bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Low-Emission Combustor for a 100-kW Automotive Ceramic Gas Turbine (III)
Authors: Sasaki Masafumi , Kumakura Hirotaka , Suzuki Daishi , Ichikawa Hiroyuki , Ohkubo Youichiro , Yoshida Yuusaku 
Published: February 2015

A low emission combustor, which uses a prevaporization-premixing lean combustion system for the 100 kW automotive ceramic gas turbine (CGT), has been subjected to performance tests. Now a second combustor prototype (PPL-2), which incorporates improvements intended to overcome a flashback problem observed in an initial combustor prototype (PPL-1), is tested.
The PPL-2 has been designed and built, so that it will substantially expand the stable combustion range. The improvement is accomplished by increasing the air distribution ratio in the lean combustion region to avoid flashback, providing a uniform flow velocity through the throat area and also by diluting the boundary layer so as to suppress flashback. Test results of the PPL-2 combustor show that it expands the flashback limit without affecting the blow out limit and is able to cover the stable combustion range need for the 100kW CGT.
Integrated Gas Turbine Technology Education at Durham University
Authors: Marsh Harry , Dominy Robert , Gregory-Smith David , He Li 
Published: February 2015

Gas turbine technology is a major component in the teaching and research programmes at Durham University. In 1993, the change from the three-year degree course to the four-year Master of Engineering course provided an opportunity to strengthen the teaching of turbomachinery through closer integration of lectures, laboratory work, design, investigative project work and the use of computers for flow prediction. The undergraduate projects link with research in turbomachinery aerodynamics, secondary flows, and unsteady flows. The integrated approach provides graduates with a broad based education and a good understanding of turbomachinery.
Wider aspects include the placement of students for a year of industrial training with a European turbine manufacturer and the organisation of an two-week course for industry on turbine technology. An unusual feature of the Durham approach is the development of turbomachinery based projects to introduce the challenge of engineering into schools and colleges.
Development of a Dual-Fuel Injection System for Lean Premixed Industrial Gas Turbines
Authors: Cowell Luke H. , Rajput Amjad , Rawlins Douglas C. 
Published: February 2015

A fuel injection system for industrial gas turbine engines capable of using natural gas and liquid fuel in dry, lean premixed combustion is under development to significantly reduce NOx and CO emissions. The program has resulted in a design capable of operating on DF#2 over the 80 to 100% engine load range meeting the current TA LUFT regulations of 96 ppm (dry, @ 15% O2) NOx and 78 ppm CO. When operating on natural gas the design meets the guaranteed levels of 25 ppm NOx and 50 ppm CO.
The design approach is to apply lean premixed combustion technology to liquid fuel. Both injector designs introduce the majority of the diesel fuel via airblast alomization into a premixing passage where fuel vaporization and air-fuel premixing occur. Secondary fuel injection occurs through a pilot fuel passage which operates in a partially premixed mode. Development is completed through injector modeling, flow visualization, combustion rig testing, and engine testing. The prototype design tested in development engine environments has operated with NOx emissions below 65 ppm and 20 ppm CO at full load. This paper includes a detailed discussion of the injector design and qualification testing completed on this development hardware.
Operational Experience With the World’s First Offshore Turboexpanders With Magnetic Bearings
Authors: Underbakke Harald 
Published: February 2015

The first offshore turboexpanders with magnetic bearings have now been in operation on the Sleipner A platform in the North Sea since October 1993.
Four machines are installed, each at 3.3 MW, running at 16,500 RPM for natural gas dew point control.
During the commissioning phase and the first year of operation a number of problems were discovered, mainly due to the application of magnetic bearings in a new environment, and some unexpected bearing / process interaction phenomenon.
To solve the problems it was necessary to do modifications to electrical systems, mechanical parts, operational procedures and buffer gas systems.
After a 1.5 year period of modifications, all 4 machines are now running with 99 % availability.
Three Dimensional Analysis of Advanced Swirl Vane/Nozzle Assemblies
Authors: Micklow Gerald J. , Benjamin Michael 
Published: February 2015

