operating points. Pneumatic probes and fast response pressure transducers have been used. Special attention is paid to the endwall flow near hub and casing and the stage-by-stage development of this region of high loss.
The steady state investigations show the leakage flow to be the dominant feature of the endwall region near the hub. This is also apparent near the casing for the unshrouded and adjustable stator blades. At the hub this flow phenomenon intensifies axially from stage-to-stage and with increased aerodynamic loading.
Variations in geometry of the radial clearance at the casing have been investigated to understand the structure and effects of the leakage flow.
Unsteady state flow measurements confirm the steady state results. Further, the endwall flow and especially the leakage vortex are detected as regions of high periodic fluctuations.
Gas Turbine Performance: New Application and Test Correction Curves
Authors: Cloyd Scott T. , Harris Arthur J. 
Published: February 2015

The gas turbine industry has adopted the practice of rating engine performance at ISO standard conditions; 15 degrees C, 1.033 ata, 100% methane fuel, and no inlet or exhaust system pressure losses with power output referenced to the generator terminals. (ISO, 1989) While these standards are useful in putting original equipment manufacturers’ (OEM’s) ratings on an equivalent basis it is not likely that an engine would be installed or tested under these types of conditions. To account for variations in engine operating conditions equipment manufacturers’ have utilized performance correction curves to show the influence of changing one operating parameter while holding all others constant.
The purpose of this paper is to review the correction curves that are used for initial project application studies, and the variations to the curves that occur when a unit is put into service as a result of the methods used to control engine operation. Sample corrections curves and a brief explanation of the correction curves are presented to illustrate the variations in the curves. The paper also presents a new method for illustrating the influence of fuel heating value and composition on engine performance for natural gas and oil fuel.
All data presented is for a single shaft, constant speed gas turbine. Two shaft or three shaft gas turbines will not have these correction curves.
A Method to Reduce the Rejection Rate for Low Performance at the Acceptance Test of PWC PT6T-6 Overhauled Power Sections
Authors: Colantuoni S. , Mainiero G. , Esposito A. 
Published: February 2015

Alfa Romeo Avio is involved in the overhaul process of the Pratt & Whitney of Canada PT6T-6 for the helicopter fleet of Italian Army and civil services.
The overhauled power sections suffered from a high rejection rate (about 40%) for low performance at the acceptance test. Alfa Romeo Avio R&D investigated the causes and developed a method for the reduction of rejection rate.
A first contribution to the decision support method for the selection of the optimal engine configuration can be obtained from engine thermodynamic cycle simulation, which gives indications on the behavior of the average overhauled power section.
In this paper the authors describe also a statistical model based on a cause/effect correlation between power section assembly variables and performance parameters.
A simulation procedure, based on the statistical model, estimates the influence of the configuration assembly data on the power section performance parameters.
A careful application of both statistical and thermodynamic models gives predictions on the optimum matching of turbine nozzle size to reach the target performance at the engine acceptance test.
The method has been tested on the field during last two years and a reduction in the rejection rate at the acceptance test to 18% has been obtained.