A Direct Performance Comparison of Vaned and Vaneless Stators for Radial Turbines

2006 ◽  
Vol 129 (1) ◽  
pp. 53-61 ◽  
Author(s):  
S. W. T. Spence ◽  
R. S. E. Rosborough ◽  
D. Artt ◽  
G. McCullough
Keyword(s):  
Performance Comparison ◽  
Performance Model ◽  
Operating Conditions ◽  
One Dimensional ◽  
Turbine Performance ◽  
Radial Turbine ◽  
Surface Finishes ◽  
The Impact ◽  
Radial Turbines ◽  
Extensive Performance

An extensive performance investigation has been conducted on a radial turbine with three different vaneless volutes and three corresponding vaned stators. Previously published comparisons have been based on turbines with unmatched flow rates, meaning that the impact of stator losses was not isolated from rotor and exit losses. Each vaned stator configuration tested in this investigation matched the flow rate of the corresponding vaneless volute to within 1%. The volutes and the vaned stators were all machined in order to achieve high quality and comparable surface finishes. At all operating conditions, the vaneless volutes were shown to deliver a significant efficiency advantage over the vaned stators. However, the vaneless volute turbines did not demonstrate any greater tolerance for off-design operating conditions than the vaned stator configurations. Full performance data are presented for the six different turbine configurations tested and a one-dimensional turbine performance model is evaluated as a means of predicting and extrapolating turbine performance.

Application of vacuum belt press filters for cane mud filtration and performance comparison with rotary filters

2014 ◽  
pp. 298-301 ◽  
Author(s):  
Arnaud Petit
Keyword(s):  
Electricity Consumption ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Vacuum Filter ◽  
Sugar Mill ◽  
Belt Press ◽  
Vacuum Belt ◽  
And Performance ◽  
Mud Filtration ◽  
The Impact

Bois-Rouge factory, an 8000 t/d cane Reunionese sugarcane mill, has fully equipped its filtration station with vacuum belt press filters since 2010, the first one being installed in 2009. The present study deals with this 3-year experience and discusses operating conditions, electricity consumption, performance and optimisation. The comparison with the more classical rotary drum vacuum filter station of Le Gol sugar mill highlights advantages of vacuum belt press filters: high filtration efficiency, low filter cake mass and sucrose content, low total solids content in filtrate and low power consumption. However, this technology needs a mud conditioning step and requires a large amount of water to improve mud quality, mixing of flocculant and washing of filter belts. The impact on the energy balance of the sugar mill is significant. At Bois-Rouge mill, studies are underway to reduce the water consumption by recycling low d.s. filtrate and by dry cleaning the filter belts.

Performance Modeling of Desiccant Wheels: 1 — Model Development

2008 ◽  
Author(s):  
Chaoqin Zhai ◽  
David H. Archer ◽  
John C. Fischer
Keyword(s):  
Model Development ◽  
Axial Direction ◽  
Performance Model ◽  
Design Parameters ◽  
Residual Water ◽  
One Dimensional ◽  
Operating Variables ◽  
Steady State Operation ◽  
Rotary Speed ◽  
The Impact

This paper presents the development of an equation based model to simulate the combined heat and mass transfer in the desiccant wheels. The performance model is one dimensional in the axial direction. It applies a lumped formulation in the thickness direction of the desiccant and the substrate. The boundary conditions of this problem represent the inlet outside/process and building exhaust/regeneration air conditions as well as the adiabatic condition of the two ends of the desiccant composite. The solutions of this model are iterated until the wheel reaches periodic steady state operation. The modeling results are obtained as the changes of the outside/process and building exhaust/regeneration air conditions along the wheel depth and the wheel rotation. This performance model relates the wheel’s design parameters, such as the wheel dimension, the channel size and the desiccant properties, and the wheel’s operating variables, such as the rotary speed and the regeneration air flowrate, to its operating performance. The impact of some practical issues, such as wheel purge, residual water in the desiccant and the wheel supporting structure, on the wheel performance has also been investigated.

