Evaluation and determination of subsurface drainage spacing in two steady and unsteady flow conditions with closure of the impermeable layer to the ground surface. case study: Markazi province, Iran *

2020 ◽  
Vol 69 (4) ◽  
pp. 756-775
Author(s):  
Behzad Moshayedi ◽  
Mohsen Najarchi ◽  
Mohammad Mahdi Najafizadeh ◽  
Shahab Khaghani
Keyword(s):  
Unsteady Flow ◽  
Ground Surface ◽  
Subsurface Drainage ◽  
Flow Conditions ◽  
Impermeable Layer

Determination of head losses in a surge chamber: Robert Bourassa power plant case study

2007 ◽  
Vol 34 (9) ◽  
pp. 1038-1047 ◽  
Author(s):  
Musandji Fuamba ◽  
Gilles Brosseau ◽  
Éric Mainville
Keyword(s):  
Power Plant ◽  
Three Dimensional ◽  
Hydraulic Head ◽  
Transportation Systems ◽  
Flow Conditions ◽  
Flow Models ◽  
Head Losses ◽  
Water Transportation

Optimal management of power plant units is achieved when the global efficiency of the units and the minimization of the total hydraulic head losses through the water transportation systems can be combined. Evaluating these hydraulic head losses appears to be very difficult due to the complexity of the flow conditions through the hydraulic structures. A hydraulic energy based method to determine head losses in the surge chamber has been proposed in this paper, as well as a method to manage the opening of units which would optimize the production of electricity. This method was applied to a case study, and successful results have been obtained showing how the head loss varies in the surge chamber.Key words: hydraulic head losses, power plant unit, surge chamber, unit efficiency, three-dimensional flow conditions, turbulent flow models, computational fluid dynamics.

scholarly journals Pemodelan Keruntuhan Bendungan Menggunakan HEC-RAS 2D Studi Kasus Bendungan Gondang, Kabupaten Karanganyar

Rekayasa ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 205-211
Author(s):  
Kiki Marina Murdiani ◽  
Sri Sangkawati ◽  
Kresno Wikan Sadono
Keyword(s):  
Unsteady Flow ◽  
Action Plan ◽  
Dam Failure ◽  
Flow Conditions ◽  
Area At Risk ◽  
Failure Modeling ◽  
Central Java ◽  
The Government ◽  
The Village

Pembangunan bendungan memberikan manfaat untuk masyarakat sekitar waduk, namun juga menyimpan bahaya jika mengalami keruntuhan bendungan. Salah satu syarat yang harus dipenuhi sebelum mendapatkan sertifikat ijin operasi adalah RTD (Rencana Tindak Darurat). Manfaat dari disusunnya rencana tindak darurat adalah untuk pedoman para pengelola bendungan maupun pemerintah yang berada pada daerah yang terkena resiko apabila terjadi kondisi darurat pada Bendungan. Makalah ini mencakup daerah yang terdampak jika terjadi kegagalan bendungan. Pemanfaatan Software menggunakan HEC-RAS dengan studi kasus Bendungan Gondang yang berlokasi di Kabupaten Karanganyar. Lokasi terdampak menurut hasil analisis adalah Desa Gempolan, Desa Ganten, Desa Kwadungan, Desa Kutho, Kecamatan Kerjo, Kabupaten Karanganyar, Provinsi Jawa Tengah. Bendungan ini mempunyai tampungan total 9,15 juta meter kubik dengan tinggi bendungan 71 meter.  Pemodelan keruntuhan bendungan dengan 2D pada kondisi unsteady flow, simulasi keruntuhan akibat piping tengah pada elevasi +495 m. Hasil pemodelan keruntuhan Bendungan Gondang yang akan menimbulkan dampak paling besar jika terjadi piping tengah akibat banjir PMF dengan puncak debit Qoutflow= 902,40m3/det. Kecepatan banjir akibat keruntuhan bendungan tercepat yang sampai ke pemukiman adalah 24 menit yaitu sampai di Desa Gempolan yang berjarak 0,6 km dari lokasi bendungan.AbstractThe construction of a dam provides benefits to the community around the reservoir, but also saves danger if it experiences dam collapse. One of the requirements that must be met before obtaining an operating permit certificate is the RTD (Emergency Action Plan). The benefit of formulating an emergency action plan is to guide the dam managers and the government who are in the area at risk if an emergency condition occurs at the Dam. This paper covers the area affected in the event of dam failure. Utilization of Software uses HEC-RAS with a Gondang Dam case study located in Karanganyar Regency. The affected locations, according to the results of the analysis are Gempolan Village, Ganten Village, Kwadungan Village, Kutho Village, Kerjo District, Karanganyar Regency, Central Java Province. This Dam has a total reservoir of 9.15 million cubic meters with a dam height of 71 meters. Dam failure modeling with 2D under unsteady flow conditions, simulation of collapse due to middle piping at +495 m elevation. The results of the Gondang Dam collapse modeling, which will have the most significant impact if there is middle piping due to PMF flooding with peak discharge Qoutflow = 902.40m3 / sec. The speed of flooding due to the collapse of the Dam that reached the fastest settlement was 24 minutes, namely to the village of Gempolan, which is 0.6 km from the location of the Dam.Keywords: Gondang Dam, dam break, affected area Karanganyar.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

