scholarly journals Performance Prediction and Geometry Optimization for Application of Pump as Turbine: A Review

2022 ◽  
Vol 9 ◽  
Author(s):  
Ming Liu ◽  
Lei Tan ◽  
Shuliang Cao
Keyword(s):  
Performance Prediction ◽  
Rural Areas ◽  
Guide Vane ◽  
Geometry Optimization ◽  
Prediction Methods ◽  
Prediction Errors ◽  
Polynomial Fitting ◽  
Specific Speed ◽  
Loss Modeling ◽  
The One

Pump as Turbine (PAT) is a technically and economically effective technology to utilize small/mini/micro/pico hydropower, especially in rural areas. There are two main subjects that influence the selection and application of PAT. On the one hand, manufacturers of pumps will not provide their characteristics under the turbine mode, which requires performance prediction methods. On the other hand, PAT efficiency is always slightly lower than that of pump, which requires further geometry optimization. This literature review summarized published research studies related to performance prediction and geometry optimization, aimed at guiding for selection and optimization of PAT. Currently, there exist four categories of performance prediction methods, namely, using BEP (Best Efficiency Point), using specific speed, loss modeling, and polynomial fitting. The using BEP and loss modeling methods are based on theoretical analysis, while using specific speed and polynomial fitting methods require statistical fitting. The prediction errors of published methods are within ±10% mostly. For geometry optimization, investigations mainly focus on impeller diameter and blade geometry. The influence of impeller trimming, blade rounding, blade wrap angle, blade profile, blade number, blade trailing edge position, and guide vane number has been studied. Among published methods, the blade rounding and forward-curved impellers are the most effective and feasible techniques.

scholarly journals Slip Factor Correction in 1-D Performance Prediction Model for PaTs

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 565 ◽  
Author(s):  
Tommaso Capurso ◽  
Michele Stefanizzi ◽  
Giuseppe Pascazio ◽  
Sergio Ranaldo ◽  
Sergio Camporeale ◽  
...  
Keyword(s):  
Prediction Model ◽  
Performance Prediction ◽  
Distribution Systems ◽  
Water Distribution ◽  
Fluid Dynamic ◽  
Outlet Section ◽  
Prediction Errors ◽  
Slip Factor ◽  
Specific Speed ◽  
Slip Phenomenon

In recent years, pumps operated as turbines (PaTs) have been gaining the interest of industry and academia. For instance, PaTs can be effectively used in micro hydropower plants (MHP) and water distribution systems (WDS). Therefore, further efforts are necessary to investigate their fluid dynamic behavior. Compared to conventional turbines, a lower number of blades is employed in PaTs, lowering their capability to correctly guide the flow, hence reducing the Euler’s work; thus, the slip phenomenon cannot be neglected at the outlet section of the runner. In the first part of the paper, the slip phenomenon is numerically investigated on a simplified geometry, evidencing the dependency of the lack in guiding the flow on the number of blades. Then, a commercial double suction centrifugal pump, characterized by the same specific speed, is considered, evaluating the dependency of the slip on the flow rate. In the last part, a slip factor correlation is introduced based on those CFD simulations. It is shown how the inclusion of this parameter in a 1-D performance prediction model allows us to reduce the performance prediction errors with respect to experiments on a pump with a similar specific speed by 5.5% at design point, compared to no slip model, and by 8% at part-loads, rather than using Busemann and Stodola formulas.

First Principles Investigation of the Stability and the Chemical Behavior of Hydrogen in ThCoH4

2011 ◽  
Vol 66 (3) ◽  
pp. 269-274
Author(s):  
Samir F. Matar
Keyword(s):  
Negative Charge ◽  
Geometry Optimization ◽  
Full Geometry Optimization ◽  
Intermetallic Matrix ◽  
Charge Analysis ◽  
The Stability ◽  
The One ◽  
Site Selective ◽  
Bader Charge Analysis ◽  
Positively Charged

We address the changes in the electronic structure brought by the insertion of hydrogen into ThCo leading to the experimentally observed ThCoH4. Full geometry optimization positions the hydrogen in three sites stabilized in the expanded intermetallic matrix. From a Bader charge analysis, hydrogen is found to be in a narrow iono-covalent (~−0.6) to covalent (~−0.3) bonding which should enable site-selective desorption. The overall chemical picture shows a positively charged Thδ+ with the negative charge redistributed over a complex anion {CoH4}δ− with δ~1.8. Nevertheless this charge transfer remains far from the one in the more ionic hydridocobaltate anion CoH54− in Mg2CoH5, due to the largely electropositive character of Mg.

scholarly journals The role of SMEs in innovation-oriented economic development

2017 ◽  
pp. 95-99
Author(s):  
Tamás Köpeczi-Bócz ◽  
Mónika Lőrincz
Keyword(s):  
Rural Areas ◽  
Tertiary Education ◽  
National Level ◽  
Business Environment ◽  
The Other ◽  
Sectoral Structure ◽  
Other Hand ◽  
Knowledge Intensive ◽  
The One

