bluuebunny/crossref_metadata_2025 huggingface dataset:
An Experimental Study of the Aerodynamics and Performance of a Vertical Axis Wind Turbine in a Confined and Unconfined Environment
Authors: Dossena Vincenzo , Persico Giacomo , Paradiso Berardo , Battisti Lorenzo , Dell'Anna Sergio , Brighenti Alessandra , Benini Enrico
Published: April 2015

This paper presents the results of a wide experimental study on an H-type vertical axis wind turbine (VAWT) carried out at the Politecnico di Milano. The experiments were carried out in a large-scale wind tunnel, where wind turbines for microgeneration can be tested in real-scale conditions. Integral torque and thrust measurements were performed, as well as detailed aerodynamic measurements to characterize the flow field generated by the turbine downstream of the rotor. The machine was tested in both a confined (closed chamber) and unconfined (open chamber) environment, to highlight the effect of wind tunnel blockage on the aerodynamics and performance of the VAWT under investigation. The experimental results, compared with the blockage correlations presently available, suggest that specific correction models should be developed for VAWTs. The experimental thrust and power curves of the turbine, derived from integral measurements, exhibit the expected trends with a peak power coefficient of about 0.28 at tip-speed ratio equal to 2.5. Flow measurements, performed in three conditions for tip speed ratio equal to 1.5, 2.5, and 3.5, show the fully three-dimensional character of the wake, especially in the tip region where a nonsymmetrical wake and tip vortex are found. The unsteady evolution of the velocity and turbulence fields further highlights the effect of aerodynamic loading on the wake unsteadiness, showing the time-dependent nature of the tip vortex and the onset of dynamic stall for tip speed ratio lower than 2.
Hierarchical Superhydrophobic Copper for Sustained Dropwise Condensation
Authors: Chen Xuemei , Weibel Justin A.
Published: April 2015

Engineering surfaces that sustain continuous dropwise condensation, and are composed of materials commonly employed in heat transfer applications, are of great interest for scaled-up industrial systems. We fabricate hierarchical micro/nano-structured superhydrophobic surfaces on copper substrates. Condensate droplet growth dynamics on the as-fabricated samples were investigated using an environmental scanning electron microscope (ESEM; FEI Quanta 3D, ~6 torr, ~3 °C stage). Time-lapse ESEM images show that the condensate droplets preferentially nucleate at the bases of the hill-shaped microstructures (40 s). The droplets at the microstructure bases coalesce; merged droplets rise and appear to be suspended atop adjacent microstructures (180-220 s). These droplets, when triggered by coalescence, can gain sufficient kinetic energy by a reduction in droplet surface area/energy to spontaneously depart from the substrate. This droplet motion sweeps additional droplets in the trajectory and exposes fresh space for formation of new droplets (220-250 s). These droplet growth and departure dynamics are facilitated by the combination of microscale and nanoscale roughness features on the surface, and the behavior provides important insight into surface design requirements for sustaining dropwise condensation in thermal management applications.
Spatial Control of Condensate Droplets on Superhydrophobic Surfaces
Authors: Ölçeroğlu Emre
Published: April 2015

Super-bi-philic surfaces have been fabricated and characterized using environmental scanning electron microscopy (ESEM) to demonstrate spatial control of microscale droplets during condensation. The surfaces are composed of biotemplated nickel nanostructures based on the self assembly and metalization of the Tobacco mosaic virus. They are then functionalized using vapor-phase deposition of trichlorosilane, and lithographically patterned to create engineered nucleation sites. The resulting surfaces are primarily superhydrophobic (θ ≈ 170°) with arrays of superhydrophilic islands (θ ≈ 0°) with diameters of 3 μm and center-to-center pitches varying from 10 – 50 μm. During condensation the superhydrophilic islands promote nucleation resulting in spatial control of the condensate, which forms into ordered rectangular arrays (a,b). This spatial control has been shown to produce efficient jumping-mode condensation for pitches greater than 15 μm, as well as promote multi-droplet events (c). Additionally, super-bi-philic surfaces have been shown to delay the transition to a flooded state at high supersaturations, as compared to superhydrophobic designs.
Filmwise-to-Dropwise Condensation Transition Enabled by Patterned High Wetting Contrast
Authors: Hou Youmin , Yu Miao , Chen Xuemei , Wang Zuankai
Published: April 2015

