bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a 220-MW Coal-Fired Combustion Turbine Combined Cycle: Current Status
Authors: Pillsbury P. W. , Bannister R. L. , Diehl R. C. , Loftus P. J.
Published: March 2015

In the eight-year, multicontractor program to develop a 220-MW coal-fired combustion turbine combined cycle plant, the team is now into its third year of subscale slagging combustor testing. Because of an ability to accept unbeneficiated, utility-grade coal, the slagging combustor is the key to the direct coal-fired combustion turbine. The projected plant will contain two 80-MW combustion turbines equipped with slagging combustors, two heat recovery steam generators, and a 65-MW steam turbine.

In testing to date, the concept has demonstrated its ability to handle high- and low-sulfur bituminous coals, and low-sulfur subbituminous coal. Feeding the fuel in the form of pulverized coal has proven to be superior to coal-water mixture type feed. The program objectives relative to combustion efficiency, combustor exit temperature, NOx emissions, carbon burnout, and slag rejection have been met. Work continues to reduce alkali, particulate, and SOx levels leaving the combustor. Parametric studies have been made that focus on the latter two problems. They indicate that faster, more thorough slag removal between the rich and lean stages is the path toward achieving lower emission of SOx, alkali, and particulates. New components have been added to the subscale combustor for this purpose.
Ceramic Filters for Use at High Temperature
Authors: White Lloyd R.
Published: March 2015

A new hot gas filter for removal of particulates upstream of gas turbines is described and compared with a device called a candle. Candle filters are made in the shape of a large test tube from ceramic materials bonded with a glassy phase. The filtering membrane is fairly thick making candles relatively heavy. A thinner filter would be easier to support, more tolerant of thermal shock, and would offer less resistance to flow. A filter of a ceramic/ceramic composite may achieve these goals and specimens are being fabricated by depositing a ceramic material on a ceramic fiber preform by chemical vapor infiltration. The ceramic matrix is silicon carbide and the ceramic fiber reinforcement is alumina-boria-silica. Progress toward filter development is described.
One-Dimensional, Stage-by-Stage, Axial Compressor Performance Model
Authors: Johnson Mark S.
Published: March 2015

This paper presents a description of a one-dimensional, constant-radius, stage-by-stage (blade-element) axial compressor model used for compressor map generation and gas turbine off-design performance prediction. This model is designed for investigators who are without access to the proprietary compressor performance information of the gas turbine manufacturers but who are nevertheless interested in predicting the off-design performance of large utility gas turbine power systems. Model performance results (compressor maps) are reported for simulation of a nineteen-stage axial compressor designed by Allison Gas Turbine for the Electric Power Research Institute. The model is further demonstrated by simulating the NACA Eight Stage compressor. The resulting compressor maps are in good qualitative agreement with published maps and are useful for gas turbine power system performance simulation studies. This general-purpose modeling procedure can be applied to any axial compressor for which sufficient airfoil geometry and design-point performance information is known.
High Temperature Erosion Resistance of Coatings for Gas Turbine
Authors: Tabakoff W. , Hamed A. , Metwally M. , Pasin M.
Published: March 2015

An experimental investigation was conducted to study the ash particle rebound characteristics and the associated erosion behavior of superalloys and aluminide coatings subjected to gas-particle flows at elevated temperatures. A three-component LDV system was used to measure the restitution parameters of 15 micron mean diameter coal ash particles impacting some widely used superalloys and coatings at different angles. The presented results show the variation of the particle restitution ratios with the impingement angle for the coated and uncoated superalloys. The erosion behaviors of INCO-738, MAR 246 and X40 superalloys and protective coatings C, N, RT22 and RT22B have also been investigated experimentally at high temperatures using a specially designed erosion tunnel. The erosion results show the effect of velocity, temperature and the impact angle on the erosion rate (weight loss per unit weight of particles). Based on the experimental results of the particle mass effect on both weight losses and erosion rates, the coating lives have been estimated for different particle concentrations.
An Approach for Evaluation of Gas Turbine Deposition
Authors: Wenglarz Richard A.
Published: March 2015

An approach for estimating deposition in gas turbines is described. This approach extrapolates deposition data from lower cost experiments than turbine engine or cascade tests. The purpose is a method to screen candidate fuels and turbine protection methods so that only the most promising need be evaluated in turbine tests. The deposition approach is applied to estimate deposition maintenance intervals for a tested fuel, evaluate benefits of hot gas cleanup, and provide fuel screening criteria.
Aerodynamics of Bluff Body Stabilized Confined Turbulent Premixed Flames
Authors: Pan J. C. , Vangsness M. D. , Ballal D. R.
Published: March 2015

Detailed information on the influence of geometric and flow parameters on the structure and properties of recirculation zone in confined combusting flows is not available. In this paper, recirculation zone structure and turbulence properties of methane-air mixtures downstream of several conical flameholders were measured using LDA. These tests employed different blockage ratios (13% and 25%), cone angles (30, 45, 60, and 90 degrees), equivalence ratios (0.56, 0.65, 0.8, and 0.9), mean annular velocities (10, 15, and 20 m/s), and approach turbulence levels (2%, 17%, and 22%).

