bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ceramics-to-Metal Joining Technology for Gas Turbine Rotors
Authors: Sakamoto T. , Horinouchi H. , Maeda T. 
Published: March 2015

The joining technology of a ceramic wheel and a metal shaft for a ceramic turbocharger rotor was reviewed. The braze-bonded cup-joint method which has established for the ceramic turbocharger rotors was revealed to be effective for the gas turbine applications, in which the temperature of a joining reached to 700°C at turbine inlet temperature of 1371°C.
Slip resistance and bend strength of ceramic shaft was completed by selecting the metal sleeve and braze materials and design with FEM.
The reliability and the durability of the joining was confirmed by cyclic exposure test between 150°C and 700°C for 1000 cycles and 200 hour oxidation test.
Introduction and Application of Modular Turbine Engine Performance Analyses System Within KLM Royal Dutch Airlines
Authors: Schröder Willem J. , Lanser Harmen 
Published: March 2015

KLM Royal Dutch Airlines has successfully been using the General Electric Ground-based Engine Monitoring (GEM) system for overall monitoring of on-wing engines for several years.
GEM provides a function for the modular analysis of engines with the Turbine Engine Modular Performance Estimation Routine (TEMPER).
This paper describes the introduction and first applications of the Test Cell TEMPER routine within KLM for the CF6-50 and CF6-80 engines.
The subjects to be discussed include a short description, the installation and the evaluation of the Test Cell TEMPER function. Furthermore, KLM’s first experience with Test Cell TEMPER and KLM’s plans with TEMPER for the near future are discussed.
Effects of Endwall Suction and Blowing on Compressor Stability Enhancement
Authors: Lee N. K. W. , Greitzer E. M. 
Published: March 2015

An experimental investigation was carried out to examine the effects on stall margin of flow injection into, and flow removal out of, the endwall region of an axial compressor blade row. A primary objective of the investigation was clarification of the mechanism by which casing treatment (which involves both removal and injection) suppresses stall in turbomachines. To simulate the relative motion between blade and treatment, the injection and removal took place through a slotted hub rotating beneath a cantilevered stator row. Overall performance data and detailed (time-averaged) flowfield measurements were obtained.
Flow injection and removal both increased the stalling pressure rise, but neither was as effective as the wall treatment. Removal of high blockage flow is thus not the sole reason for the observed stall margin improvement in casing or hub treatment, as injection can also contribute significantly to stall suppression. The results also indicate that the increase in stall pressure rise with injection is linked to the streamwise momentum of the injected flow, and it is suggested that this should be the focus of further studies.
Performance of Hot Gas Clean-Up Devices Tested at the NYU DOE-PFBC Facility
Authors: Zakkay V. , Gbordzoe E. A. M. , Sellakumar K. M. , Lu C. Q. 
Published: March 2015

Three hot gas clean up units namely, the Screenless Granular Bed Filter (GBF), Ceramic Cross-flow Filter (CXF) and High Temperature, High Pressure Electrostatic Precipitator (ESP) designed for PFBC combined cycle power applications were tested at the New York University (NYU) DOE-PFBC facility located at Westbury, New York using a 780 mm ID pressurized fluidized bed combustor. The combustor was operated up to 10 atma and 870 °C.
With the exception of the ESP whose performance was hampered by persistent electrode bushing failure, the particulate capturing efficiencies of the GBF and the CXF were predominantly in the upper 90 % range. The dust loading leaving the filters was consistently lower than the NSPS particulate emission limit. The results also indicate that the filter exit gas stream may meet the gas turbine particulate tolerance limit.
None of the three high temperature, high pressure (HTHP) gas clean up units tested emerges as a favorite for use in cleaning PFBC exhaust stream because, each has mechanical design as well as operational flaws which could be corrected. The Cross-flow filter suffered from filter element cracking or delamination or gasket failure during its short test program. The backpulse cleaning system also needs to be optimized. The GBF is susceptible to media bubbling and granule flow problems through its lower seal leg. The Electrostatic Precipitator tested at NYU failed because its electrode bushings cracked due to overheating and could not hold their designed voltage.
Further HTHP filter testing at the sub-pilot plant scale is necessary to optimize filter design and develop effective operational procedures for the hot gas clean up systems that will make them viable for commercial PFBC application.
Effect of Acceleration on the Heat Transfer Coefficient on a Film Cooled Surface
Authors: Ammari H. D. , Hay N. , Lampard D. 
Published: March 2015