Recent advances in condensing surfaces with hybrid architectures of superhydrophobic/hydrophilic patterns allow us to decrease the nucleation energy barrier and spatially control the water condensation. However, the condensed water is susceptible to the large pinning force of the hydrophilic area, leading to an ultimate flooding. Here, we demonstrate a hierarchical nanostructured surface with patterned high wetting contrast to achieve a natural transition from filmwise-to-dropwise condensation, which reconciles the existing problems. The energy-dispersive X-ray spectroscopy (EDX) indicates that the fluorinated hydrophobic coating conformably covers the nanostructures except for the tops of micropillars, which are covered by hydrophilic silicon dioxide (FIG 1), resulting in an extreme wetting contrast. Condensation on the hybrid surface was observed in the environmental scanning electron microscope (ESEM) and ambient conditions with controlled humidity. Water preferentially nucleates on the top of micropillars and exhibits a rapid droplet growth (FIG 2). The enhancement is attributed to the filmwise-to-dropwise transition induced by the unique architectures and wetting features of the hybrid surface (FIG 3). The water embryos initially nucleate on the hydrophilic tops and quickly grow to a liquid film covering the whole top area. Since the superhydrophobic surrounding confines the spreading of condensed water, the localized liquid film gradually transits to an isolated spherical droplet as it grows. Remarkably, the condensate morphology transition activates an unusual droplet self-propelling despite the presence of abundant hydrophilic patches. It is important to note that such coalescence-induced jumping is dependent on the size of hydrophilic patches, that is, for larger hydrophilic patches, the energy released by coalescence may not overcome the increased droplet pinning, resulting in an immobile coalescence (FIG 4). The droplet departure ensures the recurrence of filmwise-to-dropwise transition, thus prevents the water accumulation in continuous condensation. These visualizations reveal the undiscovered impact of heterogeneous wettability and architectures on the morphology transition of the condensed water, and provide important insights into the surface design and optimization for enhanced condensation.
Interval Fractile Levels for Stationary Stochastic Response of Linear Structures With Uncertainties
Authors: Muscolino Giuseppe , Santoro Roberta , Sofi Alba
Published: April 2015

In the framework of stochastic analysis, the extreme response value of a structural system is completely described by its CDF. However, the CDF does not represent a direct design provision. A more meaningful parameter is the response level which has a specified probability, p, of not being exceeded during a specified time interval. This quantity, which is basically the inverse of the CDF, is referred to as a fractile of order p of the structural response. This study presents an analytical procedure for evaluating the lower bound and upper bound of the fractile of order p of the response of linear structures, with uncertain stiffness properties modeled as interval variables subjected to stationary stochastic excitations. The accuracy of the proposed approach is demonstrated by numerical results concerning a wind-excited truss structure with uncertain Young’s moduli.
Interval Limit Analysis Within a Scaled Boundary Element Framework
Authors: Tangaramvong S. , Tin-Loi F. , Song C. M. , Gao W.
Published: April 2015

The paper proposes a novel approach for the interval limit analysis of rigid-perfectly plastic structures with (nonprobabilistic) uncertain but bounded forces and yield capacities that vary within given continuous ranges. The discrete model is constructed within a polygon-scaled boundary finite element framework, which advantageously provides coarse mesh accuracy even in the presence of stress singularities and complex geometry. The interval analysis proposed is based on a so-called convex model for the direct determination of both maximum and minimum collapse load limits of the structures involved. The formulation for this interval limit analysis takes the form of a pair of optimization problems, known as linear programs with interval coefficients (LPICs). This paper proposes a robust and efficient reformulation of the original LPICs into standard nonlinear programming (NLP) problems with bounded constraints that can be solved using any NLP code. The proposed NLP approach can capture, within a single step, the maximum collapse load limit in one case and the minimum collapse load limit in the other, and thus eliminates the need for any combinatorial search schemes.
Effect of Induced Vorticity in the Vaneless Diffuser on Performance of a Centrifugal Compressor
Authors: Ellis G. O.
Published: April 2015

The following equation represents the vorticity induced in the flow of the diffuser by a gradient in total pressure parallel to the axis of the compressor:

Ω ¯ − Ω ¯ 2 = 2 V 2 g p ( dp t dz ) 2 ( r r 2 − 1 ) [ i ¯ tan α 2 r / r 2 ( r r 2 + 1 ) + j ¯ ]

The ith component is the component of vorticity which is tangent to the flow direction while the jth component is that which is normal to the flow direction. The velocity and vorticity vectors are shown schematically in Fig. 1.
Generalized Multistage Compressor Characteristics
Authors: Mellor G. L.
Published: April 2015

Presented below is a method of calculating the off design performance of multistage axial compressor characteristics that differs in concept from previous methods. A set of resulting calculations has certain general properties, namely, that it is independent of absolute stage work and flow coefficients, number of stages, and annulus geometry. Each set depends only on a stage characteristic “shape” which is normalized so that the work coefficient is unity when the flow coefficient is unity. The principle restrictive assumption that has been made is that the effect of Mach number on the density is negligible.
Some Aspects of Stall Flutter and Compressor Blade Vibration
Authors: Parry J. Frank W.
Published: April 2015

For some ten years or more the causes and effects of stalling in relation to compressor blade vibration have been subjects of wide study. Many of these studies are so esoteric as to be of a very limited value to the practical engineer. This paper is intended to be a broad summary of the field so that the practical engineer can appreciate the mechanism of stall vibration and, consequently, what steps must be taken to ensure that vibration will not be so serious as to cause failure.
Instability and Surge in Dual Entry Centrifugal Compressors
Authors: Dussourd Jules L. , Putman William G.
Published: April 2015

