Performance Improvement of a Mixed Flow Turbine Using 3D Blading

2020 ◽  
Author(s):  
Matthew Elliott ◽  
Stephen Spence ◽  
Martin Seiler ◽  
Marco Geron
Keyword(s):  
Performance Improvement ◽  
Design Feature ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Optimized Design ◽  
Mixed Flow ◽  
Performance Improvements ◽  
Blade Shape ◽  
Real Performance ◽  
A Performance

Abstract Mixed flow turbines have reached a level of maturity where iterative performance improvements are very small, with real performance benefits coming from better matching to a given application as opposed to improvements in technology. One ubiquitous design feature of mixed flow turbines used to control stress within the wheel is the radial fibre constraint, wherein blade material is stacked radially outward along the entirety of the blade. While this constraint yields a mechanical benefit, it constrains the aerodynamic design significantly, with the blade shape defined by one camberline. One potential means of realizing a performance improvement is the use of 3D blading, where the blade is not constrained to a radially fibred structure. In such a design, the blade shape could be freely modified to better control blade loading and secondary flows. This study investigated the viability of such 3D blading through optimization of a state of the art mixed flow turbine. An equivalent design was ensured by maintaining the meridional shape and operating conditions of the baseline wheel, thus facilitating a fair comparison between the radial and 3D wheels. The paper details the optimization including an innovative constraint-driven geometry modification tool, experimental validation of performance predictions, and an investigation into why 3D blading facilitated a performance improvement. The optimization process identified a performance improvement across the entire turbocharger operating line. With performance improvements facilitated through a reduction in tip leakage loss, and improved pressure recovery within the conical diffuser. Importantly, the optimized design met targets for mass flow, maximum stress levels, and modal behaviour, through the use of the novel geometry modification process.

Aeromechanical Optimization of Scalloping in Mixed Flow Turbines

2021 ◽  
Author(s):  
Matthew Elliott ◽  
Stephen Spence ◽  
Martin Seiler ◽  
Marco Geron
Keyword(s):  
Internal Combustion Engines ◽  
Design Guidelines ◽  
Operating Conditions ◽  
Flow Structures ◽  
Optimized Design ◽  
Mixed Flow ◽  
Turbine Wheel ◽  
Engine Load ◽  
Baseline Design ◽  
Turbine Rotors

Abstract Scalloping of radial and mixed flow turbocharger turbine rotors has been commonplace for many years as a means of inertia reduction and stress relief. The interest in turbine rotor inertia reduction is driven by transient loading requirements of turbocharged internal combustion engines, as this is a key factor in the time taken to meet transient engine torque requirements. Due to the high density materials used in turbine rotors, any material removal from the turbine wheel has a significant impact on turbocharger inertia, and thus the transient response of the engine. It is well known that scalloping not only reduces inertia, but also efficiency. This study aimed to identify if it was possible to produce a new scallop design which reduced the scalloping efficiency penalty without increasing inertia, or compromising mechanical constraints. This was carried out with the aim of developing design recommendations for scalloping where a complete minimization of inertia is not the design goal. A multipoint, multi-physics numerical optimization, with constraints on inertia and back disc stress, was carried out to determine what efficiency benefit could be realized by aerodynamically designing mixed flow turbine scalloping. An efficiency benefit was identified across the entire turbocharger operating line, with increased benefit at low engine load, whilst not exceeding the design constraints. Scalloping losses for the baseline design were found to be greatest at low engine load, where the turbine experienced low expansion ratio, mass flow and speed. This explains why an aerodynamic redesign yields the greatest benefit under those operating conditions. These performance predictions were experimentally validated on the cold flow test rig at Queen’s University Belfast, with good agreement between simulated and measured data. To conclude the study, a detailed loss audit was carried out to identify key loss generating flow structures, and to understand how changes in geometry affected the formation and development of these flow structures throughout the passage. A large vortex which entered the passage from the scalloped region and interacted with the tip leakage vortex along the suction surface of the blade was identified as the main source of loss due to scalloping. The optimized design was found to better control the location of entry of this vortex into the blade passage, thus reducing the associated loss, and facilitating a performance improvement. Geometric design guidelines were then proposed based on these findings.