Results are presented of an experimental investigation into the influence of mainstream acceleration on the heat transfer coefficient downstream of injection through a row of 35° holes in a flat plate. A mass transfer analogue technique was used, with two uniform acceleration parameters, K (=ν(du∞/dx)/u∞2), of 1.9 × 10−6 and 5.0 × 10−6 in addition to the zero acceleration base-line case.
Two injectants, air and carbon dioxide, were employed to give coolant to mainstream density ratios of 1.0 and 1.52 respectively. The blowing rate varied from 0.5 to 2.0.
The heat transfer coefficient beneath the film reduced progressively as the acceleration increased, with maximum reductions from the zero acceleration datum case of about 27%. In the presence of acceleration, the heat transfer coefficient at a given blowing rate was dependent on the density ratio, an increase in the density ratio leading to a decrease in the heat transfer coefficient. An empirical correlation of the data over most of the range of densities and blowing rates of the experiments has been developed.
Towards Improved Throughflow Capability: The Use of 3D Viscous Flow Solvers in a Multistage Environment
Authors: Dawes W. N. 
Published: March 2015

A methodology is presented for simulating turbomachinery blade rows in a multistage environment by deploying a standard 3D Navier-Stokes solver simultaneously on a number of blade rows. The principle assumptions are that the flow is steady relative to each blade row individually and that the rows can communicate via inter-row mixing planes. These mixing planes introduce circumferential averaging of flow properties but preserve quite general radial variations. Additionally, each blade can be simulated in 3D or axisymmetrically (in the spirit of throughflow analysis) and a series of axisymmetric rows can be considered together with one 3D row to provide, cheaply, a machine environment for that row.
Two applications are presented: a transonic compressor rotor and a steam turbine nozzle guide vane simulated both isolated and as part of a stage. In both cases the behaviour of the blade considered in isolation was different to when considered as part of a stage and in both cases was in much closer agreement with the experimental evidence.
Secondary Flow Measurements in a Turbine Cascade With High Inlet Turbulence
Authors: Gregory-Smith D. G. , Cleak J. G. E. 
Published: March 2015

Measurements of the mean and turbulent flow field have been made in a cascade of high turning turbine rotor blades. The inlet turbulence was raised to 5% by a grid placed upstream of the cascade, and the secondary flow region was traversed within and downstream of the blades using a 5 hole probe and crossed hot-wires. Flow very close to the end wall was measured using a single wire placed at several orientations. Some frequency spectra of the turbulence were also obtained.
The results shows that the mean flow field is not affected greatly by the high inlet turbulence. The Reynolds stresses were found to be very high, particularly in the loss core. Assessment of the contributions to production of turbulence by the Reynolds stresses show that the normal stresses have significant affects as well as the shear stresses. The calculation of eddy viscosity from two independent shear stresses show it to be fairly isotropic in the loss core. Within the blade passage, the flow close to the end wall is highly skewed and exhibits generally high turbulence. The frequency spectra show no significant resonant peaks, except for one at very low frequency, attributable to an acoustic resonance.
Parametric and Numerical Study of Fully-Developed Flow and Heat Transfer in Rotating Rectangular Ducts
Authors: Iacovides H. , Launder B. E. 
Published: March 2015