While the operating characteristics of a compressor with a dual-entry impeller are similar to those of the more conventional single-entry machine, its stall behavior can have peculiarities of its own. These arise from the fact that the two impeller halves operate in parallel; each has inlet conditions that may occasionally be imperfectly matched. These conditions can result in instability. The necessity to eliminate these difficulties has stimulated considerable work at AiResearch Manufacturing Company of Arizona. As a result, the mechanism of the phenomenon has become well understood and brought well under control. The more fundamental aspects of this research are described herein.
Use of Experimentally Determined Acoustic Impedance in Analysis of Propulsion System Stability
Authors: Dailey C. L. , Brown A. C.
Published: April 2015

As indicated in Fig. 1, the concept of acoustic impedance has been used for many years in a variety of engineering problems including development of loud speakers and public address systems. It is shown (Fig. 2) that this concept can be borrowed from acoustics, generalized to include the effect of flow rate and real fluid effects such as boundary layers and shock boundary layer interactions, and applied as in Fig. 3 in the rational analysis of propulsion system transient properties.
Parallel Operation of Turbo-Compressors in a Common System
Authors: Furgerson W. T.
Published: April 2015

Nuclear reactors which are designed for power production have their heat removed by some cooling fluid which may be a liquid or a gas. Since the apparent success of the British power reactors there has been a growth of interest in gas-cooled reactors in this country.
Experiences With Gas Turbines in French Power Stations
Authors: Chambadal P.
Published: April 2015

Several gas turbines are in operation in power stations of the author’s company. Most of them were designed for production of peak-load energy and were rated at 6000-kw power output. The paper describes some of these plants and presents the methods chosen for the solution of the problems of burning heavy fuel oils and of remote control both for usual gas turbines and for free-piston gasifiers.
The Behavior of Gas Turbine Combustion Chambers While Burning Different Fuels
Authors: Kind C.
Published: April 2015

In order to gain full benefit from the versatility of the gas turbine it is desirable for combustion chambers to be designed which can burn widely different fuels without modification. Large single combustion chambers with vortex mixing appear to be very suitable. A primary condition for this is that the input of fuel should be appropriately adapted to the air-flow conditions on which the design is based.
A Fluid Mechanics Approach to the Labyrinth Seal Leakage Problem
Authors: Vermes Géza
Published: April 2015

The paper describes investigations of labyrinth seals carried out recently; derives new theoretical and semi-theoretical formulas for computation of the leakage which agree within 5 per cent with the tests for three different types of seals; off-design performance of the seals is treated theoretically and experimentally.
Operational Experience With a 15-MW Gas Turbine Generator in an Iron and Steel Works
Authors: Konig F. K.
Published: April 2015

The author states the basic philosophy for the installation of gas turbines burning blast-furnace gas in the power-generating systems of an iron and steel works. A description is given of the two gas-turbine generators at the Huttenwerk Rheinhausen, A.G. and their operating experience.
Comparison of Operating Characteristics of a Two-Shaft Gas Turbine With a Single-Shaft Gas Turbine for Gas Line Pumping
Authors: McDonough M. J.
Published: April 2015

Gas turbines are playing an important role in the ever-expanding gas-transportation industry. Coupled to a centrifugal compressor the gas turbine provides a low-cost, flexible prime mover for gas transmission. The two types of gas turbines most commonly used in this field are the single-shaft unit and the two-shaft unit. This paper describes and compares the operating characteristics of each unit along a typical centrifugal-compressor loading line for constant station discharge pressure. Horsepower-speed relationships and specific fuel consumption are considered in this comparison.
A Rapid Starting Automatic Gas-Turbine Generating Plant for Peak-Load Duty
Authors: Markham B. G.
Published: April 2015

This paper considers economics of peaking plants, importance of low capital and standby charges, rapid starting and full-load without warming up, and description of a 3-megawatt plant based on aircraft type of gas turbine. Automatic controls and safety devices, installation, silencing and problems of compressor fouling are also treated.
Considerations for Gas Turbines and Their Initial Operating Experiences at El Convento
Authors: Pfersdorff O. H.
Published: April 2015

When original negotiations are made for the presentation of a report regarding “initial operating data” or “operating results,” it is hoped that all factors will contribute toward useful information to enlighten and assist others in the same operating category. Oftentimes this is not completely accomplished in the alloted time. This paper is presented to set forth the initial operating experiences and results of two highly controlled gas-turbine units for power generation. The individual turbine arrangement, fuel systems, control systems, start-up and operating problems and a comparison of test and design data are stated. The future outlook for gas turbines in the Electricidad de Caracas system is discussed.
Report on 9000 Hr Operation of Marine Propulsion Gas Turbine in the John Sergeant
Authors: McLean H. D. , Tangerini C. C. , van Cott W. H.
Published: April 2015

The purpose of this paper is to continue the dissemination of operating and performance information, and evaluation of the gas turbine in the converted Liberty ship, John Sergeant. A detailed report is made on the inspection of gas-turbine parts, and the favorable condition shown. Design improvement suggestions for a new ship are evaluated and recommendations made for future marine applications.
Gas-Steam Power Generation
Authors: Martinuzzi P. F.
Published: April 2015