Both at European and national level tertiary and quaternary sectors are concentrated in the metropolitan centre. In the rural areas only the sites of such sectors can be found the premises of which temporarily transform the sectoral structure of these areas, but from the regional development aspect they did not prove to be an effective strategy.The European Commission is now focusing on growth from innovation, which could become the driving force behind productivity growth and the economy’s long-term trend. The innovation-oriented economic development’s key players are on the one hand the knowledge-intensive enterprises, on the other hand the universities. Tertiary education can play a role – among others – in shaping and creating the development of knowledge intensive business environment and conditions, on the other hand it can assist the development of network contacts – another precondition of employment growth.

scholarly journals DISTÂNCIA DA REDE ELÉTRICA QUE VIABILIZA O USO DE MOTORES DIESEL EM ÁREAS IRRIGADAS DO BRASIL

Irriga ◽  
2007 ◽  
Vol 12 (2) ◽  
pp. 263-272 ◽  
Author(s):  
Rodrigo Otávio Câmara Monteiro ◽  
Priscylla Ferraz ◽  
Rubens Duarte Coelho ◽  
Ronaldo Antônio do Santos
Keyword(s):  
Electric Power ◽  
Rural Areas ◽  
Electrical Power ◽  
Electric Energy ◽  
Power Lines ◽  
Electric Motors ◽  
Irrigation Systems ◽  
Diesel Motors ◽  
The One ◽  
Agricultural Areas

DISTÂNCIA DA REDE ELÉTRICA QUE VIABILIZA O USO DE MOTORES DIESEL EM ÁREAS IRRIGADAS DO BRASIL  Rodrigo Otávio Câmara Monteiro; Priscylla Ferraz; Rubens Duarte Coelho; Ronaldo Antônio do SantosEscola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Piracicaba, SP [email protected]  1 RESUMO             Na maioria das regiões do país, a energia elétrica aparece como a alternativa, economicamente mais viável, no acionamento de bombas em áreas irrigadas, o que justifica seu uso por aproximadamente 70% dos irrigantes. No entanto, em determinadas situações, não se dispõe, nas proximidades, de rede elétrica, o que passa a viabilizar o uso de motores diesel. Este trabalho, portanto, propôs a análise dos custos horários de bombeamento com a operação de motores diesel e elétricos nas 5 regiões do Brasil. Considerou-se as composições tarifárias verde, azul e convencional, período de irrigação de 2, 4, 6 e 8 meses por ano e operação no horário de ponta e fora de ponta. Para essa avaliação, foi considerado um motor diesel e elétrico, de potência comercial de 50 cv. O ponto de equilíbrio entre motor elétrico e diesel foi determinado pela distância da rede de energia elétrica até o local de consumo. A viabilidade de utilização dos motores diesel em relação ao acionamento de motores elétricos foi encontrada a partir de distâncias da rede de transmissão elétrica de1,32 a8,71 km, sendo a primeira a condição mais atrativa, encontrada na região Sudeste, com 2 meses/ano de irrigação, na tarifa convencional. UNITERMOS: Energia elétrica, irrigação, custo de bombeamento  MONTEIRO, R. O. C.; FERRAZ, P.; COELHO, R. D.; SANTOS, R.A. do. VIABILITY OF DIESEL MOTOR USE IN IRRIGATED AREAS OF BRAZIL DUE TO DISTANCE FROM ELECTRIC POWER LINES  2 ABSTRACT In most agricultural areas ofBrazil, electric power seems to be the most feasible economic alternate methods for the functioning of pumps in irrigated areas, therefore 70%  of irrigation systems use it. However, the viability of electric power lines is restricted to only one part of rural areas, making it necessary the implementation of diesel engines as a source of electrical power for water management. The aim of this study was to investigate the viability of the use of electric energy and diesel motors.  For this study, an electric motor and a diesel one, both of 50HP potency, were evaluated, taking into consideration the following variables: tax composition, areas of the country and number of operation hours per year. The viability of the diesel engine use in relation to implantation of electric motors was determined from  distances that ranged from1.32 kmup to8.71 kmbetween the consumption place and the electric power lines. The most favorable condition is the one found in  the southeast of the country: 2 irrigation months/year.KEYWORDS: Electric energy, irrigation, pump costs 

Drawing with Performance Prediction

1995 ◽  
Author(s):  
Peter Schwenn ◽  
George Hazen
Keyword(s):  
Design Optimization ◽  
Performance Prediction ◽  
Fold Increase ◽  
Building Blocks ◽  
Programming Environment ◽  
Immediate Feedback ◽  
Surface Stability ◽  
Performance Constraints ◽  
And Performance ◽  
The One