The performance of high shear axial inflow/radial outflow airblast fuel injectors for advanced gas turbine combustors is highly dependent on the design of the swirl vanes. 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.
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.
The present study investigates two curved swirler/nozzle shroud configurations operating at 1 and 10 atmospheres pressure for the same inlet temperature of 293°K. The first configuration was a twisted curved vane with thickness where the turning angle varied non-linearly from hub to tip with a maximum turning at the tip of 70 degrees. The second configuration was a curved vane with a linear variation of turning with 70 degrees turning at the tip. The results from a three dimensional viscous numerical flow simulation of these configurations shows similar performance for all cases investigated. The non-linear twisted vane however, had an approximately 3% higher mass flow rate than the vane with the linear variation in turning for the same exit static pressure at the hub. One problem which existed for all the conditions analyzed was a high loss region near the vane tip. This was due to the interaction with the shroud. As the flow exits the vane row and progresses along the nozzle outer lip, the flow area increases. This condition along with the streamline curvature effect of the outer nozzle lip causes an adverse pressure gradient to be formed in this region. This adverse pressure gradient causes the flow to separate from the vane suction surface. The problem initiated in the region of 70% span and increased in magnitude to the vane tip.
Optimization of Transient Heat Transfer Measurements Using Thermochromic Liquid Crystals Based on an Error Estimation
Authors: Höcker Rainer 
Published: February 2015

An analytical investigation has been made to identify and quantify critical parameters influencing the final result of a transient heat transfer experiment. The aim was to obtain a set of dimensionless parameters, that describe the interaction of the individual measured quantities in a compact form.
Among the wide variety of different kinds of heat transfer measurement techniques, the transient method, employing thermochromic liquid crystals, is very useful. It gives much detailed heat transfer information with a minimum effort in experimental time. The present paper focuses on this technique, although it is not the only choice for all kinds of applications, but it is the currently most frequently used one.
This paper provides the means to lay out an experiment, so that it yields acceptable results with respect to the constraints for a set of test boundary conditions.
Invariant Coordinate Systems for Compressor Control
Authors: Batson B. W. 
Published: February 2015

To protect a compressor from surge, it is necessary to accurately calculate the location of the interface between stable operation and surge. Describing the Surge Limit Interface in certain coordinate systems results in a surface which is invariant to compressor suction conditions such as temperature and molecular weight. We refer to these coordinates as invariant coordinates. We explore these invariant coordinate systems and some nearly invariant systems useful for antisurge control. Some of them are commonly used in the industry, others are quite novel. This work serves to point out the unifying basis of them all.
The applications for these methods are mainly industrial compressors. Varying molecular weight represents the main challenge since a real-time measurement for this parameter is unavailable.
We present compressor maps constructed from test data in these coordinates. The validity of this approach is well supported by these data.
Cooling and Sealing Air System in Industrial Gas Turbine Engines
Authors: Reichert A. W. , Janssen M. 
Published: February 2015

Siemens heavy duty Gas Turbines have been well known for their high power output combined with high efficiency and reliability for more than 3 decades. Offering state of the art technology at all times, the requirements concerning the cooling and sealing air system have increased with technological development over the years. In particular the increase of the turbine inlet temperature and reduced NOx requirements demand a highly efficient cooling and sealing air system. The new Vx4.3A family of Siemens gas turbines with ISO turbine inlet temperatures of 1190°C in the power range of 70 to 240 MW uses an effective film cooling technique for the turbine stages 1 and 2 to ensure the minimum cooling air requirement possible. In addition, the application of film cooling enables the cooling system to be simplified. For example, in the new gas turbine family no intercooler and no cooling air booster for the first turbine vane are needed.
This paper deals with the internal air system of Siemens gas turbines which supplies cooling and sealing air. A general overview is given and some problems and their technical solutions are discussed. Furthermore a state of the art calculation system for the prediction of the thermodynamic states of the cooling and sealing air is introduced. The calculation system is based on the flow calculation package Flowmaster (Flowmaster International Ltd.), which has been modified for the requirements of the internal air system. The comparison of computational results with measurements give a good impression of the high accuracy of the calculation method used.
Jet, Wake and Intrinsic Motion in Impellers of Centrifugal Compressors
Authors: Chen Y. N. , Seidel U. , Haupt U. , Rautenberg M. 
Published: February 2015

It was shown in a previous paper of the authors (1991) that jet and wake in the flow of the impeller of the centrifugal compressor are developed from the Dean’s type vortex pair formed in the curvature of the blade channel. The jet rotating against the sense of the impeller is weakened, and the wake rotating in the sense of the impeller is enhanced during travelling with the flow toward the outlet. This property is attributed to the conservation of the potential vorticity of the vortex. The experimental result obtained by Krain (1984) has confirmed this theory.
The secondary flows found by Farge and Johnson (1990) enable the determination of the vorticity of the wake at the outlet of the impeller. It amounts to 6.9 Ω and 5.8 Ω for the radial-blading and the 60°-backswept blading impeller, respectively. The intensity of the vortex jet is weakened to undetectable value for both the impellers. The patterns of these secondary flow fields are also quite different between these two kinds of impellers. Whilst that of the former is controlled by the intrinsic motion, that of the latter is governed by the relative velocity along the blades.
Furthermore, the experimental result obtained by the injection of colored dye at the impeller outlet and the measured velocity field around the impeller reveal an intense reverse flow in the radial blading impeller, travelling from the outlet toward the inlet, along the shroud. It can be shown that this reverse flow is caused by the intrinsic motion occuring in this impeller and impinging on the leading edge of the diffuser vane. As the rotating stall is introduced by the reverse flow, the low-solidity vaned diffuser, and still better the vaneless diffuser can therefore shift the stall line to a very low flow rate.
Role of Environmental Deposits in Spallation of Thermal Barrier Coatings on Aeroengine and Land-Based Gas Turbine Hardware
Authors: Borom Marcus P. , Johnson Curtis A. , Peluso Louis A. 
Published: February 2015

