bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Code for Thermal Analysis of STIG Turbines
Authors: Bartolini Carlo M. , Salvi Danilo , Pennacchioli Marcello 
Published: February 2015

A computer model to evaluate the off-design performance of steam injection gas turbines (STIG) has been developed; the code utilizes turbine and compressor curves, and requires only one operation point as further input parameter. The global thermal analysis has been performed by means of the iterative solution of a non-linear equations system.
The model is based on the following hypothesis: air convection/film cooling process and turbine choking condition.
The prediction of air cooling flow has been correlated to the air temperature, function of the compressor efficiency and the bleed point pressure and to the gas temperature, directly related to the work output. The thermal exchange between blades and hot gas has been computed by means of a model proposed in literature.
The code is a handy tool to predict the off-design performance of STIG plants, also it can simulate the analysis of existing plants in order to evaluate the feasibility of some implementations.
An interesting analysis of the performance of a real STIG plant has been carried out and the comparison between the calculated and the experimental curves validates the computational procedure.
LM-2500 First Stage Filtration Upgrades
Authors: Johnson Steven R. , Thomas David A. 
Published: February 2015

This paper addresses problems and solutions associated with the first stage inlet air treatment systems provided with six General Electric (GE) LM-2500 PE aeroderivative gas turbines used in a Combined Cycle Cogeneration application. The LM-2500’s are sited adjacent to gypsum wallboard plants, which serve as the Cogeneration hosts.
Problems associated with the inlet air treatment systems were noted soon after start-up of the LM-2500 engines in June 1992 and February 1993. Poor performance of the air treatment system appeared to contribute to premature failures in the Gas Turbine hot sections. Heavy particulate loading due to the surrounding gypsum environment was identified as the root cause of the problems affecting the first and second filtration stages and the evaporative cooling stage of the engine inlet air systems.
Following air sampling tests, a number of modifications and upgrades were studied to improve the performance of the inlet air treatment. An engine inlet at each site was modified with a bag filter system for the first stage filtration. The performance of the modified inlets was then monitored and compared to the remaining units. After the successful performance of the modified inlets during the second and third quarters of 1994, the remaining LM-2500 engine inlets were subsequently modified in October 1994.
Numerical Transonic Flow Field Predictions for NASA Compressor Rotor 37
Authors: Dalbert Peter , Wiss Donald H. 
Published: February 2015

Flow field calculations of the NASA transonic axial compressor Rotor 37 are presented. These were obtained by the two commercially available 3D Navier Stokes-codes BTOB3D and TASCflow using different turbulence models, i.e. Baldwin-Lomax and k-ε. Some of the results were submitted to the CFD code assessment exercise organized in 1994 by the Turbomachinery Committee of the ASME, where a number of “blind” CFD predictions were compared against previously unknown experimental data taken at the NASA Lewis Research Center.
The objective of these calculations was to use the codes in the same way as they are generally used by experienced engineers for standard industrial design tasks. Thus, the effort involved in grid generation, flow simulation runs and postprocessing was subject to the usual limitations in computer resources as well as a stringent observation of cost-effectiveness (manpower and time available).
With both codes, two sets of calculations were carried out: BTOB3D with two different tip clearances and TASCflow with a uniform and a spanwise varying outlet static pressure. Generally, the results of both codes show good agreement with respect to the measured overall performance characteristics and averaged spanwise distributions. In particular, the TASCflow solutions display high prediction accuracy in some local details of the flow field while in the BTOB3D code, boundary effects seem to mix out the flow significantly.
The solution strategies employed as well as the reasons for certain discrepancies between computations and measurements are discussed.
Shroud Influence on Gas Turbine Airblast Atomizer Swirler Flowfields
Authors: Micklow Gerald J. , Shivaraman Karthikeyan , Cho Insoo 
Published: February 2015

