International Journal of Engineering
Volume:25 Issue: 1, Jan 2012

Establishment of rating curves are often required by the hydrologists for flow estimates in the streams, rivers etc. Measurement of discharge in a river is a time-consuming, expensive, and difficult process and the conventional approach of regression analysis of stage-discharge relation does not provide encouraging results especially during the floods. P.

In a competitive market, customer decision is made to maximize his utility. It can be assumed that risk of losing a supply chain’s customer can be defined based on products utility from customer point of view. This paper takes account of product price and service level as competition criteria. The proposed model is based on non-cooperative game theory, for one-manufacturer and one-retailer supply chain facing an outside integrated-competitor. The aim of the research is to investigate the trade-offs of responsiveness and efficiency in a supply chain. Therefore, we consider product utility from customer point of view as an objective along with traditional profit objective function. Three scenarios are proposed in the paper: competition based on profit gained, competition based on responsiveness to customer needs, and finally, competition based on the profit gained and responsiveness to customer needs, concurrently. Numerical examples are presented including sensitivity analysis of key parameters. We illustrate that the relative importance that player considers for profit compared to the risk of losing customer has a critical role in supply chain prosperity.

In this research UF cheese pricing is considered and Pegah, Pak, Kaleh, Rouzaneh and Mihan firms’ data, as five main UF cheese competitive firms of Iran in breakfast cheese competitive market, is used. By using these firm’s sales data, production data and price of each ton of UF cheese in nineteen work-periods (each work-period is 6 months), their sales equations are estimated for each work-period. With the objective of minimizing the difference between each firm’s sales in each work-period and each firm’s target sales in the same work-period, optimal prices are calculated in 4 states: static games with complete information, dynamic games with complete information with one leader and four followers that decide simultaneously, dynamic games with complete information with one leader and four followers that decide simultaneously considering that Rouzaneh and Mihan firms collude in their product pricing, dynamic games with complete information with one leader and four followers considering that followers collude in their product pricing.

In this study a Modified Compressible Smoothed Particle Hydrodynamics (MCSPH) method is introduced which is applicable in problems involve shock wave structures and elastic-plastic deformations of solids. As a matter of fact, algorithm of the method is based on an approach which descritizes the momentum equation into three parts and solves each part separately and calculates their effects on the velocity field and displacement of particles. The most exclusive feature of the method is exactly removing artificial viscosity of the formulations and representing good compatibility with other reasonable numerical methods without any rigorous numerical fractures or tensile instabilities while MCSPH dose not use any extra modifications. Two types of problems involve elastic-plastic deformations and shock waves are presented here to demonstrate the abilities of MCSPH in simulation of such problems and its capability of shock capturing. The problems that are proposed here are low and high velocity impacts between aluminum projectiles and semi infinite aluminum beams. Elastic-perfectly plastic model is chosen for constitutive model of the aluminum and the results of simulations are compared with other reasonable studies in these cases.

this paper a novel homotopy perturbation method has been presented for forced convection boundary layer problems in a porous medium. Noting the infinite condition, a homotopy form which is similar to the singular perturbation form has been considered. The inner and outer solutions have been achieved and the coincidence of the results has been investigated with a proper matching method. The results have been compared with the results of other researchers in the field of mixed convection boundary layer problem in porous media. The comparison shows that this method can be used properly for analyzing of similar problems.

The present study deals the theoretical modeling aspects of coupled conductive and radiative heat transfer in the presence of absorbing, emitting and scattering gray medium within two-dimensional square furnace including two flames. The gray radiative medium is bounded by isothermal walls which are considered to be opaque, diffuse and gray. The well known discrete ordinate method (DOM) is employed to solve the radiative transfer equation (RTE) to obtain the radiative intensity distribution in the participating medium which is considered to be the hot exhaust gases from two burners. In order to compute the temperature field inside the medium, the gas energy equation including the conductive and radiative term is solved by finite difference method. By this technique, the effect of radiation conduction parameter, which has a main role on thermal behavior of the conduction-radiation systems are throughoutly explored. Comparison between the present numerical results with theoretical results by other investigators shows a good consistency.

Control of a fluid velocity profile by injection and suction of non-ionized flow in presence of a uniform steady magnetic field has important technical applications. In this paper, the unsteady incompressible and viscous conducting fluid flow has been investigated in a circular channel. The channel wall has been assumed to be non-conducting and porous. It has been subjected to a uniform steady magnetic field which is vertical to the axis of channel and suction and injection are applied at the wall. The well known equations of MHD have been governed to the motion of an electrically conducting fluid that has been subjected to magnetic field. The numerical solution has been carried out by finite difference approach. By continuum considering of the fluid, it has been seen that the velocity profiles varies because of additional flow injection and suction. The mentioned profile has some difference with non-injection and suction conditions. So that, the results of present numerical simulation shown that the flow injection and suction through the wall can be controlled effectively, the main flow in channel. This phenomenon has engineering importance in some of industrial application. The results have been obtained for different injected and sucked non-ionized flow rate. Finally, comparison of the present result with the finite element method results had shown the good agreement.

Three-dimensional simulations of the single-phase laminar flow and forced convective heat transfer of water in microchannels with small rectangular sections having specific hydraulic diameters and distinct geometric configurations were investigated numerically. The numerical results indicated that the laminar heat transfer was to be dependent upon the aspect ratio and the ratio of the hydraulic diameter to the center to center distance of the microchannels. The geometries and operating conditions of that indicated microchannel were created using a finite volume-based computational fluid dynamics technique. The aims of this paper were to obtain computational Nusselt number in laminar flow by a numerical method and validate it with available experimental studies. The results in this numerical method were in a good agreement with experimental results within an error in acceptable range. After that, at each Z-location conceivable temperature profiles and pressure drops were obtained for each simulation and for each Reynolds number related pressure drops were explored. Finally, the effects of the geometric parameters on the average Nusselt number in the laminar flow were illustrated numerically.

In this paper, buckling behavior of moderately thick functionally graded rectangular plates resting on elastic foundation subjected to linearly varying in-plane loading is investigated. The neutral surface position for a functionally graded plate which its material properties vary in the thickness direction is determined. Based on the first-order shear deformation plate theory and the neutral surface concept, the equilibrium and stability equations are derived. An analytical approach is employed to decouple the stability equations, as these equations are converted into two decoupled equations. Employing Levy-type solution, the buckling equation is reduced to an ordinary differential equation with variable coefficients and solved exactly using power series method of Frobenius. To examine accuracy of the present formulation and procedure, several convergence and comparison studies are investigated. Furthermore, the effects of different parameters of plate and elastic foundation on the critical buckling load of functionally graded rectangular plate are discussed.