Research Paper
Hossein Bonakdari; Gislain Lipeme-Kouyi; Girdhari Lal Asawa
Volume 1, Issue 2 , June 2014, Pages 51-56
Abstract
The developing turbulent flow in an open channel is a complex three-dimensional flow influenced by the secondary currents and free surface effects and is, therefore, not amenable to analytical solution. This paper aims to study the impact of three key hydraulic parameters (relative roughness, the Froude ...
Read More
The developing turbulent flow in an open channel is a complex three-dimensional flow influenced by the secondary currents and free surface effects and is, therefore, not amenable to analytical solution. This paper aims to study the impact of three key hydraulic parameters (relative roughness, the Froude number and the Reynolds number) on the establishment length using computational fluid dynamic (CFD) analysis. CFD analysis is based on the use of the ANSYS-CFX commercial code. The CFD strategy of modelling is validated against experimental velocity distribution in a cross-section and a good agreement is achieved. A dimensionless length is suggested for predicting the length of the developing flow zone for rectangular open channel. A linear relationship has also been developed for assessing the establishment length.
Research Paper
Matthieu Dufresne; José Vazquez
Volume 1, Issue 2 , June 2014, Pages 57-60
Abstract
Long-throated flumes are measurement structures often used in water and wastewater systems to determine the flow discharge. The head-discharge relationship of long-throated flumes is traditionally determined following the critical flow theory and the boundary layer concept. After a review of the traditional ...
Read More
Long-throated flumes are measurement structures often used in water and wastewater systems to determine the flow discharge. The head-discharge relationship of long-throated flumes is traditionally determined following the critical flow theory and the boundary layer concept. After a review of the traditional approach and an analysis of the approximate assumptions of the boundary layer approach, this study revisits the energy loss approach as an alternative to the questionable boundary layer concept for the determination of the discharge in long-throated flumes. Computational fluid dynamics (CFD) is used for determining the kinetic energy correction coefficient and the piezometric energy correction coefficient along the throat of the flume (especially in the critical section); CFD is also used for locating the critical section and determining the energy loss between the measurement section and the critical section. A new method based on the kinetic energy correction coefficient, the piezometric energy correction coefficient and the energy loss between the measurement section and the control section is proposed. A step-by-step procedure is given for the head-discharge calculation. It appears that the proposed alternative is a simple and promising method to accurately determine the discharge coefficient.
Research Paper
Reza Karimi; Ali Akbar Akhtari; Omid Seyedashraf
Volume 1, Issue 2 , June 2014, Pages 61-65
Abstract
Solving a large sparse set of linear equations is of the problems widely seen in every numerical investigation in the entire range of engineering disciplines. Employing a finite element approach in solving partial derivative equations, the resulting stiffness matrices would contain many zero-valued elements. ...
Read More
Solving a large sparse set of linear equations is of the problems widely seen in every numerical investigation in the entire range of engineering disciplines. Employing a finite element approach in solving partial derivative equations, the resulting stiffness matrices would contain many zero-valued elements. Moreover, storing all these sparse matrices in a computer memory would slower the computation process. The objective of this study is to attain insight into Skyline solver in order to store the non-zero valued entries of large linear systems and enhance the calculations. Initially, the Skyline solver is introduced for symmetric or non-symmetric matrices. Accordingly, an implementation of the proposed solver is conducted using various grid form sets and therefore, several stiffness matrices with different sizes to evaluate the solver’s capability in solving equation systems with a variety of dimensions. Comparing the obtained numerical results it was concluded that Skyline algorithm could solve the equation systems tens of times faster than a regular solver; especially in conducting iterative mathematical computations like Saint-Venant Equations.
Research Paper
Ehsan Fadaei Kermani; Gholam Abbas Barani; Mohamad Javad Khanjani
Volume 1, Issue 2 , June 2014, Pages 66-73
Abstract
In this paper, a new framework has been developed for compatibility analysis of predictive climatic variables distribution with reference evapotranspiration (ETo) in probabilistic analysis of water requirement. Initially, measured monthly meteorological data of four cities of Iran including Kerman, Shiraz, ...
Read More
In this paper, a new framework has been developed for compatibility analysis of predictive climatic variables distribution with reference evapotranspiration (ETo) in probabilistic analysis of water requirement. Initially, measured monthly meteorological data of four cities of Iran including Kerman, Shiraz, Ramsar and Babolsar synoptic weather station recorded from 1961 to 2003 were considered based on De Martonne climate classification. Then monthly ETo was calculated using FAO-Penman-Moentith (FAO-PM), and optimum Probability distribution function (PDF) was determined. The Chow method has been used for frequency analysis, and compatibility analysis was implemented on results. Based on the results, the Generalized Pareto (GP) was selected as optimum PDF for ETo. Results showed that the optimum PDF for minimum and maximum temperature, solar radiation and relative humidity is GP which had compatibility with EToPDF. Eventually, obtained results in compatibility analysis framework were confirmed using Correlation analysis. The proposed methodology developed in this research has application capability in probability scheduling of design water requirement, and can be utilized to optimize probability estimate of water requirement.
Research Paper
Abbas Parsaie; Amir Hamzeh Haghiabi
Volume 1, Issue 2 , June 2014, Pages 74-79
Abstract
Allocation and removing of excess water from the irrigation and drainage network is one of the most important activities in the management of these networks. Side weir is one of the most common structures for this purpose. Study on the flow Hydraulic characteristics of this structure included two parts, ...