Combination of Turbocharger and Industrial Technologies for the Development of an Improved Mixed-Flow Turbine Design

2021 ◽  
Author(s):  
Holger Franz ◽  
Jens Niewöhner ◽  
Stefan Mühlenbrock
Keyword(s):  
Industrial Applications ◽  
Point Of View ◽  
Operating Conditions ◽  
Mixed Flow ◽  
Operating Range ◽  
Performance Improvements ◽  
Final Design ◽  
Set Up ◽  
Turbine Design ◽  
Parameter Values

Abstract A new mixed-flow radial turbine design for industrial applications was developed and experimentally investigated. The presented mixed-flow turbine recovers energy in industrial processes, which have unused pressurized, hot off-gas available. The design parameter values are very similar to the ones of mixed-flow turbines for turbocharger applications. Consequently, a turbocharger design was used as starting basis. The mechanical requirements of the industrial application are less challenging for the turbine design. It was possible to extend the design space of the blades far beyond the typical radial fiber constraint, which is usually used to fulfill the mechanical restrictions. This gives more freedom for the parameters used in the blade geometry generation. The final design has an increased efficiency and operating range. In addition to a maximized design point efficiency, a wide operating range is one of the major requirements concerning the turbine performance. During the development process of the radial turbine’s wheel, an automated optimization was used. Due to the competitive design targets, multiple objectives and constrains were formulated. To satisfy the off-design efficiency requirements, each geometry was analyzed by means of six operating points. The mechanical integrity was checked by directly coupled FE simulations. The final design is further investigated and the reasons for the gained improvements are discussed. An experimental investigation of a prototype confirmed the numerically predicted improvements. A comparison of the measurements and the numerical results are shown. The objective of the paper is to show the possible potentials in efficiency and operating range of radial turbines with low mechanical restrictions. In many energy recovery applications, the operating conditions are well known and within clearly defined boundaries. For these applications, it is possible to engineer mixed-flow turbines primarily from the aerodynamical point of view ans secondly from the mechanical one. In the following described work, it was possible, starting from a good turbocharger design, to increase the turbine’s performance. An automatic multi-point and multi-physics optimization was set up to reach the performance improvements.

Performance Improvement Through Indexing of Turbine Airfoils: Part 1 — Experimental Investigation

1995 ◽  
Author(s):  
F. W. Huber ◽  
P. D. Johnson ◽  
O. P. Sharma ◽  
J. B. Staubach ◽  
S. W. Gaddis
Keyword(s):  
Performance Improvement ◽  
Space Shuttle ◽  
Computational Procedure ◽  
Analytical Investigation ◽  
Test Facility ◽  
Test Article ◽  
Performance Improvements ◽  
Turbine Stator ◽  
Turbine Performance ◽  
Cfd Analyses

This paper describes the results of a study to determine the performance improvements achievable by circumferentially indexing successive rows of turbine stator airfoils. An experimental / analytical investigation has been completed which indicates significant stage efficiency increases can be attained through application of this airfoil clocking concept. A series of tests was conducted at the National Aeronautics and Space Administration’s (NASA) Marshall Space Flight Center (MSFC) to experimentally investigate stator wake clocking effects on the performance of the Space Shuttle Main Engine Alternate Fuel Turbopump Turbine Test Article. Extensive time-accurate Computational Fluid Dynamics (CFD) simulations have been completed for the test configurations. The CFD results provide insight into the performance improvement mechanism. Part one of this paper describes details of the test facility, rig geometry, instrumentation, and aerodynamic operating parameters. Results of turbine testing at the aerodynamic design point are presented for six circumferential positions of the first stage stator, along with a description of the initial CFD analyses performed for the test article. It should be noted that first vane positions 1 and 6 produced identical first to second vane indexing. Results obtained from off-design testing of the “best” and “worst” stator clocking positions, and testing over a range of Reynolds numbers are also presented. Part two of this paper describes the numerical simulations performed in support of the experimental test program described in part one. Time-accurate Navier-Stokes flow analyses have been completed for the five different turbine stator positions tested. Details of the computational procedure and results are presented. Analysis results include predictions of instantaneous and time-average mid-span airfoil and turbine performance, as well as gas conditions throughout the flow field. An initial understanding of the turbine performance improvement mechanism is described.