Thermal barrier coating (TBC) spallation on power generation combustors was compared with TBC spallation observed both in military turboshaft engines, and in commercial turboprop engines. In each case, irrespective of operating conditions or geographic location, spallation was linked to the presence and infiltration of high temperature molten phases of similar composition. Electron microprobe analysis found that, from all the possible oxides available in the external environment, only CaO, MgO, Al2O3 and SiO2 (CMAS) are incorporated in the molten phase that infiltrates the TBC microstructure. Iron and nickel oxides from turbine components and zirconia and yttria from the TBC were also found in varying amounts in the molten phase.
Melting of environmental deposits in conjunction with infiltration was found to result in: densification of the TBC, an increase in its Young’s modulus and an increase in the room temperature compressive stress in the TBC. Delamination of the TBC during thermal cycling is, thereby, attributed to changes in the mechanical properties and associated changes in the stress state of the coating due to infiltration of the environmental deposit.
Design of the Tempest Industrial Gas Turbine
Authors: Scott Kevin R. , Amos Ian G. , Garbett Paul D. P. , Wells Roger G. 
Published: February 2015

The Tempest is the most recent power generation package produced by European Gas Turbines in England. It is currently in the evaluation phase of a 3 year program leading to production in 1996 at 7.5MWe and single-shaft configuration.
The machine has been designed for base load operation using gas and liquid fuels and is particularly suitable for combined heat and power applications. It is a development of the existing Typhoon and Tornado family of engines but includes a number of features to enhance its performance.
This paper discusses the design techniques and describes the gas turbine engine core. It also presents the design validation and service recommendations.
Development of Advanced Gas Turbine
Authors: Matsuzaki H. , Suto Y. , Kanazawa Y. , Sato M. , Kobayashi I. , Kobayashi Y. 
Published: February 2015

There is a strong demand for efficient and clean power generation systems which can cope with the energy shortage and the global environmental problems.
As one of the measures to meet this demand, Tohoku Electric Power Company, in cooperation with the three domestic gas turbine manufacturers, has been developing since 1989 the key technologies for the next generation high efficiency gas turbine of a 1,500°C class of firing temperature.
The aim is to achieve over 55% (LHV) thermal efficiency in a LNG comhined cycle power plant.
In this research, Tohoku Electric Power Company have developed: (1) advanced cooling schemes for 1st stage vanes and blades, (2) heat resistant materials for 1st stage vanes and blades and (3) high temperature low NOx combustor, which are the key technologies required for realizing a 1,500 °C class high efficiency gas turbine with a potential for practical use.
Numerical Simulation of Particulate Two-Phase Flows in Curved Pipeline Geometries
Authors: Naik S. 
Published: February 2015

The flow of particulate two-phase flow mixtures occur in several components of solid fuel combustion systems, such as the Pressurised Fluidised Bed Combustors (PFBC) and suspension fired coal bailers. A detailed understanding of the mixture characteristics in the conveying component can aid in refining and optimising its design. In this study, the flow of an isothermal, dilute two-phase particulate mixture has been examined in a high curvature duct, which can be representative of that transporting the gas-solid mixture from the hot clean-up section to the gas turbine combustor in a PFBC plant.
The numerical study has been approached by utilising the Eulerian-Lagrangian methodology for describing the characteristics of the fluid and particulate phases. By assuming that the mixture is dilute, the governing particle momentum equations have been solved with appropriately prescribed boundary conditions. The influence of the turbulence on the particle dispersion was represented by a stochastic model.
For the turbulent flow condition examined, it was observed that mixtures with small particle diameters had low inter-phase slip velocities and low impaction probability with the pipe walls. Increasing the particle diameters (> 50 um) resulted in higher inter-phase slip velocities and as expected their impaction probability with the pipe walls was significantly increased. The particle dispersion is significant for the smaller sizes whereas the larger particles are relatively insensitive to turbulence. The main particle impaction region, and location most prone to erosion damage, is estimated to be within an outer duct length of 2 to 5 times the duct diameter.
Manufacturing Methods, Random Defects and Quality Assurance in Relation to the Reliability of Turbine Components
Authors: Mitchell A. 
Published: February 2015