The performance of high shear airblast fuel injectors for advanced gas turbine combustors is highly dependent on the design of the swirl vanes. The vanes may be of the straight or curved type. Curved vanes usually exhibit lower losses but straight vanes are also used due to lower cost and ease of manufacture. These type of vanes often operate under highly stalled conditions with high total pressure loss and a highly non-uniform exit velocity profile. This may produce poor fuel atomization with a non-uniform combustor fuel distribution resulting in lowered combustor efficiency and increased pollutant emissions.
Constant turning curved vanes can also be easily manufactured. Properly designed vanes result in a greatly reduced total pressure loss. The exit velocity distribution is more uniform and higher in magnitude which can result in improved fuel atomization and distribution in the combustor. Further, the presence of a shroud is seen to have a major effect on the downstream flowfield.
The present study compares standard helical flat vane performance with a low loss curved vane designed by the author for idle, and cruise conditions both with and without a shroud. The results from a three dimensional viscous numerical flow simulation show the curved swirl vane to be clearly superior to the standard flat helical swirl vane. The curved vane has a much lower total pressure loss with a more uniform exit velocity profile. This may result in improved combustor and engine performance and reduced pollutant emissions.
The effect of the shroud was seen to reduce the size of the stall cell found in the vane passage for the helical vane. This resulted in a decrease in the magnitude of the axial velocity component in the outer vane passage and a decrease in the circumferential velocity component. This may result in a decrease in the swirl number. For the curved vane however, an increase in the magnitude of all velocity components was found which will result in a higher swirl number and better nozzle performance.
Unsteady Pressure Measurement in a High Temperature Environment Using Water Cooled Fast Response Pressure Transducers
Authors: Ferguson D. G. , Ivey P. C. 
Published: February 2015

Measurement of unsteady pressure is a requirement in many proposed aero-engine active control systems. In the high temperature environment associated with the engine, thermally unprotected transducers may not measure accurately or even survive. This paper reports an examination of two water cooled, commercially available unsteady pressure transducers, which assesses the ability of the transducer to accurately measure unsteady pressure when mounted in a water cooling adapter and the effectiveness of the thermal protection at high temperatures.
Mounting the transducer in a cooling adapter was shown to have no adverse effect upon its ability to measure dynamic pressure. Deliberately recessing the adapter back from the flow provided the most stable and predictable output at all flow conditions tested. Thermal protection allowed the transducer to survive at flow temperatures of up to 500°C with a potential to survive at higher temperatures. No reduction in performance is shown at elevated temperatures relative to performance at ambient conditions.
Gas Temperature Measurement in the Hot Section of Turbine Engines
Authors: Tregay George W. , Calabrese Paul R. , Finney Mark J. , Stukey Kevin B. 
Published: February 2015

An optical sensor system extends gas temperature measurement capability in turbine engines beyond the present generation of sensor hardware for production engines. The sensing element incorporates a thermally emissive insert to generate an optical signal proportional to the gas temperature at the tip of the probe. The use of a sapphire lightguide allows operation above the melting point of nickel based alloys.
Sensor development for aircraft turbines has included flight hardware for use on the Fiber Optic Control System Integration (FOCSI) Program sponsored by NASA Lewis Research Center. The optical probe harness measured exhaust gas temperatures in a General Electric F404 engine. Signals from four probes were optically combined at a single detector assembly to determine the average gas temperature. A comparison of optical and thermocouple temperature measurements was conducted during a preflight engine test.
The durability of the probe design has been evaluated in an electric-utility operated gas turbine under the sponsorship of the Electric Power Research Institute. The temperature probe was installed between the first stage rotor and second stage nozzle on a General Electric MS 7001B turbine at Houston Lighting and Power Company. Two probes have been used in the field test and they have a combined total of 4660 hours of operation near 1600°F and 330 starts.
Flow Analysis of High Pressure Catalytic Combustor for Gas Turbine
Authors: Tsujikawa Y. , Fujii S. , Sadamori H. , Ito S. , Katsura S. 
Published: February 2015