Performance Improvements in Cooker-Top Gas Burners for Small Aspect Ratio Changes

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Robson L. Silva ◽  
Bruno V. Sant′Ana ◽  
José R. Patelli ◽  
Marcelo M. Vieira
Keyword(s):  
Energy Conversion ◽  
Fuel Consumption ◽  
Conversion Efficiency ◽  
Minimum Energy ◽  
Energy Conversion Efficiency ◽  
Energy Performance ◽  
Operating Conditions ◽  
Lower Fuel Consumption ◽  
Performance Improvements ◽  
Aspect Ratios

This paper aims to identify performance improvements in cooker-top gas burners for changes in its original geometry, with aspect ratios (ARs) ranging from 0.25 to 0.56 and from 0.28 to 0.64. It operates on liquefied petroleum gas (LPG) and five thermal power (TP) levels. Considering the large number of cooker-top burners currently being used, even slight improvements in thermal performance resulting from a better design and recommended operating condition will lead to a significant reduction of energy consumption and costs. Appropriate instrumentation was used to carry out the measurements and methodology applied was based on regulations from INMETRO (CONPET program for energy conversion efficiency in cook top and kilns), ABNT (Brazilian Technical Standards Normative) and ANP—National Agency of Petroleum, Natural Gas (NG) and Biofuels. The results allow subsidizing recommendations to minimum energy performance standards (MEPS) for residential use, providing also higher energy conversion efficiency and/or lower fuel consumption. Main conclusions are: (i) Smaller aspect ratios result in the same heating capacity and higher efficiency; (ii) higher aspect ratios (original burners) are fuel consuming and inefficient; (iii) operating conditions set on intermediate are lower fuel consumption without significant differences in temperature increases; (iv) Reynolds number lower than 500 provides higher efficiencies.

Supplier performance measurement system use, relationship trust, and performance improvement: a dyadic perspective

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vieri Maestrini ◽  
Andrea Stefano Patrucco ◽  
Davide Luzzini ◽  
Federico Caniato ◽  
Paolo Maccarrone
Keyword(s):  
Performance Measurement ◽  
Performance Improvement ◽  
Measurement System ◽  
Structural Equation ◽  
Performance Measurement System ◽  
Content Type ◽  
Performance Improvements ◽  
Supplier Performance ◽  
Performance Measurement Systems ◽  
The Impact

PurposeGrounding on resource orchestration theory, this paper aims to study the relationship between the way buying companies use their supplier performance measurement systems and the performance improvements obtained from suppliers, with relationship trust identified as a mediator in the previous link.Design/methodology/approachThe authors design a conceptual model and test it through structural equation modelling on a final sample of 147 buyer-supplier responses, collected by means of a dyadic survey.FindingsResults suggest that the buyer company may achieve the most by balancing a diagnostic and interactive use of the measurement system, as they are both positively related to supplier performance improvement. Furthermore, relationship trust acts as a mediator in case of the interactive use, but not for the diagnostic. This type of use negatively affects relationship trust, due to its mechanistic use in the buyer-supplier relationship.Originality/valueThe authors’ results contribute to the current academic debate about supplier performance measurement system design and use by analyzing the impact of different supplier performance measurement system uses, and highlighting their relative impact on relationship trust and supplier performance improvement. From a methodological perspective, adopting a dyadic data collection process increases the robustness of the findings.

