bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endurance Testing of Marine Gas Turbines for the Royal Navy
Authors: McCartney Clive , Hughes Robin D. 
Published: February 2015

Royal Naval policy since 1967 has been to employ gas turbines for major surface warship propulsion. In support of this policy, all new engines have been subject to endurance testing at DTEO Pyestock.
Marinised Tyne and Olympus aero engines were tested during the 1960s and 70s which confirmed their initial suitability for RN service and uprated performance. Lessons learnt in formulating the test process were applied to the Spey SMIA engine programme in 1982. Further refinements, following comparison of sea operating experience with test bed results were applied to the 3000 hour endurance trial of the 18 MW Spey SMIC engine, which completed in 1993.
The current testing at Pyestock is of the 21.6 MW Intercooled Recuperated (1CR) WR21 engine, presently under development for the USN in cooperation with the RN. The endurance trials being planned will require a further change in emphasis in order to address the unique operating regimes of an 1CR engine.
The paper describes the evolution of endurance testing techniques, highlighting the particular requirements for complex cycle engines and discusses the opportunities that arose for piggyback trials during typical endurance testing regimes.
Partial Regenerative Steam Injected Gas Turbine
Authors: Uji Shigekazu 
Published: February 2015

Steam injection has been employed in gas turbines for over twenty-five years for power increase (more than 50% on some gas turbines) and efficiency improvements (more than 20%). For further improvement of efficiency on steam injected gas turbine, Partial Regenerative Steam Injected Gas Turbine was studied.
Cycle analysis was carried out for the evaluation of efficiency among three systems, Steam Injected Gas Turbine, Regenerative Steam Injected Gas Turbine and Partial Regenerative Steam Injected Gas Turbine. Results of the analysis show that Partial Regenerative Steam Injected Gas Turbine can realize higher efficiency than other two systems.
In addition to the cycle analysis, the effect of applying the concept of Partial Regenerative Steam Injected Gas Turbine to the actual engine Allison gas turbine model 501-KH was evaluated. And the effect of integrating compressor inter-cooling process in Partial Regenerative Steam Injected Gas Turbine was also evaluated.
A Three-Dimensional Shock Loss Model Applied to an Aft-Swept, Transonic Compressor Rotor
Authors: Puterbaugh Steven L. , Copenhaver William W. , Hah Chunill , Wennerstrom Arthur J. 
Published: February 2015

An analysis of the effectiveness of a three-dimensional shock loss model used in transonic compressor rotor design is presented. The model was used during the design of an aft-swept, transonic compressor rotor. The demonstrated performance of the swept rotor, in combination with numerical results, is used to determine the strengths and weaknesses of the model. The numerical results were obtained from a fully three-dimensional Navier-Stokes solver. The shock loss model was developed to account for the benefit gained with three-dimensional shock sweep. Comparisons with the experimental and numerical results demonstrated that shock loss reductions predicted by the model due to the swept shock induced by the swept leading edge of the rotor were exceeded. However, near the tip the loss model under-predicts the loss because the shock geometry assumed by the model remains swept in this region while the numerical results show a more normal shock orientation.
The design methods and the demonstrated performance of the swept rotor is also presented. Comparisons are made between the design intent and measured performance parameters. The aft-swept rotor was designed using an inviscid axisymmetric streamline curvature design system utilizing arbitrary airfoil blading geometry. The design goal specific flow rate was 214.7 kg/sec/m2 (43.98 lbm/sec/ft2), the design pressure ratio goal was 2.042, and the predicted design point efficiency was 94.0. The rotor tip sped was 457.2 m/sec (1500 ft/sec). The design flow rate was achieved while the pressure ratio fell short by 0.07. Efficiency was 3 points below prediction, though at a very high 91 percent. At this operating condition the stall margin was 11 percent.
Progress on the European Gas Turbine Program: AGATA
Authors: Gabrielsson Rolf , Holmqvist Göran 
Published: February 2015