Impact of Operating Conditions and Design Parameters on Gas Turbine Hot Section Creep Life

2010 ◽  
Author(s):  
S. Eshati ◽  
M. F. Abdul Ghafir ◽  
P. Laskaridis ◽  
Y. G. Li
Keyword(s):  
Gas Turbines ◽  
Performance Model ◽  
Operating Conditions ◽  
Creep Model ◽  
Design Parameters ◽  
Gas Temperature ◽  
Creep Life ◽  
Cooling Effectiveness ◽  
Radial Temperature ◽  
The Impact

This paper investigates the relationship between design parameters and creep life consumption of stationary gas turbines using a physics based life model. A representative thermodynamic performance model is used to simulate engine performance. The output from the performance model is used as an input to the physics based model. The model consists of blade sizing model which sizes the HPT blade using the constant nozzle method, mechanical stress model which performs the stress analysis, thermal model which performs thermal analysis by considering the radial distribution of gas temperature, and creep model which using the Larson-miller parameter to calculate the lowest blade creep life. The effect of different parameters including radial temperature distortion factor (RTDF), material properties, cooling effectiveness and turbine entry temperatures (TET) is investigated. The results show that different design parameter combined with a change in operating conditions can significantly affect the creep life of the HPT blade and the location along the span of the blade where the failure could occur. Using lower RTDF the lowest creep life is located at the lower section of the span, whereas at higher RTDF the lowest creep life is located at the upper side of the span. It also shows that at different cooling effectiveness and TET for both materials the lowest blade creep life is located between the mid and the tip of the span. The physics based model was found to be simple and useful tool to investigate the impact of the above parameters on creep life.

Performance Comparison of More Electric Engine Configurations

2008 ◽  
Author(s):  
Antoon Pluijms ◽  
Klaus-Juergen Schmidt ◽  
Karel Stastny ◽  
Borys Chibisov
Keyword(s):  
Steady State ◽  
Short Range ◽  
Business Case ◽  
Performance Comparison ◽  
Performance Model ◽  
Operating Conditions ◽  
Propulsion Performance ◽  
Surge Margin ◽  
Fuel Burn ◽  
Electric Engine

An analytical study was undertaken to investigate the fuel burn potential of More Electric Engine (MEE) configurations using the performance model of a 2-shaft high BPR 20–30 klbf turbofan in revenue service. The 3 following power off-take configurations were compared: an HP-generator, an LP-generator, and a split-power generator (small HP starter/generator and a main LP generator). For this study, because of the small performance differences, high accuracy steady-state and transient performance models must be used. For steady-state operating conditions, the design point was modified and the off-design redline margins were calculated; ground and flight idle settings were adjusted to yield both the lowest possible fuel burn and residual thrust within the surge margin of the compressor, and the resulting short range mission fuel burn was calculated. For transient conditions, the thrust response, as well as both HPC and LPC surge margin lapse during engine acceleration and deceleration, had to maintain those of the baseline engine and fulfill certification requirements. This was achieved by modifying the idle settings and acceleration/deceleration schedules. Subsequently, the resulting short range mission fuel burn was calculated. Lastly, an introduction to the business case is provided with a simple cost-effectiveness calculation. This study was an initial investigation into MEE’s that focused primarily on the propulsion unit. For further in-depth studies, it is recommended to consider in detail the business model, aircraft weight issues, and the interaction propulsion performance and aircraft performance.

scholarly journals Radial turbine sound and noise characterisation with acoustic transfer matrices by means of fast one-dimensional models

2019 ◽  
pp. 146808741988942
Author(s):  
Antonio Torregrosa ◽  
Luis Miguel García-Cuevas ◽  
Lukas Benjamin Inhestern ◽  
Pablo Soler
Keyword(s):  
Mean Value ◽  
Operating Conditions ◽  
Design Stage ◽  
Transfer Matrices ◽  
Efficient Manner ◽  
One Dimensional ◽  
Engine Design ◽  
Lookup Tables ◽  
Single Entry ◽  
Radial Turbines

