bluuebunny/crossref_metadata_2025_split huggingface dataset:
Propulsion System Considerations for Future Supersonic Transports: A Global Perspective
Authors: Mercure Robert A. 
Published: February 2015

With research and technology (R&T) development activities for the next generation SuperSonic Transport (SST) being pursued globally over the past few years, the options to proposed airframe and engine concepts appears to be converging. The United States, the Europeans, and the Japanese are all engaged in developing the technologies needed for a future SST that is environmentally compatible and economically practical. Boeing and McDonnell Douglas are part of the team under an R&T contract with the National Aeronautics and Space Administration to develop critical components and enabling materials that will allow industry to make a production decision by 2003. Europe’s three main aircraft manufacturer’s — i.e., Aerospatiale, British Aero-space, and Deutsche Aerospace — comprise the European Supersonic Research Program (ESRP). A primary Japanese effort called the Hypersonic Transport Propulsion System Research (HYPR) project consists of a consortium of four international engine manufacturers and the National Japanese Laboratory. The manufacturers are: Ishikawajima-Harima Heavy Industries Co. Ltd., the Kawasaki Heavy Industries Co. Ltd., Mitsubishi Heavy Industries Co. Ltd., and General Electric Aircraft Engines Company, USA. A recent study by the Japan Aircraft Development Corporation (Reference 1) also addressed the technology requirements for the next generation SST.
There are basically three major challenges that must be met before a new SST can become a reality. They are the technical, environmental, and economic challenges. The technical challenges of the propulsion system primarily reduce the development of new materials capable of sustaining higher temperatures and vibration (high and low frequency) over longer exposure times as well as capable of being produced at reasonable costs. Low emission combustors and low exhaust jet noise are the primary environmental challenges, which are a technical challenge in themselves. The economic challenge is to produce an aircraft and propulsion system that allows the manufacturers to recover development and manufacturing costs as well as realize a reasonable Return-On-Investment (ROI). In addition, Life Cycle Costs (LCC) must not be substantially above future subsonic airliners in order to justify premium fares the public would be willing to pay for the time savings of long-distance flights and still be profitable to the airlines.
A Review of Recent Research on Contra-Rotating Axial Flow Compressor Stage
Authors: Sharma P. B. , Adekoya A. 
Published: February 2015

Aero compressor technology has seen a significant advancement during the last two decades. Research on Rotor-Stator stage has focused on improvements in the design as well as off-design performance. Work has also been carried out to improve the clearance losses, stage loading as well as the stability of the operation. In this connection, the work on end-bend rotor-stator and variable geometry stators is specially significant. These efforts have however, yielded marginal improvements as far as the capability of the stage to produce pressure rise and its through-flow capacity are concerned. The interest in contra-rotation has emerged with a view to achieve considerable high pressure rise per stage besides its effects on stability of the stage to rotating stall/surge suppression. Contra-rotation concept has already found its acceptability in the development of future fuel efficient gas turbine plants and aero engines.
This paper presents a review of the experimental and theoretical investigations on the aero-dynamic and aero-acoustic performance of the contra-rotating pressure stage. The areas of future work on contra-rotation are also outlined.
Optimum Operation and Maintenance of Gas Turbines Offshore
Authors: Bakken Lars E. , Skorping Roald 
Published: February 2015

At present, offshore gas turbines are operated encouraging high thermal efficiency and low power consumption. High thermal efficiency normally demands operation close to full load, which may increase the emission of specific components.
The present emission tax on CO2 has a substantial impact on gas turbine operation and maintenance costs. At present, it is of great importance to include the influence of emission taxes by focusing on optimum energy operation and maintenance.
The influence of gas turbine degradation on operating costs is high. Analysis based on operational experience and field test performance data show an extra cost due to deterioration up to NOK 4.5 million a year. To obtain optimum energy operation and maintenance for the gas turbine drivers on Sleipner A, analysis and developments are based on:
• on-line condition monitoring, to detect machinery condition and component degradation
• prediction routines, to forecast degradation “development” as a function of time
• optimisation routines, to predict optimum intervention time based on operating and maintenance costs
• sensitivity analysis, including site performance correction to actual operating condition
The developed procedure has resulted in increased flexibility and availability, in addition to reduced operating and maintenance costs. Total potential savings are estimated up to NOK 2.5 mill. per gas turbine a year. The system forms an important tool in future operation of the 60 gas turbines in present service.
Dry Low NOx Combustion Systems Development and Operating Experience
Authors: Strand Torsten 
Published: February 2015

