On the Effectiveness of Aerodynamic Design and Analysis for Centrifugal Compressors

2000 ◽  
Author(s):  
Ronald H. Aungier
Keyword(s):  
Centrifugal Compressor ◽  
Essential Feature ◽  
Industrial Process ◽  
Aerodynamic Design ◽  
Centrifugal Compressors ◽  
Wide Range ◽  
Range Of Functions ◽  
Overall Evaluation ◽  
Analysis System ◽  
Sound Technology

Abstract Effectiveness is promoted as an essential feature of a centrifugal compressor aerodynamic design and analysis system. Effectiveness measures the system’s ability to apply sound technology to the wide range of functions the centrifugal compressor engineer needs to perform to develop, apply and maintain these complex machines. Effectiveness compliments efficiency (or productivity) in the overall evaluation of a design and analysis system. This paper discusses several features that an effective aerodynamic design and analysis system should have to support the design and application of industrial process centrifugal compressors. These features are known to be occasionally (if not often) neglected. Yet they all can be incorporated using technology available from the open literature.

On the Combined Effect on Operating Range of Adjustable IGVs and Variable Speed in Process Multistage Centrifugal Compressors

2013 ◽  
Author(s):  
Alberto Scotti Del Greco ◽  
Libero Tapinassi
Keyword(s):  
Centrifugal Compressor ◽  
Control Device ◽  
Variable Speed ◽  
Centrifugal Compressors ◽  
Speed Regulation ◽  
General Rules ◽  
Wide Range ◽  
Successful Control ◽  
Mach Numbers ◽  
Multistage Centrifugal Compressor

Adjustable inlet guide vanes (IGVs) and variable speed drivers are known as providing process compressors with an effective regulation all throughout the operating envelope of the machine. A large number of works exists in literature reporting the successful control of multistage centrifugal compressors by means of IGVs or speed separately, while a few studies document the combined use of both devices and their effect on compressor performance. The present paper details the off-design behavior of a multistage centrifugal compressor equipped with both types of control. It is shown that classical IGVs advantage in extending the operating envelope of a fixed speed multistage compressor tends to reduce when speed regulation is active too. In this sense, the average level of peripheral Mach numbers inside the compressor may be interpreted as a sort of threshold, since it deeply affects the stage mismatching at off-design conditions. This consideration is corroborated by a number of applications in a wide range of design peripheral Mach numbers. Based on those cases, the paper reviews the general effectiveness of the combined regulation, thus outlining some general rules of thumb for the choice of the optimal control device for a multistage centrifugal compressor.

Centrifugal compressor design

1998 ◽  
Vol 213 (2) ◽  
pp. 139-155 ◽  
Author(s):  
P. M. Came ◽  
C. J. Robinson
Keyword(s):  
Centrifugal Compressor ◽  
State Of The Art ◽  
Mechanical Design ◽  
Preliminary Design ◽  
Aerodynamic Design ◽  
Design Procedures ◽  
Wide Range ◽  
Compressor Design ◽  
Computational Fluid Dynamics Cfd ◽  
Physical Phenomena

Centrifugal compressors are used in a wide range of applications in which performance and mechanical integrity are invariably among the paramount design objectives. There is therefore continuing interest in the development of a sound understanding of the relevant physical phenomena and in the systematic application of the knowledge base that is the forerunner of the established design procedures. The paper reviews centrifugal compressor design methods that are commonly used in industry and reviews the underlying engineering science supporting the design practices. The design process, starting with the preliminary design and its reliance on empirical rules through to state-of-the-art aerodynamic design using computational fluid dynamics (CFD), is presented. The essentials of impeller mechanical design are also included in the paper.