The combination of a gas turbine with a steam turbine driven by steam produced in a generator heated by the gas-turbine exhaust is studied. The field of application of such a gas-steam power plant is examined, as well as the best operational characteristics of the combination. The special features of closed-cycle gas turbines, particularly of the type used in conjunction with gas-cooled, high-temperature nuclear reactors, are shown to give considerable advantages when combined with a steam turbine.
Smoke Reduction in Residual-Fuel-Burning Gas-Turbine Combustion System
Authors: Schiefer R. B. , Gatzemeyer J. B. , Dibelius N. R.
Published: April 2015

As a result of the requirement that a gas turbine-electric locomotive operate in areas where legislation prohibits operation if the smoke in the exhaust gases exceeds a specified amount, a program was undertaken to develop a combustion system which would meet the requirements without compromising the other performance criteria. This paper describes the physical and chemical nature of smoke, the objective measurement of smoke, the effect of operating variables on smoking tendency, and finally the considerations which led to a combustion-chamber design which met the requirements as evidenced by the engine test results.
The Correlation of Turbocompressor Performance With Various Gases
Authors: Macaluso C. A.
Published: April 2015

With the performance characteristics of a turbocompressor based on one gas, it is possible to predict the approximate performance with other gases. The need for performance correlation and the advantages and limitations of the method presented are discussed from a test and application standpoint. Parameters are derived and given on charts, with a discussion of the significant factors and effects. Experimental data are correlated, demonstrating the validity and simplicity of the method. It is proposed that similar parameters and charts be incorporated into the Power Test Codes.
Description and Operating Experience of Three Regenerative-Cycle Gas Turbines Installed in an Argentine Portland Cement Plant
Authors: Thomas Rolando
Published: April 2015

The author reviews the performance data of three gas turbine units installed in his company’s two Portland cement plants. A brief backgrround of the plants’ earlier power sources is given, including the reasons for conversion to gas turbine power. The considerable economic advantages of the changeover to gas turbine are stressed and the regenerator investment recovery is outlined. Figures show a detailed layout of each plant.
A Quantitative Method of Screening Working Fluids for Rankine-Cycle Power Plants
Authors: Luchter Stephen
Published: April 2015

A method has been developed to relate the power-level range over which a particular Rankine-cycle working fluid is applicable as a function of rpm and turbine diameter. These results can be used in screening candidate working fluids. Typical results are presented in graphical form. They show that a fluid well-suited for one power level is not necessarily well-suited for some other power level. The analysis and typical results are applicable to single-stage turbines; however, the method can be extended to multistage designs.
Status of the Army Closed-Brayton-Cycle Gas Turbine Program
Authors: Bailey John A. , Jordan Franklin D. , Kinney Carey A.
Published: April 2015

A very brief history of the Army closed-Brayton-cycle gas turbine program is presented as background for discussion of the status and recent test results at the Advanced Power Conversion Experimental Facility at Fort Belvoir. The APCEF program is intended to emphasize component development in contrast to system development at the Advanced Power Conversion Skid Experiment (APCSE) at San Ramon, Calif. The APCEF is described along with the components being tested, experimental test results are discussed and analyzed, and a preliminary evaluation is presented.
A Rapid Approximate Method of Determining Axial-Flow Turbine Disk and Blade Temperatures
Authors: Simpson F. M.
Published: April 2015

A method of determining the temperature profile of a single-stage axial-flow turbine disk with uncooled blades is presented. The blade temperature is also estimated. Information required for the solution is: the gas properties and velocity entering the rotor, the blade and disk geometry, the blade fastening geometry, and the disk-to-shaft attachment geometry. Impingement disk cooling may be used. The temperature of the shaft at a point near the journal bearing mutt be assumed, but it is shown that this assumption is not critical. A stepwise numerical solution, suitable for either hand calculation or computer programming, is employed. The method may be extended to multi-stage turbines. A typical example is given and the effect of changing the radius of injection of the disk cooling air is shown.
An Examination of the Propulsion System for the Compound Helicopter
Authors: Veno Lester B.
Published: April 2015

The various design parameters which affect the performance versus speed of the compound helicopter are studied, such as disk loading, solidity, and tip speed schedule. Additional variables which are part of the compound design, such as propeller diameter, wing lift, and equivalent drag, are similarly studied. The interrelationship of each parameter is shown in terms of the total lift/propulsive power required. The study further presumes a fixed mission requirement against which each parameter is evaluated and optimized based on proper sizing and fuel usage. The study includes the direct effect of engine power/weight ratio and SFC. The paper lays a foundation for future performance analyses of this hybrid vehicle.
Development of Cartridges for Aircraft Engine Cartridge Starters
Authors: Hamrick Joseph T.
Published: April 2015

The paper discusses the problems encountered in providing a high-pressure hot-gas source to the turbine of an aircraft engine starter, the methods of solving these problems, and the design procedures followed in arriving at a solid-propellant cartridge which functioned in all the environments encountered in both storage and operation. Development techniques and results of experimental investigations are presented.
Heat Recovery for Gas Turbine an Advanced Design
Authors: Clay P. E.
Published: April 2015

