Amgad Elansary

The control of axial stresses and liquid pressure surges in pipes is an important problem in the design of hydraulic pipe networks. The method of characteristics has been used to solve the transient stresses and pressures in liquid-filled piping systems. Friction is included in the equation of motion. The HZim pressure and maximum stress at any point along the length of the pipe are evaluated for the entire simulation tine. A nonlinear search technique has been developed using the simplex method. The optimal valve closure is sought, that will minimize the maximum pressure and/or stresses. A continuous optimal valve closure policy is specified using spline functions. Numerical examples are presented showing the reduction of the dynamic stress and the dynamic pressure from linear valve closure to optimal valve closure.

The control of stresses and liquid pressure surges in pipes is an important problem in the design of hydraulic pipe networks. The method of characteristics has been used to solve the transient stresses and pressures in liquid-filled piping systems. The friction force is included in the equation of motion for the fluid and the pipe wall. The maximum pressure and maximum stress at any point along the length of the pipe are evaluated for the entire simulation time. The Von Mises criterion is used for the stress calculation. A nonlinear search technique has been developed using the simplex method. The optimal valve closure is sought, that will minimize the maximum pressure and/or stresses. A continuous optimal valve closure policy is specified using spline functions. Numerical examples are presented showing the reduction of the dynamic stress and the dynamic pressure from linear valve closure to optimal valve closure.

The control of stresses and liquid pressure surges in pipes is an important problem in the design of hydraulic pipe networks. The method of characteristics has been used to solve the transient stresses and pressures in liquid-filled piping systems. The friction force is included in the equations of motion for the fluid and the pipe wall. The maximum pressure and maximum stress at any point along the length of the pipe are evaluated for the entire simulation time. A nonlinear search technique has been developed using the simplex method. The optimal valve closure is sought, that will minimize the maximum pressure and/or stresses. A continuous optimal valve closure policy is specified using spline functions. Numerical examples are presented showing the reduction of the dynamic pressure and the dynamic stress from linear valve closure to optimal valve closure for a simple pipeline and a complex pipeline. Also, a method for choosing the shortest time of closure which will keep the stresses below specified allowable stresses is presented.

This paper introduces an approach for solving coupled flow and transports equations in a variable density flow system and presents a numerical model for pollutant transport and flow pattern in layered aquifer system. This formulation is general, flexible and capable of taking full advantage of the nature of flow in such multi-layer systems. Governing equations are discussed for the flow and solute solution with significant variations of density through a porous medium. Equations for mass conservation and solute conversation are formulated in terms of mass fraction hydraulic head and the mass fraction concentrated solute solution. These equations are combined into two nonlinear-coupled partial differential equations. The non-linearity arising from the density variation and from a velocity dependent dispersion tensor made the problem very hard. Therefore, special techniques including mixed interpolation finite …

The fundamental problem addressed during this study lies in the poor quality of surface water in Gharbia Main drain (Kitchener drain). This drain receives agricultural, domestic, industrial, as well as solid wastes from villages and cities located around its path. The main objective of this research is to manage water quality at the drain. The service area of the drain was divided into 6 main basins in order to facilitate the identification of the critical basins along the drain. Water samples were collected from the drain at each basin, and analyzed for different parameters by three different certified laboratories. The parameters included chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP). The concentrations of the selected parameters were also obtained from the literature data. Data analysis was conducted using the box plot tool in order to identify the most reliable data to be used as a benchmark for comparison with the modeling data. A tailored water quality modeling was created using MATLAB to simulate pollutant transport in Gharbia Main drains. Exponential and mass balance equations were used to estimate the targeted water quality parameters along the drain path. Model validation was performed between model estimation and actual data. From an economic point of view, it is recommended to apply the depollution projects in the most critical basins. Thus, a comparison was conducted between the current situation and three proposed scenarios of improving water quality at most critical basins through reducing the load of the domestic wastewater. The model results showed that basins No. 1 …