Steady State Engine Test Demonstration of Performance Improvement With an Advanced Turbocharger

2013 ◽  
Author(s):  
Harold Sun ◽  
Dave Hanna ◽  
Liangjun Hu ◽  
Eric Curtis ◽  
James Yi ◽  
...  
Keyword(s):  
Steady State ◽  
Performance Improvement ◽  
High Efficiency ◽  
Combustion Engine ◽  
Load Condition ◽  
Department Of Energy ◽  
Speed Ratio ◽  
Mixed Flow ◽  
Turbine Wheel ◽  
Low Speed

Heavy EGR required on diesel engines for future emission regulation compliance has posed a big challenge to conventional turbocharger technology for high efficiency and wide operation range. This study, as part of the U.S. Department of Energy sponsored research program, is focused on advanced turbocharger technologies that can improve turbocharger efficiency on customer driving cycles while extending the operation range significantly, compared to a production turbocharger. The production turbocharger for a medium-duty truck application was selected as a donor turbo. Design optimizations were focused on the compressor impeller and turbine wheel. On the compressor side, advanced impeller design with arbitrary surface can improve the efficiency and surge margin at low end while extending the flow capacity, while a so-called active casing treatment can provide additional operation range extension without compromising compressor efficiency. On the turbine side, mixed flow turbine technology was revisited with renewed interest due to its performance characteristics, i.e. high efficiency at low-speed ratio, relative to the base conventional radial flow turbine, which is relevant to heavy EGR operation for future diesel applications. The engine dynamometer test shows that the advanced turbocharger technology enables over 3% BSFC improvement at part-load as well as full-load condition, in addition to an increase in rated power. The performance improvement demonstrated on engine dynamometer seems to be more than what would typically be translated from the turbocharger flow bench data, indicating that mixed flow turbine may provide additional performance benefits under pulsed exhaust flow on an internal combustion engine and in the low-speed ratio areas that are typically not covered by steady state flow bench tests.

scholarly journals Point-of-Interest Recommender Systems based on Location-Based Social Networks: A Survey from an Experimental Perspective

2022 ◽  
Author(s):  
Pablo Sánchez ◽  
Alejandro Bellogín
Keyword(s):  
Social Networks ◽  
Recommender Systems ◽  
Information Sources ◽  
Learning Approaches ◽  
Performance Improvements ◽  
Point Of Interest ◽  
Real Performance ◽  
Research Questions ◽  
Developing Area ◽  
Location Based Social Networks

Point-of-Interest recommendation is an increasing research and developing area within the widely adopted technologies known as Recommender Systems. Among them, those that exploit information coming from Location-Based Social Networks (LBSNs) are very popular nowadays and could work with different information sources, which pose several challenges and research questions to the community as a whole. We present a systematic review focused on the research done in the last 10 years about this topic. We discuss and categorize the algorithms and evaluation methodologies used in these works and point out the opportunities and challenges that remain open in the field. More specifically, we report the leading recommendation techniques and information sources that have been exploited more often (such as the geographical signal and deep learning approaches) while we also alert about the lack of reproducibility in the field that may hinder real performance improvements.

scholarly journals Computer Data Storage and Management Platform Based on Big Data

2021 ◽  
Vol 2066 (1) ◽  
pp. 012022
Author(s):  
Cheng Luo
Keyword(s):  
Big Data ◽  
Data Management ◽  
Performance Improvement ◽  
Data Storage ◽  
Nonvolatile Memory ◽  
Linear Structure ◽  
Ring Structure ◽  
Computer Data ◽  
Management Platform ◽  
A Performance

Abstract Due to the continuous development of information technology, data has increasingly become the core of the daily operation of enterprises and institutions, the main basis for decision-making development. At the same time, due to the development of network, the storage and management of computer data has attracted more and more attention. Aiming at the common problems of computer data storage and management in practical work, this paper analyzes the object and content of data management, investigates the situation of computer data storage and management in China in recent two years, and interviews and tests the data of programming in this design platform. At the same time, in view of the related problems, the research results are applied to practice. On the basis of big data, the storage and management platform is designed. The research and design adopts a special B+ tree node linear structure of CIRC tree, and the linear node structure is changed into a ring structure, which greatly reduces the number of data persistence instructions and the performance overhead. The results show that compared with the most advanced B+ tree design for nonvolatile memory, crab tree has 3.1 times and 2.5 times performance improvement in reading and writing, respectively. Compared with the previous NV tree designed for nonvolatile memory, it has a performance improvement of 1.5 times, and a performance improvement of 8.4 times compared with the latest fast-fair. In the later stage, the expansion of the platform functions is conducive to the analysis and construction of data related storage and management functions, and further improve the ability of data management.

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