This paper describes the design of a new boiler incorporating advanced features in gas turbine heat recovery. The basic requirements such as size, adaptability, and cost are listed and design parameters covering these requirements are given. Illustrations of the heat-transfer surface and boiler module are accompanied by typical curves showing heat recovery and pressure loss. The author summarizes with an outline of the advantages of this new boiler design.
Pressure Oscillations in a Combustor With Dual-Orifice Fuel Injection
Authors: Hudson Rodney H.
Published: April 2015

This paper presents a discussion of the investigation of a gas turbine engine to eliminate pressure oscillations which occurred in the combustor. The basic engine configuration and pertinent aspects of the combustor are described. The pressure oscillations were related to variations in the secondary fuel flow rate through the dual-orifice nozzles. The variations in fuel flow rate caused a fluctuation in nozzle spray characteristics which effected combustion efficiency.
Gas Turbine Propulsion for High-Speed Railcars
Authors: Garner P. B. , Hull W. L.
Published: April 2015

Experimental tests of a turbine-powered, self-propelled, high-speed railcar are presently being conducted on a section of the Long Island Railroad. This paper describes the railcar, the unique gas turbine power plant and mechanical drive system, and the expected railcar performance. The objectives of the demonstration program, the merits of the selected turbomechanical drive system, and the market potential for production turbine-powered railcars are discussed. A summary of test experience to date and a preview of propulsion-system innovations that may be tested in follow-on programs are presented.
A Comparison of Oil and Gas Lubrication Systems for Closed-Loop Gas-Turbine Machinery
Authors: Curwen P. W. , Harmon R. A. , Manning G. B.
Published: April 2015

Most gas turbines in service today have oil-lubricated bearings. However, when these machines are utilized in closed-loop applications (where the cycle gas is continuously recirculated), means must be provided to insure that the lube oil cannot leak into the cycle gas. The criticality of this problem has led, in some instances, to complete elimination of the problem by use of process-fluid lubrication wherein cycle gas is used as the bearings lubricant. This paper describes design and operational experience with both oil-lubricated and gas-lubricated closed-loop gas-turbine machinery. Comparison of the two lubrication concepts reveals the inherent potential advantages of gas lubrication in terms of system simplicity and reliability.
Gas Turbine Propulsion Machinery for the MSTS Roll-On/Roll-Off Ship
Authors: Caldera Donald L. , Swensson Gerald C. , Hoch Charles E.
Published: April 2015

The history of the roll-on/roll-off type of cargo ship is reviewed to illustrate the development of the specific ship requirements for the Adm. Wm. M. Callaghan. The ship is unique in that it is the first large cargo ship to be built which has been initially designed to incorporate all advantages of gas turbine propulsion. The basic engineering problems and selections involved in the design of the machinery plant are briefly described. The service performance of this ship will have a significant influence on future applications of gas turbine machinery for commercial ships.
Operating Gas Turbines in a Gas Processing Plant
Authors: Byrnes Eugene B. , McCrary Donald H. , Darnell Quinton L.
Published: April 2015

In their gas processing plant on the Texas Gulf Coast the authors’ company recently converted from their original power source to two gas turbine units. This paper describes the equipment and reviews its installation, inlet and exhaust systems, maintenance, operation, and comparative cost. Based on this experience, the authors propose several changes for future installations.
Creole’s 50 Industrial Gas Turbines in Repressuring Service
Authors: Sanborn L. B.
Published: April 2015

This paper describes the application of gas turbines to crude-oil production in a Venezuelan underwater reservoir. Decreasing pressure caused a gradual slowing down of the natural flow, and Creole Corporation was faced with the problem of either artificial lifting of the crude or curtailment of operations with several years of ample supply remaining untapped. This challenge was met successfully through repressurization of the wells by gas turbines. The design of these turbine facilities, their operation, and some of the problems involved are described. The author summarizes with a review of the performance of the gas turbines at their various locations.
Thermal Efficiency Versus Engine Price: Optimizing for Industrial Vehicles
Authors: Kahle Glenn W. , Wright Edward S.
Published: April 2015

The profitability of the turbine engine in industrial vehicles is evaluated by a computer analysis which simulates engine and vehicle performance. Total operating cost is used as the basis for comparison. Results show industrial vehicles with current simple-cycle turbine engines are only marginally competitive with diesel-powered vehicles because of higher initial cost and higher fuel consumption. The requirements of a competitive turbine engine showing the trade-off between thermal efficiency and initial price are presented. Methods investigated of increasing thermal efficiency include increased turbine inlet temperatures, increased pressure ratios, closed-cycle waste-heat recovery system, and regeneration. An initial price is established for each of these higher efficiency cycles to be competitive. From these results, promising areas of development are identified.
Recent Sea-Salt-in-Air Implications as Highlighted by Marine Gas Turbine Requirements
Authors: Kaufman R. E. , Pollini R. J.
Published: April 2015

