singular perturbation problems have been studied by many mathematicians. since the approximate solutions of these problems are as the sum of internal solution (boundary layer area) and external ones, the formation or non-formation of boundary layers should be specified. this paper, investigates this issue for a singular perturbation problem including a first order differential equation with gen...

This study develops a fuzzy sliding mode controller (FSMC) based on a variable boundary layer. A fuzzy inference mechanism is used to on-line tune the thickness of the boundary layers of the controller. Minimum rule base has been used for the fuzzy inference system which results in low calculation effort. The aim of this paper is to design a controller which will eliminate the chattering of FSM...

Singular perturbation problems have been studied by many mathematicians. Since the approximate solutions of these problems are as the sum of internal solution (boundary layer area) and external ones, the formation or non-formation of boundary layers should be specified. This paper, investigates this issue for a singular perturbation problem including a first order differential equation with gen...

Earth dams have been used widely recently in flood and sedimentation control projects and feeding ground waters in country's watersheds and correct locating for such structures is necessary for increasing their efficiency. In this work, it is attempted to determine the correct locations for constricting earth dams in Yoosef-abad watershed in Tabas using v and incorporating information layers. T...

We consider the Euler system of compressible and entropic gaz dynamics in a bounded open domain of R with wall boundary condition. We prove the existence and the stability of families of solutions which correspond to a ground state plus a large entropy boundary layer. The ground state is a solution of the Euler system which satisfies some explicit additional conditions on the boundary. These co...

high weissenberg boundary layer flow of viscoelastic fluids on a stretching surface has been studied. the flow is considered to be steady and two dimensional. flows of viscoelastic liquids at high weissenberg number exhibit stress boundary layers near walls. these boundary layers are caused by the memory of the fluid. upon proper scaling and by means of an exact similarity transformation, the n...

in this paper, the accuracy of k- and k- turbulence models in super sonic boundary layer capturing of smooth/rough flat plates have been comprehensively investigated. among these investigations, some sorts of sensitivity analysis, including change in turbulence model, generated-grid density, near wall affects, c magnitude (for boundary layers generated on smooth flat plates), and change in c...