It was found that increasing the blockage ratio and cone angle affected the recirculation zone size and shape only slightly. Also, these parameters increased the shear stress and turbulent kinetic energy (TKE) moderately. Increasing the equivalence ratio or approach turbulence intensity produced a recirculation zone shape very similar to that found in the cold flow. TKE decreased due to turbulent dilatation produced by increased heat release. These observations are discussed from the viewpoint of their importance to practical design and combustion modeling.
Optimal State Space Control of a Gas Turbine Engine
Authors: Watts J. W. , Dwan T. E. , Brockus C. G.
Published: March 2015

An analog fuel control for a gas turbine engine was compared with several state space derived fuel controls. A single spool, simple cycle gas turbine engine was modeled using ACSL (high level simulation language based on FORTRAN). The model included an analog fuel control representative of existing commercial fuel controls. The ACSL model was stripped of non-essential states to produce an 8 state linear state space model of the engine. The A, B, and C matrices, derived from rated operating conditions, were used to obtain feedback control gains by the following methods: (1) state feedback; (2) LQR theory; (3) Bellman method; and (4) polygonal search. An off-load transient followed by an on-load transient was run for each of these fuel controls. The transient curves obtained were used to compare the state space fuel controls with the analog fuel control. The state space fuel controls did better than the analog control.
Shop Test Result of V64.3 Gas Turbine
Authors: Jansen M. , Schulenberg T. , Waldinger D.
Published: March 2015

The V64.3 60MW combustion turbine is the first of a new generation of high temperature gas turbines, designed for 50 and 60Hz simple cycle, combined cycle and cogeneration applications. The prototype engine was tested in 1990 in the Berlin factories under the full range of operation conditions. It was equipped with various measurement systems to monitor pressures, gas and metal temperatures, clearences, strains, vibrations, and exhaust emissions. The paper describes the engine design, the test facility and instrumentation, and the engine performance. Results are given for turbine blade temperatures, compressor and turbine vibrations, exhaust gas temperature, and NOx emissions for combustion of natural gas and fuel oil.
Repowering Application Considerations
Authors: Brander Jon A. , Chase David L.
Published: March 2015

As utilities plan for load growth in the 1990’s, they are faced with the difficulty of choosing the most economic generation while subject to a number of challenging constraints. These constraints include environmental regulations, particularly the new Clean Air Act, risk aversion, fuel availability and costs, etc. One of the options open to many utilities with existing steam units is repowering, which involves the installation of gas turbine(s) and heat recovery steam generator(s) (HRSG) to convert the steam plant to combined-cycle operation. This paper takes an overall look at the application considerations involved in the use of this generating option, beginning with a summary of the size ranges of existing steam turbines that can be repowered using the GE gas turbine product line. Other topics covered include performance estimates for repowered cycles, current emissions capabilities of GE gas turbines, approximate space requirements and repowering economics.
Application of Flash Welding to a Titanium Aluminide Alloy-Microstructural Evaluations
Authors: Gould J. E. , Stotler T. V.
Published: March 2015

Alpha-two titanium aluminides represent strong candidates for replacing many conventional titanium and nickel-base superalloys for intermediate temperature applications. One potential application of these alloys is turbine engine rings. Nonrotating rings of this type are typically manufactured by flash butt welding. The performance of welds in this alloy are known to be strongly affected by the weld microstructure. Welding processes that result in very slow cooling rates yield relatively coarse Widmanstatten-type microstructure(s) which generally yields acceptable weld performance. Processes that result in intermediate cooling rates, however, result in acicular alpha-two martensite microstructures. These microstructures have very little ductility and lead to reduced weld performance. Finally, for processes where the cooling rate is very rapid, the weld microstructure is a retained ordered beta phase, which apparently results in improved weld properties.
Weak Extinction Limits of Large Scale Flameholders
Authors: Baxter M. R. , Lefebvre A. H.
Published: March 2015

Weak extinction data obtained from an experimental apparatus designed to simulate the characteristics of practical afterburner combustion systems are presented. The apparatus supplies mixtures of varied composition (equivalence ratio and degree of vitiation), temperature and velocity to Vee-gutter flame holders of various widths and shapes similar to those found in jet engine systems. The fuel employed is a liquid hydrocarbon whose chemical composition and physical properties correspond to those of aviation kerosine, JP5. An equation for predicting weak extinction limits which accounts for upstream vitiation and the chemical characteristics of the fuel is derived from stirred reactor theory. The correlation between the predictions and experimental results indicates that the stirred reactor approach can provide a framework for predicting the lean blowout limits of practical flameholders over wide ranges of engine operating conditions.
Noise Control Technology With Reference to Natural Gas Compressor Stations Under the Aspect of Investment Costs
Authors: Schneider Manfred , Mann Jürgen
Published: March 2015

For the conveyance and storage of natural gas, compressor stations are required where the installed power output varies mostly between 1 MW and 20 MW.

The noise control measures involved to meet the environmental noise immission regulations in Europe will be presented.