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.

Is Hydraulics Over-Used or Under-Used in Storm Drainage?

1994 ◽  
Vol 29 (1-2) ◽  
pp. 53-61
Author(s):  
Ben Chie Yen
Keyword(s):  
Unsteady Flow ◽  
Computational Time ◽  
Time Step ◽  
Flow Routing ◽  
Kinematic Wave Equation ◽  
Storm Drainage ◽  
Saint Venant Equations ◽  
Unsteady Flow Routing ◽  
Selection Of

Urban drainage models utilize hydraulics of different levels. Developing or selecting a model appropriate to a particular project is not an easy task. Not knowing the hydraulic principles and numerical techniques used in an existing model, users often misuse and abuse the model. Hydraulically, the use of the Saint-Venant equations is not always necessary. In many cases the kinematic wave equation is inadequate because of the backwater effect, whereas in designing sewers, often Manning's formula is adequate. The flow travel time provides a guide in selecting the computational time step At, which in turn, together with flow unsteadiness, helps in the selection of steady or unsteady flow routing. Often the noninertia model is the appropriate model for unsteady flow routing, whereas delivery curves are very useful for stepwise steady nonuniform flow routing and for determination of channel capacity.

scholarly journals Investigations on historical monuments’ deterioration through chemical and isotopic analyses: an Italian case study

2021 ◽  
Author(s):  
Maria Ricciardi ◽  
Concetta Pironti ◽  
Oriana Motta ◽  
Rosa Fiorillo ◽  
Federica Camin ◽  
...  
Keyword(s):  
Potassium Nitrate ◽  
Sewage Water ◽  
X Ray Diffraction ◽  
Italian Case ◽  
Historical Monuments ◽  
Isotopic Analyses ◽  
Historic Centre ◽  
The Church

AbstractIn this paper, we analysed the efflorescences present in the frescos of a monumental complex named S. Pietro a Corte situated in the historic centre of Salerno (Campania, Italy). The groundwater of the historic centre is fed by two important streams (the Rafastia and the Fusandola) that can be the sources of water penetration. The aims of this work are to (i) identify the stream that reaches the ancient frigidarium of S. Pietro a Corte and (ii) characterize the efflorescences on damaged frescos in terms of chemical nature and sources. In order to accomplish the first aim, the water of the Rafastia river (7 samples) and the water of the Fusandola river (7 samples) were analysed and compared with the water of a well of the Church (7 samples). The ionic chromatography measurements on the water samples allowed us to identify the Rafastia as the river that feeds the ancient frigidarium of S. Pietro a Corte. To investigate the nature and the origin of the efflorescences (our second aim), anionic chromatography analyses, X-ray diffraction measurements, and the isotopic determination of nitrogen were performed on the efflorescences (9 samples) and the salts recovered from the well (6 samples). Results of these analyses show that efflorescences are mainly made of potassium nitrate with a δ15N value of + 9.3 ± 0.2‰. Consequently, a plausible explanation for their formation could be the permeation of sewage water on the walls of the monumental complex.

Influence of climate change on low flow conditions. Case study: Laborec River, eastern Slovakia

2021 ◽  
Author(s):  
Katarzyna Kubiak-Wójcicka ◽  
Martina Zeleňáková ◽  
Peter Blištan ◽  
Dorota Simonová ◽  
Agnieszka Pilarska
Keyword(s):  
Climate Change ◽  
Low Flow ◽  
Flow Conditions
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