Estimating correctly the turbine acoustics can be valuable during the engine design stage; in fact, it can lead to a more optimised design of the silencer and aftertreatment, as well as to better prediction of the scavenging effects. However, obtaining the sound and noise emissions of radial turbocharger turbines with low computational costs can be challenging. To consider these effects in a time-efficient manner, the acoustic response of single-entry radial turbines can be characterised by means of acoustic transfer matrices that change with the operating conditions. Exploiting the different time-scales of the acoustic phenomena and the change in the operating point of the turbine, lookup tables of acoustic transfer matrices can be computed. Then, the obtained characterisation can be used in mean-value engine models. This article presents a method for generating these lookup tables by means of fast one-dimensional simulations of thoroughly validated fidelity, in terms of both acoustics and extrapolation capabilities. Due to the inherent behaviour of radial turbines, the number of computations needed to fill the lookup tables is relatively small, so the method can be used as a simple preprocessing phase before mean-value simulation campaigns.

scholarly journals Industrial Gas Turbine Performance: Compressor Fouling and On-Line Washing

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Uyioghosa Igie ◽  
Pericles Pilidis ◽  
Dimitrios Fouflias ◽  
Kenneth Ramsden ◽  
Panagiotis Laskaridis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Operating Conditions ◽  
Compressor Cascade ◽  
Compressor Blades ◽  
Turbine Performance ◽  
Industrial Gas Turbines ◽  
On Line ◽  
The Impact

Industrial gas turbines are susceptible to compressor fouling, which is the deposition and accretion of airborne particles or contaminants on the compressor blades. This paper demonstrates the blade aerodynamic effects of fouling through experimental compressor cascade tests and the accompanied engine performance degradation using turbomatch, an in-house gas turbine performance software. Similarly, on-line compressor washing is implemented taking into account typical operating conditions comparable with industry high pressure washing. The fouling study shows the changes in the individual stage maps of the compressor in this condition, the impact of degradation during part-load, influence of control variables, and the identification of key parameters to ascertain fouling levels. Applying demineralized water for 10 min, with a liquid-to-air ratio of 0.2%, the aerodynamic performance of the blade is shown to improve, however most of the cleaning effect occurred in the first 5 min. The most effectively washed part of the blade was the pressure side, in which most of the particles deposited during the accelerated fouling. The simulation of fouled and washed engine conditions indicates 30% recovery of the lost power due to washing.

Investigation on the Degree of Reaction in Twin Scroll Radial Turbines at Different Operating Conditions for Turbocharging Applications

2019 ◽  
Author(s):  
Carlo Cravero ◽  
Davide De Domenico ◽  
Andrea Ottonello
Keyword(s):  
High Performance ◽  
Mean Value ◽  
Operating Conditions ◽  
Axial Thrust ◽  
Degree Of Reaction ◽  
Radial Turbine ◽  
Wide Range ◽  
Partial Admission ◽  
Rotor Losses ◽  
Radial Turbines

Abstract Frequently in turbocharging radial turbine studies, some assumptions have to be done in order to make 1D matching calculations as easy as possible and to develop simulation approaches that can be useful for different purposes, like axial thrust prediction. One of these assumptions concerns the degree of reaction, which is often considered constant and equal to the value 0.5. In standard radial turbines design the velocity triangles are set by the target to keep a mean degree of reaction of 50%, in order to obtain low rotor losses and to minimize the exit swirl to get lower losses in the exhaust diffuser. From the experience gained on radial turbines operating in a wide range of conditions, it is evident that: the degree of reaction presents large variations along a given isospeed (especially at low rotational speed) and the mean value is far from 0.5 (particularly true in high performance applications). In the present work a method for the representation of the degree of reaction for radial turbine is suggested. The approach has been developed onto a twin scroll radial turbine for turbocharging, considering a large dataset of operating conditions (at both equal and partial admission). The discussion and the method suggested are based on a rich database from experimental data and numerical simulations developed by the authors on the 3D configuration of the turbines under investigation.

Investigation of a Novel Turbine Housing to Produce a Non-Uniform Spanwise Flow Field at the Inlet to a Mixed Flow Turbine and Provide Variable Geometry Capabilities

2021 ◽  
Author(s):  
Richard Morrison ◽  
Charles Stuart ◽  
Sung In Kim ◽  
Stephen Spence ◽  
Andre Starke ◽  
...  
Keyword(s):  
Flow Separation ◽  
Incidence Angle ◽  
Operating Conditions ◽  
Variable Geometry ◽  
The Novel ◽  
Mixed Flow ◽  
Engine Operation ◽  
Turbine Performance ◽  
The Impact ◽  
Spanwise Flow