The most economical methods of noise control techniques are described particularly for the intake system and the exhaust system of gas turbines, the housing of such engines and for peripheral sound sources like gas coolers, oil coolers and the above ground piping.
The Design, Fabrication and Installation of a Quiet Compressor Station
Authors: Humphries Ed , Schulz David , Binek John
Published: March 2015

Stringent environmental constraints are usually associated with or applied to the siting and installation of new pipeline facilities. This has resulted in a significant portion of the design effort and ultimate cost of the facility to be dedicated to the mitigation of these environmental concerns. This paper describes how a compressor station can be designed and built such that stringent silencing requirements can be satisfied. The paper also references specific aspects of design which were successfully applied to the Parkway Compressor Station, Canada.
A Chambered Porous Damper for Rotor Vibration Control: Part II — Imbalance Response and Bladeloss Simulation
Authors: Walton J. , Martin M.
Published: March 2015

In this paper, results of experimental rotordynamic evaluations of a novel, high load chambered porous damper design, are presented. The chambered porous damper concept was evaluated for gas turbine engine application since this concept avoids the non-linearities associated with high eccentricity operation of conventional squeeze film dampers. The rotordynamic testing was conducted under large steady state imbalance and simulated transient bladeloss conditions for up to 0.254 mm (0.01 in) mass c.g offset or 180 gm-cm (2.5 oz-in) imbalance. The chambered porous damper demonstrated that the steady state imbalance and simulated bladeloss transient response of a flexible rotor operating above its first bending critical speed could be readily controlled. Rotor system imbalance sensitivity and logarithmic decrement are presented showing the characteristics of the system with the damper installed. The ability to accommodate high steady state and transient imbalance conditions make this damper well suited to a wide range of rotating machinery, including aircraft gas turbine engines.
Electromechanical Simulation and Testing of Actively Controlled Rotordynamic Systems With Piezoelectric Actuators
Authors: Lin Reng Rong , Palazzolo A. B. , Kascak A. F. , Montague G. T.
Published: March 2015

Past research on this subject has treated piezoelectric actuators as ideal devices that have tip displacements proportional to their input voltages, at any instant in time. This assumption neglected phase lag and amplitude change at high frequencies. This characteristic of any actuator may lead to coupled control system-structural system instability that limits the amount of active stiffness or active damping that can be obtained. The paper presents a method for simulating the coupled “electromechanical” system to predict rotordynamic stability and unbalance response along with control system stability. The piezoelectric actuators and their amplifiers are represented as equivalent linear electrical circuits. The electromechanical system modeling approach is utilized to correlate test results from a double overhung rotor rig at NASA Lewis. The test results also show the effectiveness of the control system for suppressing the unbalance response of two modes using active stiffness and active damping.
Evaluation of NOx Mechanisms for Lean, Premixed Combustion
Authors: Corr Robert A. , Malte Philip C. , Marinov Nick M.
Published: March 2015

The formation of the oxides of nitrogen, NOx, is examined through experiments and chemical kinetic modeling for lean, premixed combustion in a laboratory, atmospheric pressure, jet-stirred reactor. The experimental conditions are as follows: fuel-air equivalence ratio (ϕ) of 0.6, temperatures of 1460 to 1730 K, and reactor loadings of 20 to 150 kg/sec-m3-atm2, which correspond to reactor mean residence times of 11.4 to 1.8 milliseconds. Two fuels are examined: ethylene, because of its importance as a combustion intermediate, and methane, because of its importance as a component of natural gas. Besides the premixed operation, the reactor is also operated non-premixed. For both modes, the NOx increases with decreasing loading, from about 3–4 ppmv at the highest loading to about 11–21 ppmv at the lowest loading for the ethylene fuel. This increase in NOx occurs because a hot spot develops on centerline when the reactor is lightly loaded. Also for the lowest loading, the non-premixed mode produces about twice as much NOx as the premixed mode, i.e., about 21 versus 11 ppmv. At the other reactor loadings, however, because of the intense mixing, the NOx levels are only slightly elevated for the non-premixed mode compared to the premixed mode. Upon switching to methane fuel, the NOx decreases by about 25%.

The major finding of this study is that prompt NO is the predominant mechanism for the NOx formed. The other mechanisms considered are the Zeldovich and nitrous oxide mechanisms. Furthermore, the amount of NOx measured and modeled agrees almost exactly with the extrapolation of Fenimore’s (1971) original prompt NO data to the present conditions of ϕ = 0.6. Although Fenimore conducted his experiments with porous plate and Meker-type burners for 0.8 ≤ ϕ ≤ 1.7, our findings show that his results apply well to high-intensity, lean combustion. In the gas turbine literature, e.g. see Shaw (1974) and Toof (1985), Fenimore’s results are expressed as:(1)NO/(NO)equil=P1/2func(ϕ)It is func (ϕ) that extrapolates well to our conditions. This finding indicates that func (ϕ) applies to laboratory burners of widely different mixing intensity, i.e., from Fenimore’s burners with structured flame fronts to our high-intensity burner with dispersed reaction. In our opinion this finding strengthens the justification of using func (ϕ) for the prediction of NOx formation in practical combustors, including lean, premixed combustors.
Design and Evaluation of Silicon Nitride Turbocharger Rotors
Authors: Takama Kenichiro , Sasaki Syoji , Shimizu Tetsuji , Kamiya Nobuo
Published: March 2015

Two types of silicon nitride ceramic rotors have been introduced into the Japanese market by Toyota Motor Corporation, which are named CT26 and CT12A, to improve engine acceleration response by the reduction in moment of inertia. In order to design a suitable blade shape for ceramic rotor ,the critical stress of blade was determined by the results obtained experimentally from correlating the fracture origin of over spin-tested rotors with centrifugal stress at fracture.

