scholarly journals Understanding Water Flows and Air Venting Features of Spillway—A Case Study

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2106
Author(s):  
James Yang ◽  
Penghua Teng ◽  
Qiancheng Xie ◽  
Shicheng Li
Keyword(s):  
Flow Behavior ◽  
Air Flow ◽  
Air Velocity ◽  
Cfd Modelling ◽  
Air Supply ◽  
Physical Model Tests ◽  
The Right ◽  
Simultaneous Discharge ◽  
Bottom Outlets

For safe spillway discharge of floods, attention is paid to the water flow. The resulting air flow inside the facility, an issue of personnel security, is sometimes disregarded. The spillway in question comprises two surface gates and two bottom outlet gates lying right below. Air passages to the outlet gates include an original gallery and a recently constructed vertical shaft. To understand water-air flow behavior, 3D CFD modelling is performed in combination with the physical model tests. The simulations are made with fully opened radial gates and at the full pool water level (FPWL). The results show that the operation of only the bottom outlets leads to an air supply amounting to ~57 m3/s, with the air flow rates 35 and 22 m3/s to the left and right outlets. The air supply to the right outlet comes from both the shaft and the gallery. The averaged air velocity in the shaft and the gallery are approximately 5 and 7 m/s. If only the surface gates are fully open, the water jet impinges upon the canal bottom, which encloses the air space leading to the bottom outlets; the air flow rate fluctuates about zero. If all the four gates are open, the total air demand is limited to ~10 m3/s, which is mainly attributable to the shear action of the meeting jets downstream. The air demand differs significantly among the flow cases. It is not the simultaneous discharge of all openings that results in the largest air demand. The flood release from only the two outlets is the most critical situation for the operation of the facility. The findings should provide reference for spillways with the same or similar layout.

Fluid-Structure Interaction of Ship Painting Workshop under Radiation Heat Transfer Condition

2014 ◽  
Vol 1070-1072 ◽  
pp. 1812-1816
Author(s):  
Shao Wen Shang ◽  
Bing Hong Liu ◽  
Guan Wei Guo
Keyword(s):  
Velocity Distribution ◽  
Radiation Heat Transfer ◽  
Radiation Heating ◽  
Air Velocity ◽  
Transfer Condition ◽  
Air Supply ◽  
Suitable Temperature ◽  
Cfd Method ◽  
The Right

Ship coating should be at the right temperature and good ventilated environment. Setting reasonable hang radiant panel for the ship spraying workshop, in the form of radiation heating combined with mechanical air supply to achieve suitable temperature and wind speed. Using the CFD method, by the STAR-CCM+ software, we can simulate the radiation heating workshop space and solid piece. It is concluded that the surrounding air velocity distribution, and observe the change of the temperature field, getting the suitable temperature and air velocity distribution for ship hull surface spraying. Then it can improve the quality of coating.

scholarly journals Influence of Ambient Air Velocity Orientation in Thermal Behaviour of Open Refrigerated Display Cabinets

2010 ◽  
Author(s):  
Pedro Dinis Gaspar ◽  
L. C. Carrilho Gonc¸alves ◽  
Xiao Ge
Keyword(s):  
Thermal Behaviour ◽  
Air Temperature ◽  
Thermal Performance ◽  
Air Flow ◽  
Experimental Tests ◽  
Ambient Air ◽  
Air Velocity ◽  
Cfd Modelling ◽  
Air Curtain ◽  
Numerical Predictions