Read More
Allocation and removing of excess water from the irrigation and drainage network is one of the most important activities in the management of these networks. Side weir is one of the most common structures for this purpose. Study on the flow Hydraulic characteristics of this structure included two parts, defining the water surface profiles and estimating the discharge coefficient. To estimate the discharge coefficient, many ways as experimental formulas and artificial intelligent models are propose. The empirical formula for simplifying in developing process that assume by the authors, contained significant error so using the AI models are inevitable. In this paper, some of the famous empirical formula and AI models such as Multilayer neural network (MLP) and Adaptive Neuro fuzzy inference system (ANFIS) are assessing with a laboratory experiment. Among the experimental formula, Borghei formula is most accurate (R2=0.83) and the performance of the AI model in Training and testing stage is more suitable (R2=0.96).
Research Paper
Amin Hajiahmadi; Mojtaba Saneie; Mehdi Azhdari Moghadam
Volume 1, Issue 2 , June 2014, Pages 80-85
Abstract
In this century due to population growth, the use of river water has become more complicated. Since most rivers pass across loose and erodible areas, they always act as the most important factor of transferring eroded materials from the solid crust of the earth. Vortex basins are among the solutions ...
Read More
In this century due to population growth, the use of river water has become more complicated. Since most rivers pass across loose and erodible areas, they always act as the most important factor of transferring eroded materials from the solid crust of the earth. Vortex basins are among the solutions known for the high-speed separation of solids from liquids (filtration). One of the problems of such basins is the settling of sediments in their floor which necessitates the performance of required investigations and researches in order to present a method to exclude or reduce such sediments. The present research presents and investigates a plan to resolve this problem. This paper proceeds to perform an experimental study on the effect of a group of curvature submerged vanes in different positions at the floor of a vortex settling basin with a 90ᵒ radial section on the efficiency of the basin. The experiments were performed on a physical model with 96 cm height, 206 cm diameter, 10% floor slope, tow discharges of 45 and 37 L/S, and three orifices with 59, 46 and 36 mm diameters. Uniform aggregate (d50=0.22 mm) was applied in experiments. The efficiency of the basin was determined in six different positions of curvature submerged vanes and the values were investigated compared to each other. The results of experiments showed that the efficiency is higher when the vanes are placed more distant from the orifices while changes in orifice diameter and discharge considerably effect on the efficiency.
Research Paper
Seyed Masoud Tayefeh Cheraghali; Amin Sarang; Mohammad Ali Zahed; Hossein Vahidi; Moazameh Akbari
Volume 1, Issue 2 , June 2014, Pages 86-92
Abstract
One of the main problems in the quality control of rivers is the high control cost imposed upon pollutant units. The cooperative policy approach in the treatment process between two or more pollutant units is a new and economic perspective in the environmental management of catchment basins. Origins ...
Read More
One of the main problems in the quality control of rivers is the high control cost imposed upon pollutant units. The cooperative policy approach in the treatment process between two or more pollutant units is a new and economic perspective in the environmental management of catchment basins. Origins of large amounts pollutants which require a high cost to control pollution are trying to start partnerships with smaller units in establishing joint refineries in order to reduce their own and the whole system's costs. In this study, considering the one way direction of the river's water, the Streeter – Phelps equations were used to simulate the river. The Ant Colony Optimization was used as an efficiency model in order to acquire the best scenario of cooperation based on the maximum elimination of pollution and reduction of treatment costs without straying from the river's quality standards. Also the ratio – trade system was used for commercial purposes. After this the cost of the depleting units was split evenly between them using the cooperative game theory. The efficiency of the model was evaluated by qualitative and quantitative analysis of the Zarjub River in Gilan province of Iran. Three main scenarios were taken to mind for cooperative trading to take place. Carrying out the trade – partnership model could play positively large role in sufficing the quality the control of river water.
Research Paper
Masoud Shariati-Rad; Mohsen Irandoust; Farahnaz Niazi
Volume 1, Issue 2 , June 2014, Pages 93-97
Abstract
A simple and rapid spectrophotometric method for the determination of nitrite in water and soil preparation samples has been developed. Determination of nitrite is based on diazotization of p-nitro aniline with nitrite and subsequent coupling with 4-amino-3-hydroxynaphthalene-1-sulfonic acid in hydrochloric ...
Read More
A simple and rapid spectrophotometric method for the determination of nitrite in water and soil preparation samples has been developed. Determination of nitrite is based on diazotization of p-nitro aniline with nitrite and subsequent coupling with 4-amino-3-hydroxynaphthalene-1-sulfonic acid in hydrochloric acid. The factors affecting the reaction i.e. concentration of p-nitro aniline, concentration of 4-amino-3-hydroxynaphthalene-1-sulfonic acid and concentration of the hydrochloric acid solution were studied and optimized using central composite design. The analysis of the results of experimental design showed that for obtaining higher signals the values of the above factors should be as 2.0×10-4, 5.0×10-4 and 1.33 M, respectively. The reaction yields a product with an absorption maximum at 302 nm. Beer’s law is obeyed in the range 0.10-2.00 mgL-1 of nitrite. The molar absorptivity of the product was found to be 6.74×104. The method was applied successfully to the determination of nitrite in water and soil samples. Relative standard deviation of the method was below 2%.