A suitable blade shape has been determined for the CT26 turbocharger rotor type, which is identical to the metal rotor except for the disc diameter of hub back face and the blade thickness. The CT12A type is of similar design to the CT26 type, all dimensions could reduce except for the inlet blade thickness, which is determined by foreign object damage ( FOD )resistance.
A Procedure for Automated Gas Turbine Blade Fault Identification Based on Spectral Pattern Analysis
Authors: Loukis E. , Mathioudakis K. , Papailiou K.
Published: March 2015

A method for diagnosing the existence and the kind of faults in blades of a Gas Turbine compressor is presented in the present paper. The innovative feature of this method is that it performs the diagnosis automatically, namely it gives a direct answer to whether a fault exists and what fault it is, without requiring the interpretation of results by a human expert. This is achieved by the derivation of the values of discriminants calculated from spectral patterns of fast response measurement data. A decision about the corresponding Engine status is then derived according to the values of these discriminants. In the paper, the procedure of examining the suitability of particular parameter discriminants and the constitution of a related knowledge base is described. The way of derivation of decisions by a computer, on what engine condition a particular measurement data set corresponds, is then described.
Discharge Coefficients of Cooling Holes With Radiused and Chamfered Inlets
Authors: Hay N. , Spencer A.
Published: March 2015

The flow of cooling air within the internal passages of gas turbines is controlled and metered using orifices formed of holes in discs and casings. The effects of inlet radiusing and chamfering of these holes on the discharge coefficient forms the subject of this paper. Experimental results for a range of radiusing and chamfering ratios for holes of different length to diameter ratios are presented covering the range of pressure ratios of practical interest.

The results indicate that radiusing and chamfering are both beneficial in increasing the discharge coefficient. Increases of 10–30% are possible. Chamfered holes give the more desirable performance characteristics in addition to being easier to produce than radiused holes.
Self-Induced Flow in a Stepped Rotating Tube
Authors: Gilham S. , Ivey P. C. , Owen J. M.
Published: March 2015

Self-induced flow occurs when a tube, open at one end and sealed at the other, is rotated about its central axis: fluid flows along the axis from the open end towards the sealed end and returns in a layer adjacent to the inner surface of the tube. This mechanism, which can occur under isothermal or nonisothermal conditions, is believed to be responsible for the so-called “hot-poker effect” that was observed during anti-icing tests on the nose bullet of an aeroengine.

This paper describes a combined theoretical and experimental study of self-induced flow. It is shown that, for the length-to-diameter (L/D) ratios and rotational Reynolds numbers associated with the anti-icing tubes of aeroengines, the laminar flow near the sealed end of the tube is similar to that of the so-called free disc. Swirl in the air outside the open end reduces the self-induced flow, but flow can reach the sealed end of a stepped tube which has either a sudden contraction or a sudden enlargement.
Film Cooling on a Gas Turbine Rotor Blade
Authors: Takeishi Kenichiro , Aoki Sunao , Sato Tomohiko , Tsukagoshi Keizo
Published: March 2015

The film cooling effectiveness on a low-speed stationary cascade and the rotating blade has been measured by using a heat-mass transfer analogy. The film cooling effectiveness on the suction surface of the rotating blade fits well with that on the stationary blade, but a low level of effectiveness appears on the pressure surface of the rotating blade. In this paper, typical film cooling data will be presented and film cooling on a rotating blade is discussed.
Blade Row Interaction in a Multistage Low-Pressure Turbine
Authors: Arndt N.
Published: March 2015

The objective of this work was to enhance the understanding of unsteady flow phenomena in multistage low-pressure turbines. For this purpose, hot-film probe measurements were made downstream of every rotor blade row of a five-stage low-pressure turbine. Rotor-rotor interaction and stator-rotor interaction were observed to have a profound influence on the flow through the low-pressure turbine. Interaction of rotors of different turbine stages occurred owing to the influence of the wakes shed by one rotor blade row upon the flow through the next downstream rotor blade row. This wake-induced rotor-rotor interaction resulted in strongly amplitude-modulated periodic and turbulent velocity fluctuations downstream of every rotor blade row with the exception of the most upstream one. Significantly different wake depths and turbulence levels measured downstream of every rotor blade row at different circumferential positions evidenced the effect of the circumferentially nonuniform stator exit flow upon the next downstream rotor blade row. Stator-rotor interaction also strongly influenced the overturning and the underturning of the rotor wakes, caused by the rotor secondary flows, in the rotor endwall regions. Low rotor wake overturning and underturning, i.e., reduced rotor secondary flow influence, were observed to correlate well with low rotor wake turbulence levels.
Performance Gains Derived From Water Injection in Regenerative, Indirect-Fired, Coal-Fueled Gas Turbines
Authors: Parsons Edward L. , Bechtel Thomas F.
Published: March 2015