Open refrigerated display cabinets (ORDCs) suffer alterations of their thermal behaviour and of its performance due to variations of ambient air conditions (air temperature, relative humidity and velocity magnitude and orientation). Some factors interfere and affect the re-circulated air curtain behaviour and thus the equipment’s overall thermal performance. Examples of these factors are the location of air conditioning system discharge grilles, air mass flows originated by pressure differences due to openings to surroundings, and ambient air flow instabilities due to consumers’ passage nearby the frontal opening of the display cabinet, among others. This work performs a three-dimensional (3D) Computational Fluid Dynamics (CFD) modelling of air flow and heat transfer in an ORDC. The influence of ambient air velocity orientation in performance of the re-circulated air curtain is evaluated. A CFD parametric study is developed considering the ambient air orientation parallel, oblique and perpendicular to the frontal opening plane of the equipment. The 3D effects of ambient air velocity orientation are determined through the analysis of air temperature and velocity inside the equipment as well as along and across the air curtain. The longitudinal air flow oscillations and length extremity effects are analyzed, having a considerable influence in the overall thermal performance of the equipment. Experimental tests following EN-ISO Standard 23953 were conducted for climatic class n.er 3 (Tamb = 25 °C, φamb = 60%) in order to characterize the phenomena near inlets, outlets and physical borders. Moreover, experimental data is used to prescribe boundary conditions as well as to validate numerical predictions of temperature and velocity distributions.

URBAN FACADE GEOMETRY ON OUTDOOR COMFORT CONDITIONS: A REVIEW

2020 ◽  
Vol 4 (1) ◽  
pp. 45
Author(s):  
Elahe Mirabi ◽  
Nasrollahi Nazanin
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Natural Ventilation ◽  
Flow Behavior ◽  
Air Flow ◽  
Urban Geometry ◽  
Wide Range ◽  
Low Energy Buildings ◽  
Outdoor Comfort ◽  
Solar Access

<p>Designing urban facades is considered as a major factor influencing issues<br />such as natural ventilation of buildings and urban areas, radiations in the<br />urban canyon for designing low-energy buildings, cooling demand for<br />buildings in urban area, and thermal comfort in urban streets. However, so<br />far, most studies on urban topics have been focused on flat facades<br />without details of urban layouts. Hence, the effect of urban facades with<br />details such as the balcony and corbelling on thermal comfort conditions<br />and air flow behavior are discussed in this literature review. <strong>Aim</strong>: This<br />study was carried out to investigate the effective factors of urban facades,<br />including the effects of building configuration, geometry and urban<br />canyon’s orientation. <strong>Methodology and Results</strong>: According to the results,<br />the air flow behavior is affected by a wide range of factors such as wind<br />conditions, urban geometry and wind direction. Urban façade geometry<br />can change outdoor air flow pattern, thermal comfort and solar access.<br /><strong>Conclusion, significance and impact study</strong>: In particular, the geometry of<br />the facade, such as indentation and protrusion, has a significant effect on<br />the air flow and thermal behavior in urban facades and can enhance<br />outdoor comfort conditions. Also, Alternation in façade geometry can<br />affect pedestrians' comfort and buildings energy demands.</p>

The Calculation of Turbulent Diffusion Coefficients in Aquatic Ecosystems

2019 ◽  
Vol 70 (11) ◽  
pp. 3903-3907
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Transport Equation ◽  
Turbulent Diffusion ◽  
Diffusion Coefficients ◽  
Aquatic Ecosystems ◽  
Specific Area ◽  
Left Bank ◽  
The Right ◽  
Prut River

The paper deals with the issues related to the pollution of aquatic ecosystems. The influence of turbulence on the transport and dispersion of pollutants in the mentioned systems, as well as the calculation of the turbulent diffusion coefficients are studied. A case study on the determination of turbulent diffusion coefficients for some sectors of the Prut River is presented. A new method is proposed for the determination of the turbulent diffusion coefficients in the pollutant transport equation for specific sectors of a river, according to the associated number of P�clet, calculated for each specific area: the left bank, the right bank and the middle of the river.

Traditionalism and politics: A case study of Northern Nigeria

1967 ◽  
Vol 2 (4) ◽  
pp. 509-524 ◽  
Author(s):  
B. J. O. Dudley
Keyword(s):  
Social Change ◽  
Local Government ◽  
Status Quo ◽  
Political Elite ◽  
High Time ◽  
The Political ◽  
Northern Nigeria ◽  
The North ◽  
The Right