This work is concerned with fully-developed constant-density turbulent flow through rectangular straight ducts rotating in an orthogonal mode. Ducts of both square and 2:1 aspect ratio cross-sections have been examined. For the square duct, predictions have been performed for Reynolds numbers of 33,500 and 97,000 and for the 2:1 aspect ratio duct the computations were carried out for a Reynolds number of 33,500. Values of the inverse Rossby number (Ro = ΩD/Wb) ranged from 0.005 to 0.2. Except in the immediate vicinity of the wall, the standard high-Reynolds-number version of the k-ε model is used to account for the effects of turbulence. Across the near-wall sublayer the damping of turbulence is modelled through a low-Reynolds-number one-equation model.
Low rotational speeds cause the formation of a pair of symmetric streamwise vortices. At higher rotational speeds, flow instabilities on the pressure side lead to transition to a more complex four-vortex structure. The transition point depends on both the cross-sectional geometry and the flow Reynolds number. Moreover, over a range of Rossby number, either two- or four-vortex solutions are possible depending upon initial conditions.
The rotation leads to significant differences between the values of friction factor and Nusselt number on the suction and pressure surfaces of the duct. The degree of heat transfer augmentation on the pressure side is found to depend on the Reynolds number as well as on Rossby number. In contrast, heat-transfer attenuation on the suction side is only Rossby-number dependent.
Limit Cycle Vibration Analysis of a Long Rotating Cylinder Partially Filled With Liquid
Authors: Colding-Jørgensen Jørgen 
Published: March 2015

The dynamics of a long, stiff cylinder, flexibly suspended at the ends, partially filled with liquid, is analyzed for varying rotating speed.
It appears from the analysis that in the absence of external damping, two distinct speed ranges with unstable whirl are present, as opposed to one instability region for the short cylinder which has been analyzed by a number of authors (Kuipers, 1964), Wolf (1968).
This is in agreement with field experience with centrifuges, where several regions of instability are often encountered, each corresponding to a particular vibration mode. The results should also apply to a jet engine with oil accidentally trapped in the rotor, or any hollow rotor with liquid trapped in the cavity.
When external damping is applied, the linear theory predicts the rotor be unstable at all speeds (Kuipers, 1964).
This is clearly not in accordance with field experience, and other authors have suggested different types of non-linear analysis which can give finite amplitude stable whirl or pulsating whirl (Berman et al., 1985).
In the present analysis a simplified non-linear analysis known as the hydraulic jump approximation is applied in the two unstable speed ranges predicted by the linear theory, and a stable whirl finite amplitude, dependent on the external damping, follows.
It is argued that the amplitudes found this way should always be higher than those predicted by a more sophisticated analysis, and also higher than the amplitudes measured by other authors, so that the procedure described should give a safe worst case prediction of rotor whirl amplitudes for a given external damping.
Finally, an experimental setup which is intended to verify the analysis in a quantative way is presented.
Experimental Study of the Swirling Flow in the Volute of a Centrifugal Pump
Authors: Elholm T. , Ayder E. , Van Den Braembussche R. 
Published: March 2015

The detailed three-dimensional velocity distributions, corresponding to design and off-design operation, were measured in two different circumferential cross sections of a volute by means of LDV. It is shown that the swirl has a forced vortex type velocity distribution and that the location of the swirl center is changing with mass flow. The through flow velocity distribution is primarily defined by the conservation of angular momentum. A strong interaction between the through flow and swirl velocity is observed.
Flow visualisation in the tongue region reveals a reversal of the velocity at the volute inlet with increasing mass flow. The pressure drop between volute outlet and inlet at low mass flow pushes extra fluid through the tongue gap and increases the mass flow in the volute. The abrupt pressure rise at high mass flow results in local return flow perturbing the flow in the outlet pipe.
Turbulent Combustion Properties Behind a Confined Conical Stabilizer
Authors: Pan J. C. , Schmoll W. J. , Ballal D. R. 
Published: March 2015

Turbulence properties were investigated in and around the recirculation zone produced by a 45° conical flame stabilizer of 25% blockage ratio confined in a pipe supplied with a turbulent premixed methane-air mixture at a Reynolds number of 5.7 × 104. A three-component LDA system was used for measuring mean velocities, turbulence intensities, Reynolds stresses, skewness, kurtosis, and turbulent kinetic energy.
It was found that wall confinement elongates the recirculation zone by accelerating the flow and narrows it by preventing mean streamline curvature. For confined flames, turbulence production is mainly due to shear stress-mean strain interaction. In the region of maximum recirculation zone width and around the stagnation point, the outer stretched flame resembles a normal mixing layer and gradient-diffusion closure for velocity holds. However, and in the absence of turbulent heat flux data, counter-gradient diffusion cannot be ruled out. Finally, and because of the suppression of mean streamline curvature by confinement, in combusting flow, the production of turbulence is only up to 33% of its damping due to dilatation and dissipation.
Acoustic Design of Lightweight Gas Turbine Enclosures
Authors: Rawlinson R. D. 
Published: March 2015