This paper discusses the performance benefits available from compressor discharge water injection in an indirect-fired gas turbine. The results of parametric performance studies are the main technical focus. The performance studies are part of the U.S. Department of Energy (DOE) Morgantown Energy Technology Center (METC) indirect-fired gas turbine program. The key technical approach is to develop a high-pressure, coal-fired ceramic heat exchanger to serve as the air heater.

A high-pressure coal-fired ceramic air heater is now under development in a DOE-sponsored program at Hague International. The goal of this program is to develop a heat exchanger suitable for turbine inlet temperatures from 1,100 to 1,260 °C. With a turbine inlet temperature in this range, coal-fired indirect systems have performance superior to direct-fired gas-fueled simple cycle systems. Using conservative assumptions, the coal-fired indirect cycle has calculated net plant efficiencies in the 32 to 37 percent range, on a higher heating value (HHV) basis, at typical pressure ratios and 1,260 °C (2,300 °F) turbine inlet temperature. Adding a steam bottoming cycle raises the net plant efficiency (NPE) to 44–48 percent HHV. Adding water injection raises the simple cycle efficiency to 41–43 percent HHV and the combined cycle efficiency to 47–54 percent HHV. These NPE’s compare favorably to the most advanced industrial direct-fired systems. For example, a natural gas-fired GE MS7001-F has published HHV efficiencies of 31.1 percent simple cycle and 46.1 percent combined cycle (Gas Turbine World, 1990).
New Power Plant Concept for Moist Fuels, IVOSDIG
Authors: Hulkkonen S. , Raiko M. , Äijälä M.
Published: March 2015

Imatran Voima Oy (IVO) is developing an advanced gas turbine power plant process for wet fuels as peat, biomass, and lignite. The process consists of a steam injected gas turbine, an air blown gasifier and a pressurized fuel dryer. The dryer operates at steam atmosphere and is integrated to the process to produce injection steam for the gas turbine. The heat needed for drying is taken from the exhaust gases of the gas turbine. The process is patented and called IVOSDIG.
Optimal Measurements and Health Indices Selection for Gas Turbine Performance Status and Fault Diagnosis
Authors: Stamatis A. , Mathioudakis K. , Papailiou K.
Published: March 2015

In this paper, we present a method for defining the health estimation parameters and the measurements which must be used, when a monitoring system of an Engine has to be set-up. The particular engine layout, the available measuring instruments and the accuracy by which data can be collected are the factors taken into account. The particular health condition estimation factors, which have to be used, are defined as a function of this information and the desired depth of fault identification. A fast selection procedure based on the method of Singular Value Decomposition is presented. The uncertainty in the estimations is also derived, giving thus an additional element of information useful for decision making. The proposed method together with Adaptive Performance Modelling provides a self sufficient tool, which can be applied for setting up and subsequent exploitation of a health Monitoring Expert System. The advantage of the procedure is that it provides a frame of application, allowing quick implementation in a new engine of interest, other than the ones previously considered.
Digital Controller Improves Power and Flexibility of Gas Turbine Driven M1A1 Tank
Authors: Ericksen J. , Godere E. , Wright A.
Published: March 2015

This paper describes the design and development of a Digital Electronic Control Unit (DECU) that replaces the existing Analog Electronic Control Unit (AECU) on the M1A1 battle tank’s TEXTRON Lycoming AGT1500 gas turbine engine. This program marks the first application of a digital control on a vehicular gas turbine engine. The DECU preserves all functions of the AECU and is interchangeable, while allowing engine performance improvements, such as 20 percent fuel savings at idle. Diagnostic capabilities, using existing control sensors, were added to identify 90 percent of failed Line Replaceable Units. Controls strategies to achieve these results, such as adaptive routines, and some of the illustrative differences between Analog and Digital control implementations encountered in this application, are discussed.
Vibration Diagnostics by Expert Systems That Link to Machinery Databases
Authors: Hewitt James A. , Bosmans Ronald F.
Published: March 2015

An Expert System is a software program that simulates the thought process of experts. The addition of an expert system to a machinery monitoring system provides a diagnostic monitoring system that is easier to use and understand. This paper describes a system that automatically analyzes the data collected by an online machinery monitoring system. It examines the system architecture required to add intelligent diagnostic capabilities to the monitoring system as well as the data necessary for adequate diagnosis. An example of the system’s operation is also presented.
A Predictive NOx Monitoring System for Gas Turbines
Authors: Hung W. S. Y.
Published: March 2015

There is great interest in an alternative to the current rather expensive, high maintenance, weather sensitive, Continuous Emission Monitoring Systems (CEMS) or Continuous Emission Rate Monitoring Systems (CERMS) for stationary power sources. This is particularly relevant for smaller sources (<10 MW), as well as sites in remote areas and sites subject to extreme ambient conditions.