On the Combined Effect on Operating Range of Adjustable Inlet Guide Vanes and Variable Speed in Process Multistage Centrifugal Compressors

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Alberto Scotti Del Greco ◽  
Libero Tapinassi
Keyword(s):  
Centrifugal Compressor ◽  
Control Device ◽  
Variable Speed ◽  
Centrifugal Compressors ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Speed Regulation ◽  
Wide Range ◽  
Mach Numbers ◽  
Multistage Centrifugal Compressor

Adjustable inlet guide vanes (IGVs) and variable speed drivers are known as providing process compressors with an effective regulation all throughout the operating envelope of the machine. A large amount of work exists in literature reporting the successful control of multistage centrifugal compressors by means of IGVs or speed separately, while a few studies document the combined use of both devices and their effect on compressor performance. The present paper details the off-design behavior of a multistage centrifugal compressor equipped with both types of control. It is shown that classical IGVs' advantage in extending the operating envelope of a fixed speed multistage compressor tends to reduce when speed regulation is active too. In this sense, the average level of peripheral Mach numbers inside the compressor may be interpreted as a sort of threshold since it deeply affects the stage mismatching at off-design conditions. This consideration is corroborated by a number of applications in a wide range of design peripheral Mach numbers. Based on those cases, the paper reviews the general effectiveness of the combined regulation, thus outlining some general rules of thumb for the choice of the optimal control device for a multistage centrifugal compressor.

Short Films from a Small Nation

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
Public Information ◽  
Industrial Process ◽  
Actor Network Theory ◽  
Documentary Films ◽  
Wide Range ◽  
Short Films ◽  
Post War ◽  
The 1960S ◽  
Art And Architecture

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.

Structure, Function and Interactions of Tau: Particular Focus on Potential Drug Targets for the Treatment of Tauopathies

2018 ◽  
Vol 17 (5) ◽  
pp. 325-337 ◽  
Author(s):  
Hojjat Borna ◽  
Kasim Assadoulahei ◽  
Gholamhossein Riazi ◽  
Asghar Beigi Harchegani ◽  
Alireza Shahriary
Keyword(s):  
Tau Protein ◽  
Drug Targets ◽  
Brain Injuries ◽  
Potential Drug ◽  
Microtubule Network ◽  
Wide Range ◽  
Potential Risk Factors ◽  
Range Of Functions ◽  
Potential Drug Targets

Background & Objective: Neurodegenrative diseases are among the most widespread lifethreatening disorders around the world in elderly ages. The common feature of a group of neurodegenerative disorders, called tauopathies, is an accumulation of microtubule associated protein tau inside the neurons. The exact mechanism underlying tauopathies is not well-understood but several factors such as traumatic brain injuries and genetics are considered as potential risk factors. Although tau protein is well-known for its key role in stabilizing and organization of axonal microtubule network, it bears a broad range of functions including DNA protection and participation in signaling pathways. Moreover, the flexible unfolded structure of tau facilitates modification of tau by a wide range of intracellular enzymes which in turn broadens tau function and interaction spectrum. The distinctive properties of tau protein concomitant with the crucial role of tau interaction partners in the progression of neurodegeneration suggest tau and its binding partners as potential drug targets for the treatment of neurodegenerative diseases. Conclusion: This review aims to give a detailed description of structure, functions and interactions of tau protein in order to provide insight into potential therapeutic targets for treatment of tauopathies.

scholarly journals High-resolution particle separation by inertial focusing in high aspect ratio curved microfluidics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javier Cruz ◽  
Klas Hjort
Keyword(s):  
High Resolution ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Biological Fluids ◽  
Essential Feature ◽  
Particle Separation ◽  
Size Difference ◽  
Inertial Focusing ◽  
Complex Samples ◽  
Wide Range