The objective of this paper is modeling the mechanism of high temperature catalytic oxidation of natural gas, or methane. The model is two-dimensional steady-state, and includes axial and radial convection and diffusion of mass, momentum and energy, as well as homogeneous (gas phase) and heterogeneous (gas-surface) single step irreversible chemical reactions within a catalyst channel.
Experimental investigations were also made of natural gas, or methane combustion in the presence of Mn-substituted hexaaluminate catalysts. Axial profiles of catalyst wall temperature, and gas temperature and gas composition for a range of gas turbine combustor operating conditions have been obtained for comparison with and development of a computer model of catalytic combustion.
Numerical calculation results for low pressure agree well with experimental data. The calculations have been extended for high pressure (10 atms) operating conditions of gas turbine.
Certification of Gas Turbine Propulsion Units for High Speed Light Craft
Authors: Waldhelm Chris , Bertsch Jim 
Published: February 2015

The drive to produce lighter, faster vessels has been increasing the market interest in marine gas turbine propulsion systems. Classification Rules for propulsion systems in vessels require certification. Classification Rules cover many aspects of design philosophies. For new, high speed and light craft designs, gas turbine power is being optimized to economically blend higher vessel speeds, lower operating costs, and improved payloads. As part of this process, a concurrent design effort involving class societies is highly recommended to speed certification and increase the project’s experience pool.
Classification Societies, as independent third parties, issue standards (rules) for safe design, construction, and operation of ships. Certification is used to document compliance with the standards or rules. The certification process is usually based on design reviews and witnessing of manufacturing and testing.
Recently, a project at Solar Turbines Incorporated required a pair of 5 MW marine gas turbines propulsion units to be certified by Det Norske Veritas Classification AS. The gas turbines drive waterjets for a 45 meter, 332 passenger, 47 knot vessel designed and manufactured by FBM Marine Limited in the United Kingdom.
The Application of Thin Film Gauges on Flexible Plastic Substrates to the Gas Turbine Situation
Authors: Guo S. M. , Spencer M. C. , Lock G. D. , Jones T. V. , Harvey N. W. 
Published: February 2015

Thin film heat transfer gauges have been instrumented onto flexible plastic substrates which can be adhesively bonded to plastic or metal models. These new gauges employ standard analysis techniques to yield the heat flux to the model surface and have significant advantages over gauges fired onto machinable glass or those used with metal models coated with enamel. The main advantage is that the construction of the gauges is predictable and uniform, and thus calibration for thickness and geometric properties is not required.
The new gauges have been used to measure the heat transfer to an annular turbine nozzle guide vane in the Oxford University Cold Heat Transfer Tunnel. Engine-representative Mach and Reynolds numbers were employed and the free-stream turbulence intensity at NGV inlet was 13%.
The vanes were either precooled or preheated to create a range of different thermal boundary conditions. The gauges were mounted on both perspex and aluminium NGVs and the heat transfer coefficient was obtained from the surface temperature history using either a single layer analysis (for perspex) or double layer (for aluminium) analysis. The surface temperature and heat transfer levels were also measured using rough and polished liquid crystals under similar conditions. The measurements have been compared with computational predictions.
Evaluation of High Pressure Turbine Blade Coatings on an LM2500 Rainbow Rotor
Authors: Nagaraj B. , Katz G. , Maricocchi A. F. , Rosenzweig M. 
Published: February 2015

Two LM2500 rainbow rotors with repaired stage 1 and stage 2 high pressure turbine blades are being assembled for marine propulsion service evaluation by the US Navy. The blades have seen between 5,000 and 15,000 hours of service in the Navy’s Fleets. A number of corrosion resistant coatings including plasma sprayed CoCrAlHf (bill of material), composite plated CoCrAlHf, platinum aluminide, aluminum silicide, and physical vapor deposited yttria stabilized zirconia thermal barrier coating (PVD TBC) will be evaluated in the rainbow rotor. This paper will discuss the advantages and microstructures of the various coatings.
Composite plated CoCrAlHf, and PVD TBCs were recently service evaluated in an industrial LM2500 rainbow rotor for 10,500 hours. Both these coatings performed well, although the PVD TBC had local spallation at the leading edge. This paper will review the details of performance of these two coatings in the industrial LM2500 application.
The Design and Initial Development of a Combustion System for the WR-21 Intercooled Recuperated Gas Turbine
Authors: North Richard P. , Dawson Roger E. 
Published: February 2015