We describe some advances in Performance Prediction Programs - "PPP"1 for sailing yachts2 - primarily integrating PPP analysis into drawing and providing new sculpting operations in which fairness and desired hydrostatic and on her performance determining characteristics are maintained - the shape remains a boat or a ship of the desired kind during reshaping. Our building blocks for such an integration are: a thousand-fold increase in PPP speed3, new editing tools which maintain Boatness4 , and an accessible modularization of the engineering physics of the PPP within a new programming environment which allows immediate changes by designers. Specifically, these new functions are introduced at the boundary of Drawing and the PPP: - A live knotmeter is displayed with each design variant on the drawing boar, - alongside it's antagonist - Rating. - Continuously updated hydrotatics (including the speed determining factors LSM, wetted surface, stability, prismatics, .. ) are displayed with the knotometer, with the 'positive' factors (like length) graphically opposing the 'negative' (like wetted surface.) Dimensions for PPP use are calculated automatically from the shape at hand - in particular: appendage dimensions, hydrostatics, and so forth. - Bounding limits are set for a design optimization by drawing two or more outlier yacht forms. The space in between can be explored by hand or automatically. - Local optimums of Speed against rating are provided as a 'Snap' function. This is the one dimensional version of automatic exploration for optima. - Intermediate shapes are also controlled during design optimization to maintain realism and performance constraints on type, fairness, 'look', speed producing shape measures like prismatic and displacement etc., and even handicap. - Immediate feedback is available if one chooses to exploit the new programming environment to make aero hydro model changes or extensions to the internal PPP mechanisms while drawing and exploring.

Cooperatives as Responsible and Innovative Entrepreneurial Ecosystems in Smart Territories

2017 ◽  
pp. 459-490
Author(s):  
Francisca Castilla-Polo ◽  
Dolores Gallardo-Vázquez ◽  
M. Isabel Sánchez-Hernández ◽  
María del Consuelo Ruiz-Rodríguez
Keyword(s):  
Social Responsibility ◽  
Olive Oil ◽  
Rural Areas ◽  
Business Models ◽  
Social Value ◽  
The Other ◽  
Entrepreneurial Ecosystem ◽  
Entrepreneurial Ecosystems ◽  
The One ◽  
The Relationship

Nowadays, and more than never, businesses´ stakeholders are demanding Social Responsibility (SR) and innovation. In this situation, any business is concerned about how to implement social and innovative practices in creating economic and social value at the same time. This chapter analyzes the relationship between SR and innovation in cooperatives. On the one hand, even acknowledging that the degree of implementation of SR is still different in companies, cooperatives seem to be responsible by nature. However, on the other hand, traditionally innovation has been not a visible strength in the cooperative enterprises. The focus is centered on a specific place: the olive oil cooperatives in the south of Spain and we will describe the cooperative entrepreneurial ecosystem created around this territory, demonstrating how SR and innovation are important features related to competitiveness and success. Cooperatives are strategic business models able to foster development in traditional rural areas, so we can define them as an entrepreneurial ecosystem in smart territories.

Evaluation of supercritical CO2 compressor off-design performance prediction methods

Energy ◽  
2020 ◽  
Vol 213 ◽  
pp. 119071
Author(s):  
Yongju Jeong ◽  
Seongmin Son ◽  
Seong Kuk Cho ◽  
Seungjoon Baik ◽  
Jeong Ik Lee
Keyword(s):  
Performance Prediction ◽  
Supercritical Co2 ◽  
Prediction Methods ◽  
Design Performance

scholarly journals Influence of guide vane clearance on internal flow of medium-specific speed Francis turbine

2019 ◽  
Vol 240 ◽  
pp. 022056
Author(s):  
Gnanasekaran Kishor Kumar ◽  
Tadachika Tanaka ◽  
Naoki Yamaguchi ◽  
Toui Taniwaki ◽  
Kazuyoshi Miyagawa ◽  
...  
Keyword(s):  
Guide Vane ◽  
Internal Flow ◽  
Francis Turbine ◽  
Specific Speed

Airbnb Contribution to Rural Development

2020 ◽  
Vol 11 (2) ◽  
pp. 31-46
Author(s):  
Abbas Strømmen-Bakhtiar ◽  
Evgueni Vinogradov ◽  
Marit Kristin Kvarum ◽  
Kristian Rydland Antonsen
Keyword(s):  
Rural Communities ◽  
Rural Development ◽  
Rural Areas ◽  
Social Life ◽  
Sharing Economy ◽  
Negative Effects ◽  
Urban Bias ◽  
Positive Effects ◽  
Technological Developments ◽  
The One

The technological developments described in terms of industrial revolutions or disruptive innovations have been shaping economic and social life in rural areas. The global trend towards urbanization presents a major challenge to rural communities. The aim of this article is to study how the peer-to-peer economy influences rural municipalities. On the one hand, in the literature, it is argued that sharing economy may improve accessibility, encourage mobility, attract investments and reduce urban bias. On the other hand, both academics and practitioners are aware of the disruptive effects of sharing economy on e.g., local real estate and labor markets. This qualitative study is based on empirical data from a municipality on the Lofoten Islands of Norway. The results demonstrate that Airbnb has some positive and some negative effects on rural development, but the magnitudes of these effects are modest. Of positive effects, the authors can mention increased local tourism, stimulation of conservation/restoration of traditional houses, and increased recreational mobility for rural residents.

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