The present methods for life prediction in rotating parts rely heavily on an assumed distribution of potential crack initiation sites, corresponding to a distribution of properties which is determined from laboratory testing of samples of the alloy. However, as the expectations of the designer extend into increasing reliable life and also come closer to the limits of alloy performance, we also approach the limits of validity of the statistical methods used in property specification, raising the problem of the rare random defect which may be present in spite of the installed production control methodologies. This type of defect may be found in all alloys, but the specific form depends on the alloy and on the manufacturing method. In this work we give examples for high-strength steels, superalloys and titanium alloys.
We propose that the most effective solution to this problem lies in the more vigorous application of process control within manufacturing fixed practices, ensuring the absence of this type of defect through control and data acquisition techniques which can identify a process anomaly and trigger rejection or down-grading of the product.
Flow in a Rotating Cavity With a Peripheral Inlet and Outlet of Cooling Air
Authors: Gan Xiaopeng , Mirzaee Iraj , Owen J. Michael , Rees D. Andrew S. , Wilson Michael 
Published: February 2015

In some engines, corotating gas–turbine discs are cooled by air introduced at the periphery of the system. The air enters through holes in a stationary peripheral casing and leaves through the rim seals between the casing and the discs. This paper describes a combined computational and experimental study of such a system for a range of flowrates and for rotational Reynolds numbers of up to Reϕ = 1.5 × 106. Computations are made using an axisymmetric elliptic solver, incorporating the Launder–Sharma low–Reynolds–number k–ε turbulence model, and velocity measurements are obtained using laser–Doppler anemometry.
The stationary peripheral casing creates a recirculation region: there is radial outflow in boundary layers on the discs and inflow in the core between the boundary layers. The radial extent of the recirculation region increases as the flow rate increases and as the rotational speed decreases. In the core, the radial and tangential components of velocity, Vr and Vϕ, are invariant in the axial direction, and the measured values of Vϕ conform to a Rankine–vortex flow. The agreement between the computed and measured velocities is not as good as that found for other rotating–disc systems, and deficiencies in the turbulence model are believed to be responsible.
The Design and Evaluation of a 14 Stage, 16:1 Pressure Ratio Compressor for an Industrial Gas Turbine
Authors: Saadatmand Mohammad R. 
Published: February 2015

The aerodynamic design process leading to the production configuration of a 14 stage, 16:1 pressure ratio compressor for the Taurus 70 gas turbine is described. The performance of the compressor is measured and compared to the design intent. Overall compressor performance at the design condition was found to be close to design intent. Flow profiles measured by vane mounted instrumentation are presented and discussed.
The flow through the first rotor blade has been modeled at different operating conditions using the Dawes (1987) three-dimensional viscous code and the results are compared to the experimental data. The CFD prediction agreed well with the experimental data across the blade span, including the pile up of the boundary layer on the corner of the hub and the suction surface. The rotor blade was also analyzed with different grid refinement and the results were compared with the test data.
Sea Trials/Commissioning of a Gas Turbine Powered High Speed Passenger Vessel
Authors: Waldhelm Chris , Warren Nigel 
Published: February 2015

The demand for higher vessel speeds and passenger comfort have led to the development of improved hull designs in conjunction with power plants of high specific power and low emissions capabilities inherent in gas turbines. In early 1993, FBM Marine began design and construction of a 45 meter Solent class hulled catamaran with a partial third hull, named TriCat, for 332-passenger service at greater than 45 knots. The power plant selected consists of two Solar Turbines Taurus 60M industrial derivative marine gas turbines driving KaMeWa AB Series 90S11 waterjets through Philadelphia Gear Corporation 1000 VMGH-HP2S speed reduction drives for a total shaft output power of 10.2 MW (equivalent ISO with inlet and exhaust losses).
The Taurus 60M gas turbines, each ISO rated at 5250 kW MCR (without losses), the gearbox and control system were type approved and certified by Det Norske Veritas (DNV) in 1994 prior to issuance of the Certificate of Conformity of the total propulsion package. The sea trials of the TriCat were initiated late 1994 off the Isle of Wight in the UK. After Honk Kong Marine Department approval in early 1995, the owner/operator of the five vessels, CTS-Parkview, began passenger service in June 1995 between Hong Kong and Macau.
This paper discusses the sea trials and commissioning process including improvements incorporated prior to initiation of passenger service on the TriCat.