This paper presents the design and initial development of a conventional combustion system to meet the specific requirements of an Intercooled Recuperated (ICR) Gas Turbine for Marine Propulsion use.
The ICR cycle offers considerable benefit in terms of fuel consumption over a wide power range, however, it presents the combustion designer with unique requirements including, but not limited to, air-to-fuel ratio (AFR) operating range, combustor inlet temperature range and combustion aerodynamics, whilst achieving acceptable combustion parameters such as ignition envelope, exit temperature traverse, smoke and emissions, component durability and integrity. The design and development of solutions to these challenges considered and chosen for the WR-21 are discussed, and results of early rig and engine testing outlined.
Effect of Machining and Shot Peening on the Residual Stresses of Superalloy Turbine Discs
Authors: Taricco Federica 
Published: February 2015

It is well known that the field of residual stresses in the surface layer of a component greatly influences its fatigue behavior. The distribution of stresses is created by processes like welding, machining, thermal treatments.
The object of the present study was to correlate the effect of operations like turning, broaching and shot peening with the residual stresses of a highly–stressed flight safety component like a turbine disc made in Inconel 718 superalloy.
The residual stress distributions were measured with newly installed x–ray diffraction equipment, in which real engine components can be tested.
Different machining parameters and tools were used, and other factors like deformations during processing and thermal conditions of the disc in service were taken into account.
The final aim of the activity was to perform a manufacturing cycle which can minimize production costs and, at the same time, guarantee the highest possible quality level required in such a critical component.
Design and Experimental Investigation of a Mixed Flow Supersonic Compressor Stage
Authors: Elmendorf Wolfgang , Kurz Harald , Gallus Heinz E. 
Published: February 2015

Highly loaded transonic and supersonic compressors appear capable of meeting the future demands of small gas turbines and jet engines. Particularly mixed flow compressors, taking advantage of the increasing circumferential blade speed between rotor inlet and exit, represent a good compromise with regard to high pressure ratio and mass flow on the one hand, and favorable performance characteristics and efficiency on the other.
However, operating a supersonic rotor as part of a stage involves a stator characterized by high turning angles, supersonic inlet conditions and a strong flow deceleration. In fact, the stator can be identified as the critical component regarding overall stage performance. Based on experimentally determined rotor exit flow conditions, the first part of this paper describes the design of a tandem stator with a strong shock in the stator entrance region, followed by subsonic flow turning and diffusion.
The main thrust of this paper is to present the analytical results obtained in connection with the experimental investigation of the complete stage at design and off-design conditions. Rotor and stator flow as well as the overall stage performance are discussed in detail. The concept of the tandem stator proves to be suitable for managing the extremely high aerodynamic loading in the Stator. Experimental results reveal the design goals to be met in general.
Ceramic Stationary Gas Turbine Development Program: Design and Life Assessment of Ceramic Components
Authors: Norton Paul F. , Frey Gary A. , Bagheri Hamid , Flerstein Aaron , Twardochleb Chris , Jimenez Oscar , Saith Arun 
Published: February 2015