Acoustic enclosures for the gas turbine industry have to comply with a number of stringent safety requirements including structural strength, fire resistance and sound insulation. This has led traditionally to heavy enclosure designs.
Corrugated enclosure panels offer significant structural advantages because of their increased bending stiffness. Consequently, a corrugated panel of a given thickness can give the same structural strength as a flat panel of substantially greater weight and thickness. But corrugated panels are intrinsically less effective as a sound insulator than flat panels of the same thickness.
This paper examines the implications of corrugated, lightweight panels for acoustic enclosures. It illustrated that, by careful design, the inherent acoustical disadvantages of corrugated panels can be overcome so that thinner, lighter and more cost-effective enclosures can be used without compromising the overall structural and acoustical design requirements.
Announcing the LM1600 Marine Gas Turbine Module
Authors: Beiner Christian , Latterman Ruprecht 
Published: March 2015

Motoren- und Turbinen- Union Friedrichshafen (MTU) and General Electric Marine and Industrial Engines (GE) are cooperating in the development of an LM1600 marine gas turbine propulsion module similar to the GE LM2500 marine module.
The GE LM1600 marine gas turbine is described and an outline of the engine performance characteristics is given.
MTU’s design goals and the respective design approaches of essential sub-systems are presented: General arrangement of the module with the installed gas turbine and exhaust collector, base frame with engine and exhaust collector mounting links, shock mounts, acoustic enclosure and the corresponding internal and external auxiliary systems, e.g., lube-oil storage and conditioning assembly, fuel system, engine cooling system, high-speed coupling shaft and ice condition detection system. The interface requirements for combustion air, cooling air and exhaust stacks as well as the interface for vessel piping and wiring are described.
Finally, some LM1600 ship machinery arrangements for CODOG, CODAG and possibly COGAG propulsion systems in future applications are presented.
Performance Prediction of Subsonic Separated Cascades
Authors: Yazigi N. , Charlier M. H. , Gerolymos G. A. , Chauvin J. 
Published: March 2015

During the design process of fans and compressors, rapid computation of performance characteristics at various operating points is essential. In view of estimating off-design performance, the prediction of compressible separated flow is needed.
A method has been developed for predicting such flows in 2-D cascades, with varying blade-height, based on an iterative viscous-inviscid interaction approach. Inviscid flow is simulated using a panel method. The effects of compressibility and streamsheet convergence or divergence are taken into account by singularities distributed in the interior of the flowfield.
Viscous flow is simulated using an integral boundary-layer method, till the point of separation. Laminar and transitory separation bubbles are modelled semi-empirically. Separated-flow regions are simulated using a free streamline model.
The method has been systematically compared with available experimental data and has shown very good agreement concerning the prediction of pressure distribution, deviation angle and loss coefficient, from negative to positive stall and for a wide range of Reynolds number and subsonic Mach number. The method is an interesting performance analysis tool due to its rapidity and reliability.
A Study of Isothermal Flow Past a Confined Bluff Body
Authors: Lai M. K. Y. , D’Souza M. V. , Campbell I. G. , Smallwood G. J. , Snelling D. R. 
Published: March 2015