The four-year European Gas Turbine Program “AGATA” was started in Jan 1993 with the objective to develop three critical components aimed at a 60 kW turbogenerator in an hybrid electric vehicle — a catalytic combustor, a radial turbine wheel and a static heat exchanger. The AGATA partners represent car manufacturers as well as companies and research institutes in the turbine, catalyst and ceramic material fields in both France and Sweden.
This paper outlines the main results of the AGATA project for the first three year period. During the third year of the program, the experimental verification of the components has started. A high pressure/temperature test rig for the combustor and the heat exchanger tests has been built and is now being commissioned. A high temperature turbine spin rig will be ready late 1995.
The turbine wheel design is completed and ceramic Si3N4 spin discs have been manufactured by injection moulding and Hot Isostatic Pressing (HIP). A straight blade design has been selected and FEM calculations have indicated that stress levels which occur during a cold start are below 300 MPa.
The catalytic combustor final design for full scale testing has been defined. Due to the high operating temperature, 1350°C, catalyst pilot tests have included ageing, activity and strength tests. Based on these tests, substrate and active materials have been selected. Initial full scale tests including LDV measurements in the premix duct will start late 1995.
The heat exchanger design has also been defined. This is based on a high efficiency plate recuperator design. One critical item is the ceramic thermoplastic extrusion manufacturing method for the extremely thin exchanger plates another is the bonding technique: ceramic to ceramic and ceramic to metal. Significant progress on these two items has been achieved. The manufacturing of quarter scale prototypes is now in process.
High Pressure Test Results of a Catalytic Combustor for Gas Turbine
Authors: Fujii T. , Ozawa Y. , Kikumoto S. , Sato M. , Yuasa Y. , Inoue H. 
Published: February 2015

Recently, use of gas turbine systems such as combined cycle and cogeneration systems has gradually increased in the world. But even when a clean fuel such as LNG (liquefied natural gas) is used, thermal NOx is generated in the high temperature gas turbine combustion process. The NOx emission from gas turbines is controlled through selective catalytic reduction processes (SCR) in the Japanese electric industry.
If catalytic combustion could be applied to the combustor of the gas turbine, it is expected to lower NOx emission more economically. Under such high temperature and high pressure conditions as in the gas turbine, however, the durability of the catalyst is still insufficient. So it prevents the realization of a high temperature catalytic combustor.
To overcome this difficulty, a catalytic combustor combined with premixed combustion for a 1300°C class gas turbine was developed. In this method, catalyst temperature is kept below 1000°C and a lean premixed gas is injected into the catalytic combustion gas. As a result, the load on the catalyst is reduced and it is possible to prevent the catalyst deactivation.
After a preliminary atmospheric test, the design of the combustor was modified and a high pressure combustion test was conducted. As a result, it was confirmed that NOx emission was below 10ppm (at 16% O2) at a combustor outlet gas temperature of 1300°C and that the combustion efficiency was almost 100%.
This paper presents the design features and test results of the combustor.
Experimental Investigation of the Liquid Fuel Evaporation in a Premix Duct for Lean Premixed and Prevaporized Combustion
Authors: Brandt Michael , Gugel Kay O. , Hassa Christoph 
Published: February 2015

Liquid fuel evaporation was investigated in a premix duct, operating at conditions expected for lean premixed and prevaporized combustion. Results from a flat prefilming airblast atomizer are presented. Kerosine Jet A was used in all experiments. Air pressure, air temperature and liquid fuel flow rate were varied separately, their relative influences on atomization, evaporation and fuel dispersion are discussed.
The results show, that at pressures up to 15 bars and temperatures up to 850 K, nearly complete evaporation of the fuel was achieved, without autoignition of the fuel. For the configuration tested, the fuel distributions of the liquid and evaporated fuel sbow very little differences in their dispersion characteristics and were not much affected by a variation of the operating conditions.
On Calculation and Optimization of Energy Systems
Authors: Ortmann Peter , Gyarmathy George 
Published: February 2015