Marine gas turbines are vulnerable to damage caused by the induction of salt-laden air. The compilation of data on sea-salt-in-air has been going on for years, but these data, except for a small fraction, cover only average concentrations; very little sampling has been done during high-velocity wind conditions. The authors describe their field trips on various naval vessels and the difficulties they encountered in attempting to collect sample deposits of heavy concentration. Their findings are given, and some proposals are made to facilitate collection of this kind of data in the future.
Process Air Extraction From a Gas Turbine
Authors: Husen P. C.
Published: April 2015

This paper describes a unique and successful application of a gas turbine in a petrochemical plant. In addition to driving a hydrocarbon compressor and furnishing hot exhaust gas for waste-heat recovery, the gas turbine furnishes process air at approximately 50 psig. A larger gas turbine than required by compressor load was purchased to provide the necessary air.
Design of Compressor Blades Suitable for Transonic Axial-Flow Compressors
Authors: Boyce M. P.
Published: April 2015

This paper deals with the development of a blade profile suitable for transonic axial-flow compressors. Development of new incidence and deviation rules incorporating thickness, Mach numbers, and position of maximum thickness corrections are fully explained. In addition, a step-by-step analysis for the calculation of the blade profile for a transonic compressor is presented. The design method outlined is easily adaptable for the digital computer. A flow chart of the procedure to facilitate programming has also been included.
Jet Engine Starters, Cartridge-Pneumatic
Authors: Anderson J. A. , Galasinski C. R.
Published: April 2015

A typical dual-mode (cartridge-pneumatic) jet engine starter is discussed with respect to its basic design and functional purpose. The establishment of starter output requirements for satisfactory engine starting is presented as an aid to understanding the design problem encountered for a jet engine starter. Discussion of energy conversion and particular design parameters concentrates on the cartridge mode of operation and the handling of the high-temperature, high-pressure gas produced by the starter cartridge.
The Effects of Microstructural Variations on Stress-Corrosion Cracking Susceptibility of Ti-8Al-1Mo-1V Alloy on Marinized Gas Turbines
Authors: Danesi W. P. , Sprague R. A. , Donachie M. J.
Published: April 2015

Salt can cause titanium alloys to crack, and if long-time operation of titanium hardwares in salt atmospheres is expected, effective means must be found to eliminate or control this tendency. The authors describe in detail their stress-corrosion testing of titanium alloys, and the results are plotted in a number of tables. Figures show stress-versus-temperature charts at different high temperatures, and the microstructure of the alloy after testing is illustrated. The results of the tests are evaluated and a brief summary is given.
Fuels for Marine Gas Turbines
Authors: Cabal A. V. , Warren J. H.
Published: April 2015

Fuel properties that affect marine gas turbine operation are discussed. Particular emphasis is given to fuel-contamination factors, including (1) fuel contaminants affecting engine performance; (2) test procedures for measuring fuel contamination; (3) sources of fuel contamination; and (4) prevention of fuel contamination.
Fuel Problems With Marine Gas Turbine Engines
Authors: Attiani J. P.
Published: April 2015

This paper describes a test program undertaken by the Navy to determine the causes of two problems in the fuel-oil systems of gas turbine engines. The first problem concerns short filter life; the second, copper deposits that cause clogging of fuel-oil nozzles. Results are given for operating experience with va-ious filter units from both laboratory tests and fleet experience. The effect of copper deposits on thermal stability is discussed. The author concludes with a review of remedial actions being taken to solve these problems.
Supplementary Firing of Gas Turbine Exhaust Systems
Authors: Gjerde Ed
Published: April 2015

Several factors require consideration in designing the most effective supplementary fired waste-heat recovery system. Among the problems for which solutions must be found are temperature profile going into the waste-heat recovery unit, flame length and stability, effect of laminar flow characteristics of exhaust streams, effects of radiation on exhaust temperature profiles, exhaust-duct velocity limitations, and the adverse effects of flame impingement on the waste-heat recovery equipment. The results obtained from a series of tests to determine the optimum system design are described briefly.
Working Fluid as a Design Variable for a Family of Small Rankine Power Systems
Authors: Bjerklie John W.
Published: April 2015

Many different Rankine-cycle working fluids were considered in sizing turbomachinery for power levels from 50 w to 10 kw. It was found that by using three working fluids over the spectrum of applications that good performance could be achieved over the power range when peak temperature varied between 160 and 1000 F, and sink temperature varied between −65 and 635 F. These operating conditions can be met with as few as three turbine sizes when operating speed is allowed to vary to fit the application. Only one shaft, bearing, and basic support structure is needed for the family.
Metallurgical and Fluid Dynamic Results of a 2000-Hour Endurance Test on a Two-Stage, 200-Horsepower Turbine in Wet Potassium Vapor
Authors: Zimmerman W. F. , Rossbach R. J.
Published: April 2015