Abstract Automotive engine downsizing has placed an increased focus on the ability of the turbocharger to provide adequate boost levels across the full engine operating rage. To achieve the desired levels of turbocharger performance the turbine must be capable of operating effectively at the intended design point and also at off-design conditions. Mixed flow turbines (MFTs) provide a potential method to improve performance at off-design conditions and during transient engine operation. A unique feature of a MFT is the spanwise variation of incidence angle at the rotor leading edge. This results in additional flow separation from the blade suction surface near the hub under a wide range of operating conditions. The flow separation generates additional loss and has a detrimental impact on turbine performance. A novel design of turbine volute similar to a conventional twin-entry turbine volute was examined. The novel turbine volutes were designed to produce a spanwise variation in flow conditions at the rotor inlet. The primary objective was to reduce the incidence angle and increase the mass flow rate at the hub side of the passage relative to the shroud side, as it has previously been identified that this can be beneficial for MFT performance. A number of different volute geometries were examined by numerical analysis to determine the impact of key parameters on turbine performance. The results indicated that generating a suitable spanwise flow distribution could produce a moderate improvement in turbine efficiency at off-design operating conditions. The novel volute design also provided a means of achieving a degree of variable geometry operation to further improve off-design performance. Turbine performance was examined under the variable geometry operation and an improvement in turbine power output at low speed, off-design conditions was achieved. This was analogous to operating with a conventional pivoting vane variable geometry system and had the potential to benefit performance during transient engine operation.

Nonlinear Multiple Points Gas Turbine Off-Design Performance Adaptation Using a Genetic Algorithm

2011 ◽  
Vol 133 (7) ◽  
Author(s):  
Y. G. Li ◽  
M. F. Abdul Ghafir ◽  
L. Wang ◽  
R. Singh ◽  
K. Huang ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Gas Turbine ◽  
Scaling Factor ◽  
Performance Model ◽  
Operating Conditions ◽  
Performance Models ◽  
Design Performance ◽  
Turbine Performance ◽  
Thermodynamic Performance ◽  
Performance Adaptation

Accurate gas turbine performance models are crucial in many gas turbine performance analysis and gas path diagnostic applications. With current thermodynamic performance modeling techniques, the accuracy of gas turbine performance models at off-design conditions is determined by engine component characteristic maps obtained in rig tests and these maps may not be available to gas turbine users or may not be accurate for individual engines. In this paper, a nonlinear multiple point performance adaptation approach using a genetic algorithm is introduced with the aim to improve the performance prediction accuracy of gas turbine engines at different off-design conditions by calibrating the engine performance models against available test data. Such calibration is carried out with introduced nonlinear map scaling factor functions by “modifying” initially implemented component characteristic maps in the gas turbine thermodynamic performance models. A genetic algorithm is used to search for an optimal set of nonlinear scaling factor functions for the maps via an objective function that measures the difference between the simulated and actual gas path measurements. The developed off-design performance adaptation approach has been applied to a model single spool turbo-shaft aero gas turbine engine and has demonstrated a significant improvement in the performance model accuracy at off-design operating conditions.

Aerodynamic Investigation of a Nozzle Clearance Effect on Radial Turbine Performance

2012 ◽  
Author(s):  
M. Roumeas ◽  
S. Cros
Keyword(s):  
Blade Angle ◽  
Axial Fan ◽  
Flow Angle ◽  
Turbine Performance ◽  
Radial Turbine ◽  
The One ◽  
Cooling Air ◽  
The Impact ◽  
Aerodynamic Investigation ◽  
Nozzle Blade

Liebherr Aerospace designs and develops cooling air systems, with notably axial fan and radial turbine or compressor. The development of new architectures (especially electrical system) now requires improving the turbine performances on the whole operating range. To reach that industrial request, a variable nozzle area can be used, performed by changing the nozzle blade angle for a given blade height. For the blades to be moveable, tip and hub clearances must be present (and thus modeled) in the nozzle. The impact of that clearance on the turbine performance, and moreover on the flow field, is studied here by 3D numerical way. The clearance mass flow leads to the development of a marginal vortex along the nozzle blade chord that tends to increase the total pressure loss in the nozzle on the one hand, and to modify the flow angle on the rotor inlet on the other hand. The vortex development induces an efficiency loss that must be taken into account during the design.

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