Most modern plants offer a variety of control methods which can be used one-by-one or in combination. For instance, in case of CC plants, control methods can comprise e. g. fuel control, adjustable compressor guide vanes and various feed preheat options. For the actual part-load operation the knowledge of optimum combinations is of great interest.
A computer code based on standard mathematical optimization tools for large non-linear systems of equations has been developed and tested on various gas-turbine and CC power plant configurations. The code can be employed to plants of almost any level of complexity and to any particular plant layout.
The range of control action is always limited by technological constraints imposed by mechanical, thermal, chemical or other limits and prescribed by the equipment manufacturer. The optimization code has been devised to respect an arbitrary number of such conditions as e. g. flue gas temperature, steam turbine moisture, gas turbine exit temperature and the like.
Such limits and operating instructions concerning the observance of certain parameter ranges (e. g. limits prescribed for sake of life-cycle extension) can be introduced into the optimization procedure.
Failure Analysis of a Burner Component
Authors: Saunders Kenneth L. , Copley Brian P. 
Published: February 2015

The cogeneration facility of interest contains four identical cogeneration units which produce about one half million Kg per hour of steam for an adjacent refinery and 385 megawatts of electricity. To supplement the production of steam, burners are used to heat the gas turbine exhaust. These burners incorporate shields to deflect exhaust gas flow around the flame base.
In an effort to improve burner emissions of the units, the burner shield design was modified. This alteration resulted in gross deformation of the shields which interfered with combustion. A failure analysis of these components was conducted to ascertain the root cause of the observed behavior. Loads were estimated based upon operational conditions and material properties were obtained from the open literature. An evaluation was conducted to determine the temperature distribution first. This temperature distribution was then coupled with mechanical loading to obtain total operational stress levels. The stress levels at the observed temperatures clearly placed the material in the high strain rate (creep) region. The computed stress distribution confirmed the observed failure configuration.
A new design was proposed to eliminate this failure mechanism. Detailed evaluations revealed that the new design, while a significant improvement, still operated near the creep region for the material.
Modeling Support Effects: Finite Element and Experimental Modal Methods
Authors: Buckles Jonathan R. , Rouch Keith E. , Baker John R. 
Published: February 2015

The effects of support/foundation dynamics are often significant in high speed turbomachinery, and can affect the stability and response to unbalance. In some cases additional critical speeds are introduced, related to resonances in the foundation or interaction with rotor resonances of foundation resonances.
This paper reviews several methods for representing these effects, including (1) reduced matrices from finite element substructures (ANSYS, for example), (2) matrices generated from modal data, and (3) direct use of experimental transfer functions. These methods are implemented in a finite element rotor program in a PC-DOS environment.
The application of the methods to two laboratory rotor configurations described and results presented. Situations with a foundation resonance above and near the rotor critical are included. The importance of including coupling effects between supports is shown.
Torque and Power Loss in a Cylindrical Fluid-Lubricated Bearing/Rotor System
Authors: Goldman Paul , Petchenev Alex , Bently Donald E. , Muszynska Agnes 
Published: February 2015

The paper contains the study of the lubricant fluid forces applied to the journal in a cylindrical, externally-pressurized bearing. The analytical expressions take into account the appearance of fluid cavitation at high eccentricity level.
The obtained expressions for fluid forces and torque are used for numerical simulation of a simple, one-mode rotor system. The system exhibits typical fluid whirl/whip instability which results in high fluid resistance torque values. The latter is considered as one of the causes of turbomachinery efficiency deterioration due to fluid-induced instabilities.
This paper is a continuation of the study undertaken by Bently et al. (1985), Muszynska (1986), and Petchenev et al. (1995).
RAM - Performance of Modern Gas Turbines
Authors: von Rappard Axel W. , Neuhoff Heinz G. , Della Villa Salvatore A. 
Published: February 2015