AbstractThe ability to focus, separate and concentrate specific targets in a fluid is essential for the analysis of complex samples such as biological fluids, where a myriad of different particles may be present. Inertial focusing is a very promising technology for such tasks, and specially a recently presented variant, inertial focusing in High Aspect Ratio Curved systems (HARC systems), where the systems are easily engineered and focus the targets together in a stable position over a wide range of particle sizes and flow rates. However, although convenient for laser interrogation and concentration, by focusing all particles together, HARC systems lose an essential feature of inertial focusing: the possibility of particle separation by size. Within this work, we report that HARC systems not only do have the capacity to separate particles but can do so with extremely high resolution, which we demonstrate for particles with a size difference down to 80 nm. In addition to the concept for particle separation, a model considering the main flow, the secondary flow and a simplified expression for the lift force in HARC microchannels was developed and proven accurate for the prediction of the performance of the systems. The concept was also demonstrated experimentally with three different sub-micron particles (0.79, 0.92 and 1.0 µm in diameter) in silicon-glass microchannels, where the resolution in the separation could be modulated by the radius of the channel. With the capacity to focus sub-micron particles and to separate them with high resolution, we believe that inertial focusing in HARC systems is a technology with the potential to facilitate the analysis of complex fluid samples containing bioparticles like bacteria, viruses or eukaryotic organelles.

scholarly journals Role of Thioredoxin-Interacting Protein in Diseases and Its Therapeutic Outlook

2021 ◽  
Vol 22 (5) ◽  
pp. 2754
Author(s):  
Naila Qayyum ◽  
Muhammad Haseeb ◽  
Moon Suk Kim ◽  
Sangdun Choi
Keyword(s):  
Interacting Protein ◽  
Thioredoxin Interacting Protein ◽  
Signaling Complex ◽  
Current Review ◽  
Wide Range ◽  
Range Of Functions ◽  
Species Production ◽  
And Oxidative Stress ◽  
Significant Attention

Thioredoxin-interacting protein (TXNIP), widely known as thioredoxin-binding protein 2 (TBP2), is a major binding mediator in the thioredoxin (TXN) antioxidant system, which involves a reduction-oxidation (redox) signaling complex and is pivotal for the pathophysiology of some diseases. TXNIP increases reactive oxygen species production and oxidative stress and thereby contributes to apoptosis. Recent studies indicate an evolving role of TXNIP in the pathogenesis of complex diseases such as metabolic disorders, neurological disorders, and inflammatory illnesses. In addition, TXNIP has gained significant attention due to its wide range of functions in energy metabolism, insulin sensitivity, improved insulin secretion, and also in the regulation of glucose and tumor suppressor activities in various cancers. This review aims to highlight the roles of TXNIP in the field of diabetology, neurodegenerative diseases, and inflammation. TXNIP is found to be a promising novel therapeutic target in the current review, not only in the aforementioned diseases but also in prolonged microvascular and macrovascular diseases. Therefore, TXNIP inhibitors hold promise for preventing the growing incidence of complications in relevant diseases.

scholarly journals Apply IOT technology to practice a pandemic prevention body temperature measurement system: A case study of response measures for COVID-19

2021 ◽  
Vol 17 (5) ◽  
pp. 155014772110181
Author(s):  
Wei-Ling Lin ◽  
Chun-Hung Hsieh ◽  
Tung-Shou Chen ◽  
Jeanne Chen ◽  
Jian-Le Lee ◽  
...  
Keyword(s):  
Body Temperature ◽  
Temperature Measurement ◽  
Measurement System ◽  
Disease Surveillance ◽  
Disease Surveillance System ◽  
Temperature Detection ◽  
Wide Range ◽  
Body Temperature Measurement ◽  
Analysis System ◽  
Temperature Measurement System