A program is being performed under the sponsorship of the United States Department of Energy, Office of Industrial Technology, to improve the performance of stationary gas turbines in cogeneration through the selective replacement of hot section components with ceramic parts.
It is envisioned that the successful demonstration of ceramic gas turbine technology, and the systematic incorporation of ceramics in existing and future gas turbines will enable more efficient engine operation, resulting in significant fuel savings, increased output power, and reduced emissions.
The engine selected for the program, the Centaur 50 (formerly named Centaur ‘H’) will be retrofitted with first stage ceramic blades, first stage ceramic nozzles, and a ceramic combustor liner. The engine hot section is being redesigned to adapt the ceramic parts to the existing metallic support structure.
The program currently in Phase II focuses on detailed engine and component design, ceramic component fabrication, ceramic component testing, establishment of a long term materials property database, and the development and application of supporting technologies in the areas of life prediction and non-destructive evaluation. This paper outlines the design activities associated with the introduction of a ceramic first stage nozzle and two configurations of ceramic first stage turbine blade. In addition, probabilistic life assessment of the ceramic parts for major failure modes (fast fracture, slow crack growth and where relevant, creep and oxidation) will be discussed.
Parametric Modelling of Exhaust Gas Emission From Natural Gas Fired Gas Turbines
Authors: Bakken L. E. , Skogly L. 
Published: February 2015

Increased focus on air pollution from gas turbines in the Norwegian sector of the North Sea has resulted in taxes on CO2. Statements made by the Norwegian authorities imply regulations and/or taxes on NOx emissions in the near future. The existing CO2-tax of NOK 0.82 /Sm3 (US Dollars 0.12/Sm3) and possible future tax on NOx are analysed mainly with respect to operating and maintenance costs for the gas turbine. Depending on actual tax levels, the machine should preferably be operated on full load/optimum thermal efficiency or part load to reduce specific exhaust emissions.
Based on field measurements, exhaust emissions (CO2, CO, NOx, N2O, UHC etc.) are established with respect to load and gas turbine performance, including performance degradation. Different NOx emission correlations are analysed based on test results, and a proposed prediction model presented. The impact of machinery performance degradation on emission levels is particularly analysed. Good agreement is achieved between measured and predicted NOx emissions from the proposed correlation.
To achieve continuous exhaust emission control, the proposed NOx model is implemented to the on-line condition monitoring system on the Sleipner A platform, rather than introducing sensitive emission sensors in the exhaust gas stack. The on-line condition monitoring system forms an important tool in detecting machinery condition/degradation, air pollution and achieving optimum energy conservation.
A Test Rig for the Identification of Rotordynamic Coefficients of Fluid Film Bearing Elements
Authors: Robison L. Miller , Arauz Grigory , San Andres Luis 
Published: February 2015

A test rig and measurement procedure to identify the rotordynamic coefficients of generic fluid film bearing elements are described. The test apparatus allows the exchange of test articles without modifications to the basic design of the machine. The maximum operating speed of the rig is 9,000 rpm, with static loads to 4,450 N (1,000 lb) and available fluid supply pressures to 689 kPa (100 psi). Impact load excitations in two orthogonal directions bring the test bearing into dynamic motion, and a data acquisition and computer system record the dynamic response at a frequency of 12,000 samples per second.
Test bearing elements undergo multiple forced dynamic tests, and the corresponding time responses are transformed into the frequency domain and averaged. Bearing stiffness, damping, and inertia force coefficients are then identified from an impedance matrix in the frequency domain. Dynamic tests for an open ends squeeze film damper at various journal center static (offset) positions are presented for three levels of impact loads. In general, the identified damping coefficients correlate well with theoretical predictions.
Status of the Automotive Ceramic Gas Turbine Development Progrem: Year Four Progress
Authors: Nishiyama Tsubura , Iwai Masumi , Nakazawa Norio , Sasaki Masafumi , Katagiri Haruo , Handa Noritoshi 
Published: February 2015

The seven-year program, designated “Research & Development of Automotive Ceramic Gas Turbine Engine (CGT Program)”, was started in 1990 with the object of demonstrating the advantageous potentials of ceramic gas turbines for automotive use. This CGT Program is conducted by Petroleum Energy Center.
The basic engine is a 100kW, single-shaft regenerative engine having turbine inlet temperature of 1350°C and rotor speed of 110000rpm.
In the forth year of the program, the engine components were experimentally evaluated and improved in the various test rigs, and the first assembly test including rotating and stationary components, was performed this year under the condition of turbine inlet temperature of 1200°C.