Power and heat rate, and exhaust gas and noise emissions are commonly used to evaluate the performance of power generation equipment. Recently, reliability, availability and maintainability (RAM) are being widely adopted as more significant evaluation criteria for gas turbine power plants. All the criteria are used to evaluate new equipment and the measurements on previous installations are the basis for expected values. What differentiates RAM from the other three criteria is the duration of the measurements. Collecting and processing of RAM data is different since it needs to be collected during normal operation of the plant and over a long period of time. This means it is a coordinated effort of both partners; the customers and the manufacturers.
This paper provides a summary of results over a period of four years with a review of the data and conclusions concerning the actual operation. It shows that gas turbine plants can be operated with high reliability and availability requirements. Outages can be reduced in both frequency and length, if the service management is based on the shared information of a worldwide RAM field data collection. A coordinated communication line is a prerequisite for sharing this information. The exchange of information is also mandatory if short reaction time for improvements is required. The planning for the implementation of the communication tools is presented in detail in terms of a ‘road map’ of this program.
Study of Three-Dimensional Viscous Flow Field in Axial-Flow Fan
Authors: Su Moming , Gu Chuan-gang , Miao Yong-miao 
Published: February 2015

The complex three-dimensional flow field in an axial-flow impeller incorporating high-Reynolds-number k-ε turbulence model is studied in this paper. The fully three-dimensional Reynolds averaged Navier-Stokes equations are solved. A computational procedure has been developed for predicting three-dimensional incompressible separated turbulent flows in the impeller. The SIMPLE-like algorithm is used. Convective terms are approximated with higher-order upstream-weighted approximations and a TVD-type MUSCL scheme. Physical covariant velocity components are selected as dependent solving variables. The non-orthogonal boundary-fitted coordinate system and collocated grid arrangement are also employed. Rhie and Chow’s momentum interpolation method is adopted to eliminate the non-physical pressure and velocity oscillations. Periodic boundary condition and moving wall boundary condition are considered to simulate truthfully the turbulent flow field in impeller.
Two types of axial-flow impellers are computed. The first one is designed by ordinary method and the other is a improved design that has been considered with eliminating flow separation and viscous vortex in the first design. The computed results show that the fully tree-dimensional turbulent flows computation can efficiently predict three-dimensional separated flows and viscous vortex in axial-flow impeller and vaneless clearance. Using the program, a designer can improve passage geometric design to enhance the performance of the fan.
Surface Optimisation by Engineering the Stress and Roughness
Authors: O’Hara Peter 
Published: February 2015

Performance of turbine components can significantly be affected by surface/subsurface characteristics. Techniques applied today and being developed further entail introducing into a components surface a residual compressive stress of predictable magnitude and depth followed by superfinishing to improve the surface finish.
The effect will be to lower the mean stress which will increase component life and fatigue strength or enable higher loads through present designs; develop a damage tolerant layer capable of withstanding corrosion pitting or strike damage while in service and produce a final roughness capable of improving flow characteristics on turbine blades/buckets.
The processes to achieve the above include Controlled Shot Peening and Superfinishing. In combination, an optimised surface condition will result.
Application of Transient and Dynamic Simulations to the U.S. Army T55-L-712 Helicopter Engine
Authors: Savelle S. A. , Garrard G. D. 
Published: February 2015

The T55-L-712 turboshaft engine, used in the U.S. Army CH-47D Chinook helicopter, has been simulated using version 3.0 of the Advanced Turbine Engine Simulation Technique (ATEST) and version 1.0 of the Aerodynamic Turbine Engine Code (ATEC). The models simulate transient and dynamic engine operation from idle to maximum power and run on an IBM-compatible personal computer. ATEST is a modular one-dimensional component-level transient turbine engine simulation. The simulation is tailored to a specific engine using engine-specific component maps and an engine-specific supervisory subroutine that defines component interrelationships. ATEC is a one-dimensional, time-dependent, dynamic turbine engine simulation. ATEC simulates the operation of a gas turbine by solving the one-dimensional, time dependent Euler equations with turbomachinery source terms. The simulation uses elemental control volumes at the sub-component level (e.g. compressor stage).
The paper discusses how limited information from a variety of sources was adapted for use in the T55 simulations and how commonality between the models allowed reuse of the same material. The first application of a new turbine engine model, ATEC, to a specific engine is also discussed. Calibration and operational verification of the simulations will be discussed, along with the status of the simulations.
Prediction of the Three-Dimensional Reacting Two-Phase Flow Within a Jet-Stabilized Combustor
Authors: Kurreck M. , Willmann M. , Wittig S. 
Published: February 2015

