Performance analysis of an NxN ATM switch with Markov Modulated Poisson Process under Back-pressure mechanism

In this paper, we present a performance study of an input/output buffered type ATM switch with backpressure mechanism with a MMPP process as input. The backpressure is exerted at the Head of Line (HOL) level to prevent output buffer cell loss fig1 (a)(b). MMPP process is chosen due to its bursty nature able to capture multimedia source characteristics such as data and voice. We propose an approximate method to calculate the total waiting time in the switch. Numerical examples will be given for two states MMPP to quantitatively show the effects of output buffer size b on performance switch. Using structured stochastic matrices of M/G/1 type does the analysis and the obtained results extend those related to scalar case (Poisson process).Voir le lien ic

Phenomenological modeling and intensification of texturing/grinding-assisted solvent oil extraction: case of date seeds (Phoenix dactylifera L.)

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Numerical Study of Lid-Driven Hybrid Nanofluid Flow in a Corrugated Porous Cavity in the Presence of Magnetic Field

The lid-driven top wall’s influence combined with the side walls’ waviness map induce the mixed convection heat transfer, flow behavior, and entropy generation of a hybrid nanofluid (Fe3O4–MWCNT/water), a process analyzed through the present study. The working fluid occupies a permeable cubic chamber and is subjected to a magnetic field. The governing equations are solved by employing the GFEM method. The results show that the magnetic force significantly affects the working fluid’s thermal and flow behavior, where the magnetic force’s perpendicular direction remarkably improves the thermal distribution at Re = 500. Also, increasing Ha and decreasing Re drops both the irreversibility and the heat transfer rate. In addition, the highest undulation number on the wavy-sided walls gives the best heat transfer rate and the highest irreversibility

Entropy Generation in 2D Lid-Driven Porous Container with the Presence of Obstacles of Different Shapes and under the Influences of Buoyancy and Lorentz Forces

This paper includes a numerical investigation of a hybrid fluid containing 4% of Al2O3-Cu nanoparticles in a lid-driven container. The upper wall of the container has a high temperature and is movable. The lower wall is cool and wavy. An obstacle is set in the middle of the container for its effect on thermal activity. The medium is permeable to the fluid, and the entire system is immersed in a fixed-effect magnetic field. The digital simulation is achieved using the technique of Galerkin finite element (GFEM) which solves the differential equations. This investigation aims to know the pattern of heat transfer between the lateral walls and the lower wall of the container through the intervention of a set of conditions and criteria, namely: the strength of the magnetic field changes in the range of (Ha = 0 to 100); the chamber porosity varies in the range of (Da = 10−5 to 10−2); the strength of buoyancy force is varied according to the Grashof number (Gr = 102 to 104); the cross-section of the baffle includes the following shapes—elliptical, square, triangular and circular; the surface of the lower wall contains waves; and the number changes (N = 2 to 8). Through this research, it was concluded that the triangular shape of the baffle is the best in terms of thermal activity. Also, increasing the number of lower-wall waves reduces thermal activity. For example, the change in the shape of the obstacle from the elliptical to triangular raises the value of Nu number at a rate of 15.54% for Ha = 0, N = 8, and Gr = 104