It is shown that emissions are becoming significant performance parameters. Dry Low NOx combustion is favourably evaluated in terms of fuel consumption when compared to NOx abatement with water injection or SCR.
The conversion of two industrial gas turbines to Dry Low NOx (DLN) Combustion summarised.
Four years experience of commissioning and operation of a number of DLN gas turbines is described.
Emission levels around 25 ppmv NOx on gas has been achieved. Operation on natural gas is generally very reliable, but some initial problems were encountered.
Emission measurements and especially continuos emission monitoring have proved to be unreliable and caused a lot of trouble during the commissioning of some plants.
Evaluation of New Process Options for Co-Generation in the Sugar Industry
Authors: Gabra M. A. , Kjellström B. O. 
Published: February 2015

Biomass fuelled combined cycle with gas turbine for co-generation, has the promise of being able to produce electricity at competitive cost. The sugar cane industries in the developing countries are targets for near term-applications of this technology.
Different options for increasing the electricity generation in the sugar mills by using more advanced steam process and combined cycle technology, using cane trash and bagasse as a fuel for has been analyzed. The TPC sugar mill in Tanzania was selected as a case study for investigation. Introduction of a combined gas turbine/steam turbine process will make it possible to increase the electricity output from 2.5 MW to 30 MW at this plant during milling season. By using cane trash as fuel during the off-season period, the electricity generation can be increased by a factor of 20 compared to what is generated at TPC sugar factory today.
The financial evaluation indicated that the annual profit would range from US$ 3.5 million for the advanced steam process with 6.5 years pay-back time, to be US$ 4.7 million for the combined gas turbine/steam turbine process with 6.8 years pay-back time.
A Simultaneous Solution Method Based on a Modular Approach for Power Plant Analyses and Optimized Designs and Operations
Authors: Cerri Giovanni 
Published: February 2015

A general method capable to solve optimization power plant problems simultaneously with the solution of equations describing the plant behavior is discussed.
The method has been implemented into CGSPO code whose main features as the plant modular structure and its automatic assembling are described.
Procedures foreseen in the code are: cycle calculations, sizing of components and off-design analysis. Examples showing the capabilities and the flexibility of the method are given.
The code is suitable for the analysis of plant including commercially available machines whose modifications to match with other components may be investigated.
Numerical Investigation of the Unsteady Transonic 3D-Flow in Stator and Rotor Cascades With Oscillating Blades
Authors: Peitsch Dieter , Gallus Heinz E. , Weber Stefan 
Published: February 2015

Subject of this paper is a numerical method for the simulation of flutter in three dimensional oscillating cascades. Unsteadiness can be caused by bending and torsional oscillation modes simultaneously. The goal of the investigation is the evaluation of the resulting blade forces and moments. The flow is assumed to be time-dependent and inviscid. By solving the Euler equations in a nonlinear way, large oscillations as well of the airfoil as of existing shocks can be treated.
The numerical solution follows a Godunov-type upwind scheme, formulated in node centered finite volume technique. An approximative Riemann solver proposed by Roe is used to determine the fluxes over the surfaces of the control volume. Since unphysical expansion shocks have to be suppressed, a modification of the transonic characteristic speeds is included. The extrapolation of the flow values onto the control volumes’ surfaces is done by means of the MUSCL technique, embedded in a TVD-scheme with the flux limiter by van Albada. The computational domain is restricted to only one channel and the periodic values are stored over one period of oscillation. A special technique is introduced, which reduces both the effort in CPU-time and in computer memory. Results are included for compressor and turbine geometries in sub- and transonic flow.
Development of the Sequential Combustion System for the ABB GT24/GT26 Gas Turbine Family
Authors: Joos Franz , Brunner Philipp , Schulte-Werning Burkhard , Syed Khawar , Eroglu Adnan 
Published: February 2015

The 60Hz, 165MW gas turbine GT24 and the 50Hz, 240MW gas turbine GT26 are the first two members of ABB’s Sequential Combustion System gas turbine family. These turbines are designed to offer increased output at up to 4% efficiency advantage over today’s engines. Whereas the first combustor is based on the proven EV-combustor technology, an extensive research and development program has been carried out in developing the lean premixed, self-igniting second combustor.
This paper reports the basic research work concerning the lean premixing burners with self-ignition. The development of the burner and the combustor was based on wind tunnel and water channel experiments, CFD-calculations and combustion tests at atmospheric and high pressure.
Moreover an innovative cooling technology was developed to fullfill all conditions of the self-igniting premix combustor requiring minimal cooling air consumption. Special attention was paid both to a low sensitivity of the cooling effectiveness to variations of the imposed boundary conditions and to a robust hardware construction.
Tests of real engine parts at real engine conditions will be demonstrated in detail. Finally the paper demonstrates the potential of the sequential combustion system to reach single digit NOx levels by unveiling the results of the extensive testing program.
Experimental Assessment of the Emissions Benefits of a Ceramic Gas Turbine Combustor
Authors: Smith K. O. , Fahme A. 
Published: February 2015