Numerical calculations of the two-phase flow in an experimentally well investigated research combustor are presented. The comparison between measurements and calculations demonstrates the possibilities of the state-of-the-art Euler/Lagrange method for calculating two-phase flows, when applied to a complex reacting liquid fueled combustor. The governing equations for gaseous and liquid phase are presented, with special emphasis on the control of the coupling process between the two phases. The employed relaxation method together with a protocol of convergence show a suitable way to achieve a fast and accurate solution for the strongly coupled two-phase flow under investigation.
Furthermore methods are presented to simulate the stochastic behaviour of the atomization process that appears due to the use of an airblast atomizer. In addition to the numerical methods, experimental techniques are presented, which are used to achieve detailed information about droplet starting conditions.
Mixing of Multiple Jets With a Confined Subsonic Crossflow in a Cylindrical Duct
Authors: Holdeman James D. , Liscinsky David S. , Samuelsen G. Scott , Oechsle Victor L. , Smith Clifford E. 
Published: February 2015

This paper summarizes NASA-supported experimental and computational results on the mixing of a row of jets with a confined subsonic crossflow in a cylindrical duct. The studies from which these results were excerpted investigated flow and geometric variations typical of the complex 3-D flowfield in the combustion chambers in gas turbine engines.
The principal observations were that the momentum-flux ratio and the number of orifices were significant variables. Jet penetration was critical, and jet penetration decreased as either the number of orifices increased or the momentum-flux ratio decreased. It also appeared that jet penetration remained similar with variations in orifice size, shape, spacing, and momentum-flux ratio when the number of orifices was proportional to the square-root of the momentum-flux ratio. In the cylindrical geometry, planar variances are very sensitive to events in the near-wall region, so planar averages must be considered in context with the distributions.
The mass-flow ratios and orifices investigated were often very large (mass-flow ratio >1 and ratio of orifice area-to-mainstream cross-sectional area up to 0.5), and the axial planes of interest were sometimes near the orifice trailing edge. Three-dimensional flow was a key part of efficient mixing and was observed for all configurations. The results shown also seem to indicate that non-reacting dimensionless scalar profiles can emulate the reacting flow equivalence ratio distribution reasonably well. The results cited suggest that further study may not necessarily lead to a universal “rule of thumb” for mixer design for lowest emissions, because optimization will likely require an assessment for a specific application.
Evaluation of a New Design Concept for a Ceramic Flame Tube Under Engine Conditions
Authors: Münz S. , Schulz A. , Wittig S. 
Published: February 2015

At the Institut für Thermische Strömungsmaschinen in Karlsruhe new design concepts for thermally high-loaded ceramic gas turbine components were developed. The present concept is based on a load-oriented segmentation in combination with a flexible suspension and thermal insulation of the ceramic structure. The concept was applied to a flame tube for a small gas turbine. In order to ensure real operating conditions, a Klöckner Humboldt Deutz T216 type gas turbine was used as test bed for the ceramic combustor.
The paper gives a description of the combustor and the test rig. Furthermore, experimental results of the engine tests with special emphasis on the liner wall temperature distribution for various steady and transient operating conditions are presented. A major result of the tests is that the design concept proved to be reliable under real engine conditions. After more than 100 hours no failure of the ceramic parts occured. In order to determine the thermal load of the ceramic flame tube under real conditions, the experimental investigations are supported by numerical calculations.