The paper describes a preliminary assessment of a TEACH-based mathematical model, known as TURCOM, for isothermal flow past a confined bluff-body. The assessment is based on comparisons of numerical predictions with the experimental data. Laser Doppler Velocimetry (LDV) and gas analysis were used to measure radial profiles of axial velocity and CO2 concentration. Laser sheet illumination was employed to study the gross features of the flow.
Depending on the jet velocity ratio, two or three recirculation zones and two well-defined stagnation points along the centerline were predicted. Agreement between the predictions and experimental data were reasonably good, but the axial location of the fuel stagnation point was under-estimated when compared with the LDV data. Flow visualization indicated vortex shedding off the edges of the bluff body, an unsteady flow phenomenon that neither TURCOM prediction nor LDV measurements could identify.
Flow Behavior in a Dump Diffuser With Distorted Flow at the Inlet
Authors: Honami Shinji , Morioka Tadashi 
Published: March 2015

The cold flow experiments are made in a two-dimensional dump diffuser. Behavior of an impinging jet over a flame dome head and its reattachment to the casing wall is presented, when a symmetric or distorted flow is provided at the diffuser inlet. A hot-wire anemometer and laser doppler velocimeter are used. Diffuser performances of the pressure recovery and total pressure loss on three types of pre-diffuser geometry and four cases of dump gap between pre-diffuser exit and flame dome head are tested.
Both pre-diffuser geometry and dump gap are dominant parameters affecting pressure recovery and total pressure loss. A small dump gap causes insufficient pressure recovery in the pre-diffuser, resulting in a loss of total pressure in the diffuser. Distribution of the flow rate to the branched channels is relatively insensitive to the inlet velocity profile with distortion, as the shift of the jet stream occurs just upstream of the flame dome head.
Model Adjustment of Small Rotors for High Speed Gas Turbines
Authors: Delbez Alain , Beth Christian , Gay Daniel 
Published: March 2015

In this paper, we present the studies which are carried out at MICROTURBO relating to rotor-bearing systems mounted in small high speed gas turbines.
These studies are based on both theoretical and experimental approaches, and are aimed at providing an improved prediction of the dynamic behaviour of rotors at the design stage, in particular the critical angular velocities and sensitivity to unbalance.
Prediction and Measurement of Film Cooling Effectiveness for a First-Stage Turbine Vane Shroud
Authors: Granser D. , Schulenberg T. 
Published: March 2015

After compressor discharge air has initially been used to cool the heat shields of the hot gas inlet casing, it can subsequently be employed for film cooling of the first-stage vane shrouds. Since the flow field near these shrouds is three-dimensional, the film cooling effectiveness cannot be predicted correctly by common two-dimensional codes. The secondary flow transports the film from the pressure side to the suction side where it can even climb up the airfoil to cool its trailing section.
Such film cooling effectiveness was first investigated experimentally in a linear vane cascade at atmospheric pressure. The temperatures and static pressure levels at the adiabatic shrouds, as well as the temperature measurements within the vane cascade, are reported for different cooling film blowing rates.
In addition, the secondary flow was analysed numerically using a partially-parabolic computer code for 3D viscous flows. It involves mutual interaction of the boundary layer with the mainstream. The secondary flow can also be modelled with this algorithm, which requires less numerical effort than solving the fully 3D elliptic flow equations. The numerical results of the experiment and numerical predictions are compared. In addition, the application of these results to a high-temperature gas turbine is presented.
A Study on the Blade Shape Influence on Flow Distribution and Performance in Centrifugal Compressor Rotors
Authors: Tuccillo Raffaele , Senatore Adolfo 
Published: March 2015

The authors present an analysis of the flow through a centrifugal compressor rotor. A quasi-3D flow model evaluates the interaction of the meridional and blade-to-blade solution, so as to determine the flow pattern inside an inviscid region.
A further interaction is then considered between the non-viscous flow and the boundary layers which grow along the end-walls and the blade surfaces. This makes it possible both to determine a more realistic flow condition, because of the blockage effects exerted by the boundary layers, and to estimate the total pressure losses related to the momentum thickness.
Examples are presented for a compressor of an aircraft engine. The influence of blade shape on the above described phenomena is analyzed, starting from the actual rotor geometry and making a parametric study of the alterations in flow pattern produced by changes in meridional blade shape, inlet and outlet flow areas, and splitter blades.
The analysis will provide a basis for future activities involving the use of optimizing techniques for the final choice of the blade characteristics.