This paper describes the development of a predictive NOx monitoring system for industrial gas turbines. This type of system is currently being used as an alternative to in-stack CEMS or CERMS. This Predictive Emission Monitoring System (PEMS) utilizes a time-tested, proven mathematical model for NOx to verify the accuracy of a proven performance/emissions computer program which predicts NOx emissions from gas turbines based on measured ambient and turbine control parameters.

The technical background of this predictive NOx monitoring system and relevant experience are reviewed. The system design, including input and output, is described. A comparison of some technical issues between this predictive monitoring system and an actual typical in-stack NOx emission monitoring systems is also presented. A manual verification of the principle of this predictive system is reported.
The Mojave Cogeneration Project Unit 2
Authors: Redmond J. L. (Larry) , Marson Ezio
Published: March 2015

A cogeneration application of the CW251B10 industrial gas turbine is described in this paper. The gas turbine will generate electrical power and steam from a waste heat recovery boiler located downstream of the turbine exhaust. The steam generated by the boiler will be used to generate additional power in a Westinghouse condensing steam turbine. Steam will be extracted from the steam turbine for use in the plant and for injection into the gas turbine for NOx emission reduction. A description of the plant and components is included. Site performance tests results are presented and compared to the original predicted engine and plant performance.
Investigation of the Prediction of Losses in Radial Vaneless Diffusers
Authors: Dou Huashu
Published: March 2015

The non-dimensional width B and the inlet flow angle αi are the important parameters influencing the losses and the stability of radial vaneless diffusers. Their effects on diffuser losses are analyzed in this paper. The portions of the various flow losses change with the variation of non-dimensional width parameter B and flow angle αi. In a diffuser with small width B, the loss is primarily due to wall friction loss. In a diffuser with large B, the wall friction loss becomes a small part of the total loss, especially when αi is large. Comparison with experimental data shows that it is better to calculate the performance parameters of radial vaneless diffusers by using Dou’s method than by Senoo’s method in the design of centrifugal compressors. Senoo’s method is found to be only suitable for the conditions of small B values because it calculates simply the wall friction loss and the secondary flow loss and neglects diffusion loss.
A Software Environment for the Modelling, Simulation and Control of Industrial Gas Turbine Engines
Authors: Poole C. , Salsi A. G. , Bhinder F. S. , Kumar S.
Published: March 2015

This paper describes a computer program which has been developed to simulate industrial gas turbine engines to aid the design and application of fuel controllers. It explains the program structure and, as an example, gives the application of the program to the modelling of a simple two shaft industrial gas turbine engine. A brief discussion of the value of the implementation language, C++, is also given.
A New 1.7MW Industrial Gas Turbine: The Ruston Hurricane
Authors: Sanders A. T. , Tothill M. H. , Wood G. R.
Published: March 2015

The paper describes the design of a compact new 1.7MW (2300hp) single shaft industrial gas turbine and package, with high efficiency and exhaust temperature ideal for industrial congeneration applications.

These advantages are obtained with a high pressure ratio single stage centrifugal compressor, single high temperature combustor and two-stage axial flow turbine using only one row of cooled blades. The novel design features are described with the associated development testing. A typical installation is also described showing the potential for very high overall thermodynamic efficiency.
Measurements of Hot Combustor Turbulence Spectra
Authors: Moss R. W. , Oldfield M. L. G.
Published: March 2015

This paper presents measurements of turbulence spectra at the exit plane of aircraft turbine combustors running at atmospheric exit pressure. These measurements are important in providing realistic input conditions for both experimental measurements and CFD predictions of first stage turbine heat transfer.

A transient technique in which a pitot probe was only briefly exposed to the flow allowed uncooled, flush mounted sub-miniature pressure transducers to be used for measuring the turbulence spectra of combustor exhaust gases at temperatures up to 1500 K.

Three different burner configurations were tested at fuel : air ratios from 0 to 0.02. It was found that the combustion process makes little difference to the turbulence power spectrum at wavenumbers between 100 and 1200 m−1. The effect of using two fuels with different burning rates ( paraffin and diesel ) was also studied.

A brief description of the probe calibration is included. The response was found to be a function of both frequency and wavenumber.
Problems Associated With Wall Temperature Measurement and Prediction in Small Combustors
Authors: Odgers J. , Laganière E. , Kretschmer D.
Published: March 2015

This paper takes a look at some of the problems facing engineers who have to predict wall temperatures in small combustors. It is demonstrated that existing prediction techniques are not necessarily applicable, and that this is largely due to imprecise knowledge of the gas temperature within the recirculation, primary and early parts of the secondary zones. Additional errors may be incurred due to the relatively thick lip thickness. Overpenetration of the fuel spray can sometimes occur and, locally, this may even give rise to wall temperatures cooler than the inlet (cooling) air.
Lean Blowout in a Research Combustor at Simulated Low Pressures
Authors: Sturgess G. J. , Heneghan S. P. , Vangsness M. D. , Ballal D. R. , Lesmerises A. L.
Published: March 2015