In a potassium Rankine-cycle technology program concerned with the life and performance of turbines in wet potassium vapor, a two-stage turbine has been designed, built, and performance tested in potassium vapor up to a temperature of 1580 F. Subsequently, a 2000-hr endurance test was completed at 1500 F with the objectives of determining the relative erosion resistance of refractory blading materials, the degradation in turbine performance with erosion, if any, and the contamination effects on selected refractory alloys in a Type 316 stainless steel facility. Performance was unaffected in 2000 hr of testing. Although minor liquid-metal corrosion of turbine blades was noted, no impact erosion occurred on turbine components. Some evidence of mechanical damage by liquid-drop impact or by cavitation was observed in test-specimen inserts behind the second stage. The 2000-hr test indicated the adequacy of a Type 316 stainless steel potassium turbine test facility for development testing of space power turbines with molybdenum alloy components.
Two Years Experience of a Gas Turbine Firing Residual Fuel
Authors: Nakao Kozaburo , Hirai Harumi , Omori Toshiji
Published: April 2015

A 15-Mw gas turbine unit, using residual oil, commenced service operation on October 1965. By the end of June 1967, this plant accumulated a total servicing operation of 12,081 hr at almost maximum rating and performed 99.6 percent of reliability factor. In order to observe the tendency of corrosion and contamination due to fuel ashes, inspections of hot parts were carried out at every 3 to 4 months. The experiences during this service operation are reported in this paper.
Heat-Exchanger Optimization for a Regenerative Small-Gas-Turbine Cycle
Authors: Demetri E. P.
Published: April 2015

A systematic approach to the problem of determining the optimum regenerator design for any given application is described. The proposed method can be used to determine the optimum regenerator when all pertinent tradeoffs are known or to aid in quantitatively assessing the importance of those tradeoff factors which cannot be evaluated at the outset of a system design. The general procedure is discussed in terms of a specific illustrative example involving the optimization of a regenerator in a typical small-gas-turbine cycle for automotive applications. Although the optimization procedure is illustrated by means of a specific example, it is sufficiently general to be applied to any situation in which the optimum design of a compact heat exchanger must be determined. For example, any of the commonly used configurations of compact heat-transfer surfaces, such as plate fin, tubular, or rotary, can be considered. In addition, the optimization can be carried out on the basis of any one of a wide variety of criteria, such as minimum cost or weight. With this in mind, the results of the studies described lead to a number of useful conclusions regarding the general philosophy and practice of regenerator optimization.
Spey Combustion-Development for Military Applications
Authors: Gradon K. , Miller S. C.
Published: April 2015

The history of the Spey engine is unusual in that it first saw service in civil applications and later was adapted for a variety of military aircraft. Although varying emphasis is placed on certain aspects of combustion performance depending on the role of the engine, it has been the aim of the development program to produce a common combustion specification of a sufficiently high standard to meet all demands. In this historical survey, extending from the background of earlier designs to current civil and military service, all areas of performance are mentioned, but particular attention is given to the problem of exhaust smoke.
Emulsified Fuel for Military Aircraft
Authors: Nixon J. , Wallace T. J. , Beerbower Alan
Published: April 2015

An analysis of statistics of aircraft crashes shows that approximately 70 percent of the fatalities are due to fire. The fire hazards in a crash situation are largely associated with liquid fuel. These problems may be either minimized or eliminated by thickening the fuel. This paper summarizes work carried out under an Army contract (DA 44-177-AMC-387(T)) aimed at the formulation of JP-4 fuel emulsions which reduce the fire hazards associated with liquid JP-4. Two JP-4 emulsions (designated WSX-7063 and WSX-7165) which appear to meet the study contractual requirements possess 99 percent of the fuel value associated with JP-4; they reduce the rate at which combustible vapors are released; they have yield stresses which will retard flow through a tank puncture; they are stable over the temperature range of −20 F to 130 F (WSX-7165 is stable over the range of −65 F to 160 F); and they are compatible with aircraft materials of construction. WSX-7165 is being made in 1000-gal batches and it is under evaluation by various engine manufacturers. The fuel has also been tested in several simulated crash situations and the results were quite favorable.
DIGATEC (Digital Gas Turbine Engine Control)
Authors: Bayati J. E. , Frazzini R. M.
Published: April 2015

The basic operating principles of an electronic digital computer gas turbine engine control system are presented. Closed loop turbine discharge temperature and speed controls have been implemented; their feasibility was demonstrated through hybrid digital/analog simulation and actual tests of a GE J85 turbojet engine through the start mode to maximum afterburner. Control mode description and results of the analysis and experimental runs are given in this paper.
Electroslag Remelted Superalloys for Gas Turbine Engines
Authors: Johnson H. A. , Bhat G. K.
Published: April 2015

At the present time, virtually all superalloys used in Soviet gas turbine engines have been electroslag remelted. The use of this process in the United States has been at a virtual standstill since its inception by Hopkins in 1935. This paper will cover recent development effort on the process and what it offers to the industry. The process itself will be described in detail. Included also will be its advantages, both in metalworking and resultant mechanical properties obtained on actual gas turbine engine components fabricated from electroslag remelted superalloys.
Hydraulic Starting of Marine Gas Turbine Engines
Authors: Jennings L. C. , Misulis E. V.
Published: April 2015