Today, the most serious threat to global health is the continuous outbreak of respiratory diseases, which is called Coronavirus Disease 2019 (COVID-19). The outbreak of COVID-19 has brought severe challenges to public health and has attracted great attention from the research and medical communities. Most patients infected with COVID-19 will have fever. Therefore, the monitoring of body temperature has become one of the most important basis for pandemic prevention and testing. Among them, the measurement of body temperature is the most direct through the Forehead Thermometer, but the measurement speed is relatively slow. The cost of fast-checking body temperature measurement equipment, such as infrared body temperature detection and face recognition temperature machine, is too high, and it is difficult to build Disease Surveillance System (DSS). To solve the above-mentioned problems, the Intelligent pandemic prevention Temperature Measurement System (ITMS) and Pandemic Prevention situation Analysis System (PPAS) are proposed in this study. ITMS is used to detect body temperature. However, PPAS uses big data analysis techniques to prevent pandemics. In this study, the campus field is used as an example, in which ITMS and PPAS are used. In the research, Proof of Concept (PoC), Proof of Service (PoS), and Proof of Business (PoB) were carried out for the use of ITMS and PPAS in the campus area. From the verification, it can be seen that ITMS and PPAS can be successfully used in campus fields and are widely recognized by users. Through the verification of this research, it can be determined that ITMS and PPAS are indeed feasible and capable of dissemination. The ITMS and PPAS are expected to give full play to their functions during the spread of pandemics. All in all, the results of this research will provide a wide range of applied thinking for people who are committed to the development of science and technology.

Roles of vanes in diffuser on stability of centrifugal compressor

2019 ◽  
Vol 233 (14) ◽  
pp. 5380-5392
Author(s):  
Wangzhi Zou ◽  
Xiao He ◽  
Wenchao Zhang ◽  
Zitian Niu ◽  
Xinqian Zheng
Keyword(s):  
High Pressure ◽  
Centrifugal Compressor ◽  
Dynamic Pressure ◽  
Pressure Ratio ◽  
Pressure Rise ◽  
Rotating Stall ◽  
Centrifugal Compressors ◽  
Compression System ◽  
The Stability ◽  
Rotating Instability

The stability considerations of centrifugal compressors become increasingly severe with the high pressure ratios, especially in aero-engines. Diffuser is the major subcomponent of centrifugal compressor, and its performance greatly influences the stability of compressor. This paper experimentally investigates the roles of vanes in diffuser on component instability and compression system instability. High pressure ratio centrifugal compressors with and without vanes in diffuser are tested and analyzed. Rig tests are carried out to obtain the compressor performance map. Dynamic pressure measurements and relevant Fourier analysis are performed to identify complex instability phenomena in the time domain and frequency domain, including rotating instability, stall, and surge. For component instability, vanes in diffuser are capable of suppressing the emergence of rotating stall in the diffuser at full speeds, but barely affect the characteristics of rotating instability in the impeller at low and middle speeds. For compression system instability, it is shown that the use of vanes in diffuser can effectively postpone the occurrence of compression system surge at full speeds. According to the experimental results and the one-dimensional flow theory, vanes in diffuser turn the diffuser pressure rise slope more negative and thus improve the stability of compressor stage, which means lower surge mass flow rate.

scholarly journals CFD Study of Nozzle Configurations for Ultra High Bypass Engines

1993 ◽  
Author(s):  
H. Zimmermann ◽  
R. Gumucio ◽  
K. Katheder ◽  
A. Jula
Keyword(s):  
Engine Performance ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
Thrust Coefficient ◽  
Optimum Range ◽  
Installation Effects ◽  
Wide Range ◽  
And Performance ◽  
Aircraft Aerodynamics ◽  
Bypass Ratio

Performance and aerodynamic aspects of ultra-high bypass ratio ducted engines have been investigated with an emphasis on nozzle aerodynamics. The interference with aircraft aerodynamics could not be covered. Numerical methods were used for aerodynamic investigations of geometrically different aft end configurations for bypass ratios between 12 and 18, this is the optimum range for long missions which will be important for future civil engine applications. Results are presented for a wide range of operating conditions and effects on engine performance are discussed. The limitations for higher bypass ratios than 12 to 18 do not come from nozzle aerodynamics but from installation effects. It is shown that using CFD and performance calculations an improved aerodynamic design can be achieved. Based on existing correlations, for thrust and mass-flow, or using aerodynamic tailoring by CFD and including performance investigations, it is possible to increase the thrust coefficient up to 1%.

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