A propane-fueled research combustor has been designed to represent the essential features of primary zones of combustors for aircraft gas turbine engines in an investigation of lean blowouts. The atmospheric pressure test facility being used for the investigation made it difficult to directly approach the maximum heat release condition of the research combustor. High combustor loadings were achieved through simulating the effects on chemical reaction rates of sub-atmospheric pressures by means of a nitrogen diluent technique. A calibration procedure is described, and correlated experimental lean blowout results are compared with well-stirred reactor calculations for the research combustor to confirm the efficacy of the calibration.
High-Temperature Gas Generator With Ceramic Components for Stationary Equipment Gas Turbine Unit
Authors: Shishov G. A. , Sudarev A. V. , Dubershtein V. N. , Tsurikov A. N.
Published: March 2015

The paper gives description of the systematic analysis algorythm for multifactor matrix of partial solutions, namely, aerodynamic, thermodynamic, strength, processing, design, operation, and other aspects of designing the assemblies and parts of the gas generator with ceramic components. Interrelations between structural ceramics thermophysical and strength parameters, joint techniques (ceramic–ceramic and ceramic–metal components) has been determined at an optimum selection of turbine and compressor types and characteristics.

The complex of processing, design, and operation factors influencing the design of the components and assemblies of the gas generator has been studied.
Advanced Ceramic Engine Technology for Gas Turbines
Authors: Carruthers W. D. , Smyth J. R.
Published: March 2015

The Advanced Turbine Technology Applications Project (ATTAP) is addressing critical technologies for the application of ceramics in gas turbine engines. These technologies include design methods, component development, component fabrication, and engine testing. Both analytical and experimental methods are being used to develop design methods for improving resistance to impact and contact damage. Component improvements are directed at a carbon-free combustor, durable regenerator seals, and an impact-resistant turbine stage design. Subcontractors are utilizing engineered experiments to develop consistent processes to produce high-quality ceramic turbine rotors and other components. These efforts are aimed at achieving satisfactory operation during durability tests at temperatures up to 2500F and 300 hours operation.
Heat Transfer Characteristics of Rotating Ceramic Regenerators: Numerical Solution Using a Hybrid Finite Difference/Laplace Transform Scheme
Authors: Kawasaki Keiji , Matsuhisa Tadaaki , Sakai Itsuro , Hijikata Kunio
Published: March 2015

A hybrid numerical method, combining finite differences with respect to space and a Laplace transform with respect to time, is proposed to determine the heat transfer in a rotary heat exchanger used as a rotating ceramic regenerator for automotive gas turbines. The temperature distributions of the core and of the working fluids are solved for given boundary and initial conditions of a rotary regenerator using this method. An advantage of the present method is that it can be applied when the core and the working fluids have dissimilar temperature distributions.

The temperature change in the ceramic honeycomb core was determined from start up to periodic steady state operation. The heat exchanger effectiveness was obtained for an extruded ceramic core used in automotive gas turbine applications.
Study of Ceramic Application in Heavy Duty Gas-Turbine Blades
Authors: Ikeda T. , Okuma H. , Okabe N.
Published: March 2015

To improve the efficiency of gas-turbines, their firing temperature has been greatly increased up to the 1300°C range due to the progress in heat resistant alloys and blade cooling techniques. This trend, however, seems to become weakened recently. Accordingly the ceramic alternative with much higher limits are becoming even more attractive, though some of the past studies have not shown optimistic prospects for the application.
Design and Performance of Advanced Blading for a High-Speed HP Compressor
Authors: Ginder R. B.
Published: March 2015

A set of advanced blading has been designed for a 5-stage high-speed research core compressor. The blade profiles were aerodynamically-tailored using a sophisticated quasi-3D S1-S2 flow calculation system which was developed at RAE Pyestock. This system involves iteration between blade-to-blade calculations using an inviscid-viscous code, and a streamline-curvature calculation for the pitchwise-averaged throughflow. The design and measured performance of the new compressor are compared with an initial conventionally-bladed 4-stage version. The new design achieved a peak level of poly tropic efficiency approaching 91%, a substantial improvement on the initial version, but showed a shortfall in pressure ratio compared with design intent. Post-test analyses based on measured performance data are used to give further insight into this result and indicate possible improvements in the design approach.
An Investigation in the Variance in Particle Surface Interactions and Their Effects in Gas Turbines
Authors: Hamed A. , Tabakoff W.
Published: March 2015

This work presents the results of a study conducted to investigate particle surface interaction characteristics and their effects on the particle dynamics and blade erosion in axial flow gas turbines. The particle restitution velocities measured experimentally using Laser Doppler Velocimetry in a special tunnel are analyzed using statistical methods. The resulting distribution functions of the rebounding particle velocities after surface impacts are introduced in the particle trajectory simulations through the turbine blade passages, using a methodology that combines particle dynamics computations in a probabilistic model. The presented results for the simulated ash particle dynamics demonstrate the effect of the experimentally measured variance in the particle restitution characteristics on the particle surface impacts, and the associated blade erosion in an axial flow turbine.
A Propulsion Perspective of the Next Generation Supersonic Transport
Authors: Feig P. D. , Gilkey S. C.
Published: March 2015

There is a growing, worldwide interest in a second generation supersonic transport aircraft. Air travel has tripled in the past 20 years to approximately 1000 billion revenue-passenger-miles per year. By the year 2010, air travel is anticipated to be 2 1/2 times that value, with long-range international travel the fastest growing segment. In order to become a reality, the second generation supersonic transport must be both environmentally acceptable and economically competitive with future subsonic aircraft.