In the debate on the Native Authority (Amendment) Law of 1955, the late Premier of the North, Sir Ahmadu Bello, Sardauna of Sokoto, replying to the demand that ‘it is high time in the development of local government systems in this Region that obsolete and undemocratic ways of appointing Emirs’ Councils should close’, commented that ‘the right traditions that we have gone away from are the cutting off of the hands of thieves, and that has caused a lot of thieving in this country. Why should we not be cutting (off) the hands of thieves in order to reduce thieving? That is logical and it is lawful in our tradition and custom here.’ This could be read as a defence against social change, a recrudescence of ‘barbarism’ after the inroads of pax Britannica, and a plea for the retention of the status quo and the entrenched privilege of the political elite.

scholarly journals Fieldwork on epistemic authority markers: What we can learn from different types of data

2020 ◽  
Vol 54 (2) ◽  
pp. 405-445 ◽  
Author(s):  
Karolina Grzech
Keyword(s):  
Data Collection ◽  
Discourse Markers ◽  
Epistemic Modality ◽  
Linguistic Meaning ◽  
Epistemic Authority ◽  
Data Collection And Analysis ◽  
The Right To Know ◽  
Cognitive Study ◽  
The Right

AbstractEpistemicity in language encompasses various kinds of constructions and expressions that have to do with knowledge-related aspects of linguistic meaning (cf. Grzech, Karolina, Eva Schultze-Berndt and Henrik Bergqvist. 2020c. Knowing in interaction: an introduction. Folia Linguistica [this issue]). It includes some well-established categories, such as evidentiality and epistemic modality (Boye, Kasper. 2012. Epistemic meaning: A crosslinguistic and functional-cognitive study. Berlin: De Gruyter Mouton), but also categories that have been less well described to-date. In this paper, I focus on one such category: the marking of epistemic authority, i.e. the encoding of “the right to know or claim” (Stivers, Tanya, Lorenza Mondada & Jakob Steensig. 2011b. Knowledge, morality and affiliation in social interaction. In Stivers et al. 2011a). I explore how the marking of epistemic authority can be documented and analysed in the context of linguistic fieldwork. The discussion is based on a case study of Upper Napo Kichwa, a Quechuan language spoken in the Ecuadorian Amazon that exhibits a rich paradigm of epistemic discourse markers, encoding meanings related to epistemic authority and distribution of knowledge between discourse participants. I describe and appraise the methodology for epistemic fieldwork used in the Upper Napo Kichwa documentation and description project. I give a detailed account of the different tools and methods of data collection, showing their strengths and weaknesses. I also discuss the decisions made at the different stages of the project and their implications for data collection and analysis. In discussing these issues, I extrapolate from the case study, proposing practical solutions for fieldwork-based research on epistemic markers.

Unemployment in the Affective Economy: Exploring the Affective Governing of Young Unemployed People in the Danish Welfare State

2020 ◽  
Vol 66 (3) ◽  
pp. 335-361
Author(s):  
Sabina Pultz
Keyword(s):  
Welfare State ◽  
Complex Relationship ◽  
Field Observations ◽  
Unemployed People ◽  
Political Implications ◽  
Governmentality Studies ◽  
The Right ◽  
The Unemployed ◽  
The Ideal

Abstract This case study investigates the affective governing of young unemployed people, and it concludes that getting money in the Danish welfare state comes with an “affective price”. In the quest for a job, unemployed people have been increasingly responsibilized in order to live up to the ideal of the active jobseeker. Consequently, when faced with unemployment, they are encouraged to work harder on themselves and their motivation. Based on an interview study with young unemployed people (N=39) and field observations made at employment fund agencies in Denmark (2014–15), I explore how young unemployed people are governed by and through their emotions. By supplementing governmentality studies (Foucault et al. 1988, 2010) with the concept of “affective economy” from Ahmed (2014), I discuss how young unemployed people who receive money from the Danish state are placed in a situation of debt. The paper unfolds how this debt becomes visible as the unemployed people often describe feeling under suspicion for not doing enough, for not being motivated enough. Through an abundance of (pro) activity, they have to prove the suspicion of being lazy wrong, and through managing themselves as active jobseekers, they earn the right to get money from the state. Here motivation, passion and empowerment are key currencies. I discuss the intricate interplay between monetary and affective currencies as well as political implications in the context of the Danish welfare. The article contributes by making visible the importance of taking affective matters into account when investigating the complex relationship between politics and psychology.

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