Hydraulic starting is currently being used on several major ships employing gas turbine power. The system designs, as well as the basic principles of hydraulic starting, are discussed in this paper.
The Contribution of Metallic and Ceramic Coatings to Gas Turbine Engines
Authors: Barnhart R. E.
Published: April 2015

Metallic and ceramic coatings enhance the quality of today’s gas turbine engines by enabling them to run longer and by increasing their reliability and efficiency of operation. Coatings give design engineers more latitude in their choice of materials for high-performance applications. Discussed here are the characteristics of coatings produced by three different means: detonation-gun process, plasma process, and diffusion process. By considering the following three parameters: (a) the nature of wear and corrosion problems in gas turbine engines, (b) the results of coated components in commercial service, and (c) the cost savings attributable to coatings, we can develop guidelines for even more effective use of coatings in the future.
The Influence of Chemical Inhibitor Addition on Reverse-Jet Flame Stabilization
Authors: Bellamy L. , Barron C. H. , O’Loughlin J. R.
Published: April 2015

Flame stability limits produced by a reverse-jet flameholder are experimentally studied with a chemical inhibitor added to the gas stream issuing from the reverse-jet. The result of this addition is a reduction of flame stability limits. Such a reduction indicates the importance of the chemical rate processes in the flameholding phenomenon.
The V/STOL Aircraft Environment
Authors: Spooner S. H.
Published: April 2015

A brief review is made of the flow pattern surrounding V/STOL aircraft utilizing various propulsion concepts during tests of these aircraft in close proximity to the terrain. Specific problems encountered by the propulsion systems and caused by the character of the flow are described together with the fixes employed. Ground surface debris and hot gas reingestion effects are the primary consideration.
Air Starting Systems for Marine Gas Turbine Engines
Authors: Garner P. B. , Fulmer B. A.
Published: April 2015

The advent of large gas turbine engines aboard marine vehicles has created a demand for starting systems suitable for marine application. This paper discusses marine requirements and describes and discusses applicable pneumatic starting systems. In addition, a comparison between pneumatic and other starting methods will be presented.
An Optimum Application of Austenitic Nodular Iron for Gas Turbine Components
Authors: Hageboeck J. T. , Roberts W. S.
Published: April 2015

A new modification of an economical casting material is presented for use in the intermediate temperature range, which is considered to be 800 to 1300 F. An illustration is given of two large castings actually produced for the 1500-hp ATAC regenerative gas turbines engine. Comparisons are made with other materials, giving information stress-rupture at various temperature levels and some cost information. Also included are design suggestions for better utilization of foundry techniques.
Peaking Capacity for Pennsylvania Power & Light Company
Authors: Curley C. C.
Published: April 2015

This paper, composed of two parts, deals with the installation and operation of peaking and emergency generating facilities for the Pennsylvania Power & Light Co. system. The first part covers fourteen 16-Mw packaged type combustion turbine generators which are installed in two groups of four units and three groups of two units. The second part covers the repowering of an existing 35-Mw hydrogen-cooled generator with three jet engines.
A Circumferentially Oriented Modular Gas Turbine Recuperator
Authors: McDonald C. F.
Published: April 2015

This paper gives a brief description of a circumferentially oriented modular gas turbine recuperator. The basic module is of the plate-fin type, and is made from an assembly of radially tapered secondary surfaces to form a segmental matrix with a counterflow fluid configuration. The removable modules are integrated with the axial turbomachinery to form a compact package. Some of the economic, design, manufacturing, and performance experiences gained during the development of this heat exchanger are discussed in detail.
A 2000-HP Military Vehicle Gas Turbine: A Study of Significant Thermodynamic and Mechanical Parameters
Authors: Carter A. F.
Published: April 2015

During a study of possible gas turbine cycles for a 2000-hp unit for tank propulsion, it has been established that the level of achievable specific fuel consumption (sfc) is principally determined by the combustor inlet temperature. If a regenerative cycle is selected, a particular value of combustor inlet temperature (and hence sfc) can be produced by an extremely large number of combinations of compressor pressure ratio, turbine inlet temperature, and heat exchanger effectiveness. This paper outlines the overall design considerations which led to the selection of a relatively low pressure ratio engine in which the turbine inlet temperature was sufficiently low that blade cooling was not necessary.
Metallurgical Development for Added Reliability of Industrial Gas Turbine Rotating Blades
Authors: Wall F. J.
Published: April 2015

Increased reliability of industrial gas turbine rotating blades in the hot section of turbines has been achieved by utilization of advanced metallurgical techniques. These techniques include vacuum melting master alloy heats, minimizing residual stresses in blades after machining, and increasing the quality of nondestructive inspection of blades during and after fabrication. In addition, long time stress-rupture tests, corrosion evaluation, and microstructural studies on advanced alloys have provided necessary information for selection of turbine blade alloys for future generations of turbines.
Governing Gas Turbine Engines for Marine Propulsion: Power Versus Speed Control
Authors: O’Neil D. A.
Published: April 2015

This paper examines typical shipboard operational requirements, conventional marine propulsion control methodology, and the related merits of power and speed governing for the aircraft derived marine gas turbine engine applications of the future.