Current research is now focused on addressing the major environmental issues of airport noise, engine emissions, and sonic boom. GE is studying a variety of engine and exhaust nozzle concepts and validating the emissions and acoustics technologies needed for this aircraft. In 1990, GE and P&W decided to work together to explore the feasibility of developing a second generation SST propulsion system. This paper provides an insight into our ongoing research and highlights the propulsion system’s influence on the viability of the second generation SST.
Propulsion Requirements for High Altitude Long Endurance Flight
Authors: Gallington Roger W.
Published: March 2015

This paper presents a set of general propulsion system performance requirements for high altitude long endurance flight. This flight objective places dramatically different values on fuel consumption, air consumption, system weight, and required heat rejection than the better understood range-payload objective. Some differences in overall vehicle design that suggest unusual propulsion systems are: (1) Optimum wing loadings for endurance at altitude are lower than acceptable for adequate wind penetration during descent and control during landing; (2) Compressing and cooling air at high altitudes requires large apparatus making specific air consumption very important; and (3) The lower specific power requirement and large fuel fractions make fuel consumption relatively more important than system weight. Based on the realistic expectations of aircraft aerodynamic performance and structural efficiency, the paper derives the correct propulsion system tradeoffs and extends these tradeoffs to include electrically-powered aircraft. A propulsion system designer can use the material presented here to guide the design of a high altitude long endurance propulsion system without active involvement of an airplane design team. The resulting propulsion design will be near-optimum.
Development of a Lubrication System for the T800-LHT-800 Turboshaft Engine
Authors: Douglas Laura M.
Published: March 2015

The T800-LHT-800 is a modern technology 1300 shp (975 kW) class turboshaft engine developed for the U.S. Army’s LH helicopter which has great potential for application in various civil air vehicles. As one of its significant features, the engine has a self-contained dry sump, pressure and temperature regulated, recirculating lubrication system. Contractually specified operational attitude and loss of oil requirements impose considerable complications on the design/development of the T800’s lubrication system.

Characteristically, lubrication systems provide cooling and lubrication to all bearings, gears, seal rotors, and working splines at all engine operating conditions. The T800-LHT-800 lubrication system must provide continuous lubrication for an engine operational attitude envelope range of 120 deg noseup, 90 deg nosedown, and 48 deg rolls in either direction. Development of the lubrication system attitude capabilities has been accomplished via testing on a lubrication simulator rig and a series of both development and qualification engine attitude tests. A formal engine attitude qualification test, which will demonstrate both military qualification test (QT) and civil (FAA) certification requirements, will be conducted in 1991.

Contractually required engine protection against loss of oil conditions lasting up to six min provided a significant design challenge for the T800 lubrication system and an emergency oil system was designed to meet this requirement. This emergency oil system was developed via multiple design iterations, bench testing on a lubrication simulator rig, and loss of oil development engine testing. As part of the qualification process, a formal qualification loss of oil engine test will be conducted in mid-1991 to verify this design capability.

This paper describes the basic T800 engine and discusses the lubrication system requirements. It emphasizes the design evolution of the main oil tank attitude capabilities, the emergency oil system, and the planned qualification/certification testing.
Liquid Cooled Turbocharged Propulsion System for HALE Application
Authors: Wilkinson R. E. , Benway R. B.
Published: March 2015

An unmanned air vehicle (UAV) capable of sustained flight in the upper limits of the tropopause is a relatively new technology which has seen increasing interest during the past decade. Mission lengths for High Altitude Long Endurance (HALE) applications are typically measured in days rather than hours with operating altitudes ranging from 50,000 to 100,000 feet. An Otto cycle propulsion system offers significant performance advantages over other cycles. This paper provides a technical assessment of a liquid cooled turbocharged, reciprocating engine concept capable of meeting the requirements for a HALE vehicle. A properly designed spark ignition engine with a two or three stage series turbocharger system utilizing state-of-the-art aerodynamic design can meet the challenges presented at these altitudes. Several records for long endurance and high altitude flight have already been set with this type of propulsion system. A comparison with other candidate engines will also be made. The ability to operate with low brake specific fuel consumption (BSFC) across a broad operating range will be identified. With sufficiently high exhaust gas temperatures, the addition of a power turbine for turbocompounding can further reduce the BSFC and brake specific air consumption (BSAC). A version of the turbocharged spark ignition engine is capable of providing high thermal efficiency with the least BSAC and minimum turbomachinery weight.