Three subscale, cylindrical combustors were rig tested on natural gas at typical industrial gas turbine operating conditions. The intent of the testing was to determine the effect of combustor liner cooling on NOx and CO emissions.
In order of decreasing liner cooling, a metal louvre-cooled combustor, a metal effusion-cooled combustor, and a backside-cooled ceramic (CFCC) combustor were evaluated. The three combustors were tested using the same lean-premixed fuel injector.
Testing showed that reduced liner cooling produced lower CO emissions as reaction quenching near the liner wall was reduced. A reduction in CO emissions allows a reoptimization of the combustor air flow distribution to yield lower NOx emissions.
The Offshore Application of a Dual-Mode Injection Centrifugal Compressor and Improvements to Rotating Stall
Authors: Lynghjem Arne , Svendsen Ove , Underbakke Harald 
Published: February 2015

This paper covers the experience from the retrofit of a new dual-mode injection compressor into the existing gas compression facilities on an offshore platform. The implementation of this new and innovative compressor technology made it possible to fulfil new requirements to higher throughput, different kind of service, improved safety level and economical operation.
But then the compressor exhibited gas dynamic instability — determined as rotating stall in the impeller — a phenomenon not well understood. The literature on this topic is scare. The rotating stall phenomenon caused a significant reduction in useful operational area of the compressor. An improvement program was carried out. Changes in the impeller geometry led to restoration of the expected operational range. The magnitude of the phenomenon has diminished partially also. Rotating stall criteria proved to be useful in order to improve or avoid rotating stall problems in a centrifugal compressor.
The dual-mode injection compressor allowed decommissioning of a whole equipment module, which represents a very useful experience factor in the design of new offshore platforms. The compressor has been in operation since November 1994, and it has been able to fulfil all specified operating requirements.
Using an Auxiliary Power Unit (APU) Gas Turbine Engine to Start the LSD-41 Class Diesel Engines
Authors: Patterson Jeffrey S. 
Published: February 2015

The LSD-41 Whidbey Island Class of Amphibious dock landing ships are powered by two Colt-Pielstick PC2.5V Block 16 cylinder Main Propulsion Diesel engines. These engines represent the largest diesels in the U.S. Navy. Currently, they are started without the use of a mechanical starter, by injecting 100 cfm [47.2 LPs] of 3,000 psig [206.9 barr] high pressure air, reduced to 425 psig [29.3 barr] directly into one block of eight engine cylinders. Naval Surface Warfare Center, Carderock Division (NSWCCD) was tasked to perform a proof of concept test that would demonstrate the capability of an Auxiliary Power Unit (APU) gas turbine engine to start these large, medium speed diesel engines.
This paper will present the background, installation and initial testing for this proof of concept test. The background section will discuss the test philosophy, the LSD-41 Land Based Engineering Site (LBES) and initial prototype testing. The installation section will discuss the modifications made to the LBES for this test and the characteristics and specifications of the test hardware. The testing section will discuss the test plan and the test procedures.
This paper will not present any results or data analysis from this proof of concept test. Test site availability and equipment procurement delays postponed the start of this test until March, 1996. Therefore, the test results will be discussed at the upcoming Turbo Exposition conference.
Dynamic Modeling of Single-Shaft Industrial Gas Turbine
Authors: Bettocchi R. , Spina P. R. , Fabbri F. 
Published: February 2015

In the paper the dynamic non-linear model of single shaft industrial gas turbine was developed as the first stage of a methodology aimed at the diagnosis of measurement and control sensors and gas turbine operating conditions.
The model was calibrated by means of reference steady-state condition data of a real industrial gas turbine and was used to simulate various machine transients.
The model is modular in structure and was carried out in simplified form, but not so as to compromise its accuracy, to reduce the calculation time and thus make it more suitable for on-line simulation.
The comparison between values of working parameters obtained by the simulations and measurements during some transients on the gas turbine in operation provided encouraging results.
Development of Blade Profiles for Low Pressure Turbine Applications
Authors: Curtis E. M. , Hodson H. P. , Banieghbal M. R. , Denton J. D. , Howell R. J. , Harvey N. W. 
Published: February 2015

This paper describes a programme of work, largely experimental, which was undertaken with the objective of developing an improved blade profile for the low-pressure turbine in aero-engine applications.
Preliminary experiments were conducted using a novel technique. An existing cascade of datum blades was modified to enable the pressure distribution on the suction surface of one of the blades to be altered. Various means, such as shaped inserts, an adjustable flap at the trailing edge, and changing stagger were employed to change the geometry of the passage. These experiments provided boundary layer and lift data for a wide range of suction surface pressure distributions. The data was then used as a guide for the development of new blade profiles. The new blade profiles were then investigated in a low-speed cascade that included a set of moving bars upstream of the cascade of blades 10 simulate the effect of the incoming wakes from the previous blade row in a multistage turbine environment.
Results are presented for two improved profiles that are compared with a datum representative of current practice. The experimental results include loss measurements by wake traverse, surface pressure distributions, and boundary layer measurements. The cascades were operated over a Reynolds Number range from 0.7 × 105 to 4.0 × 105. The first profile is a “laminar flow” design that was intended to improve the efficiency at the same loading as the datum. The other is a more highly loaded blade profile intended to permit a reduction in blade numbers. The more highly loaded profile is the most promising candidate for inclusion in future designs. It enables blade numbers to be reduced by 20%, without incurring any efficiency penalty. The results also indicate that unsteady effects must be taken into consideration when selecting a blade profile for the low-pressure turbine.
Ceramic Gas Turbine Technology Development
Authors: Easley M. L. , Smyth J. R. 
Published: February 2015

Under the U.S. Department Of Energy/National Aeronautics and Space Administration (DOE/NASA) funded Ceramic Turbine Engine Demonstration Program, AlliedSignal Engines is addressing the remaining critical concerns slowing the commercialization of structural ceramics in gas turbine engines. These issues include demonstration of ceramic component reliability, readiness of ceramic suppliers to support ceramic production needs, and enhancement of ceramic design methodologies.
The AlliedSignal/Garrett Model 331-200[CT] Auxiliary Power Unit (APU) is being used as a ceramics test bed engine. For this program, the APU First-stage turbine blades and nozzles were redesigned using ceramic materials, employing the design methods developed during the earlier DOE/NASA funded Advanced Gas Turbine (AGT) and Advanced Turbine Technologies Application Project (ATTAP) programs. The present program includes ceramic component design, fabrication, and testing, including component bench tests and extended engine endurance testing and field testing. These activities will demonstrate commercial viability of the ceramic turbine application. In addition, manufacturing process scaleup for ceramic components to the minimum level for commercial viability will be demonstrated.
Significant progress has been made during the past year. Engine testing evaluating performance with ceramic turbine nozzles has accumulated over 910 hours operation. Ceramic blade component tests were performed to evaluate the effectiveness of vibration dampers and high-temperature strain gages, and ceramic blade strength and impact resistance. Component design technologies produced impact-resistance design guidelines for inserted ceramic axial blades, and advanced the application of thin-film thermocouples and strain gages on ceramic components. Ceramic manufacturing scaleup activities were conducted by two ceramics vendors, Norton Advanced Ceramics (East Granby, CT) and AlliedSignal Ceramic Components (Torrance, CA). Following the decision of Norton Advanced Ceramics to leave the program, a subcontract was initiated with the Kyocera Industrial Ceramics Company Advanced Ceramics Technology Center (Vancouver, WA). The manufacturing scaleup program emphasizes improvement of process yields and increased production rates.
Work summarized in this paper was funded by the U.S. Dept. Of Energy (DOE) Office of Transportation Technologies, part of the Turbine Engine Technologies Program, and administered by the NASA Lewis Research Center, Cleveland, OH under Contract No. DEN3-335.
Unsteady Flow in Oscillating Turbine Cascade: Part 1 — Linear Cascade Experiment
Authors: He L. 
Published: February 2015

An experimental and computational study has been carried out on a linear cascade of low pressure turbine blades with the middle blade oscillating in a torsion mode. The main objectives of the present work were to enhance understanding of the behaviour of bubble type of flow separation and to examine the predictive ability of a computational method. In addition, an attempt was made to address a general modelling issue: was the linear assumption adequately valid for such kind of flow?
In Part 1 of this paper, the experimental work was described. Unsteady pressure was measured along blade surfaces using off-board mounted pressure transducers at realistic reduced frequency conditions. A short separation bubble on the suction surface near the trailing edge and a long leading-edge separation bubble on the pressure surface were identified. It was found that in the regions of separation bubbles, unsteady pressure was largely influenced by the movement of reattachment point, featured by an abrupt phase shift and an amplitude trough in the 1st harmonic distribution. The short bubble on the suction surface seemed to follow closely a laminar bubble transition model in a quasi-steady manner, and had a localized effect. The leading-edge long bubble on the pressure surface, on the other hand, was featured by a large movement of the reattachment point, which affected the surface unsteady pressure distribution substantially. As far as the aerodynamic damping was concerned, there was a destabilizing effect in the separated flow region, which was however largely balanced by the stabilizing effect downstream of the reattachment point due to the abrupt phase change.