New determination method of the neutron diffraction system resolution at the Algerian Es-Salam research reactor

The aim of this article is to determine the resolution of the neutron diffraction system (NDS) installed around the Algerian Es Salam research reactor. By using a new method based on neutron radiography technique we have measured the beam divergence at the exit of Soller Collimator (α₂) and hence determine effective collimations. The determination of the adequate resolution of our NDS is performed on experimental results obtained from neutron diffraction patterns for different collimation divergences (α₂) and (α₃) values obtained from several apertures sizes (S ₂) and (S ₃).     

Grid solution of problem with unilateral constraints

The present study deals with the solution of a problem, defined in a three-dimensional domain, arising in fluid mechanics. Such problem is modelled with unilateral constraints on the boundary. Then, the problem to solve consists in minimizing a functional in a closed convex set. The characterization of the solution leads to solve a time-dependent variational inequality. An implicit scheme is used for the discretization of the time-dependent part of the operator and so we have to solve a sequence of stationary elliptic problems. For the solution of each stationary problem, an equivalent form of a minimization problem is formulated as the solution of a multivalued equation, obtained by the perturbation of the previous stationary elliptic operator by a diagonal monotone maximal multivalued operator. The spatial discretization of such problem by appropriate scheme leads to the solution of large scale algebraic systems. According to the size of these systems, parallel iterative asynchronous and synchronous methods are carried out on distributed architectures; in the present study, methods without and with overlapping like Schwarz alternating methods are considered. The convergence of the parallel iterative algorithms is analysed by contraction approaches. Finally, the parallel experiments are presented.     

Effect of External Induced Convection on Heat Transfer at Water Boiling

Physics of Atomic Nuclei - In this paper, we experimentally and theoretically study the effect of external induced convection on heat transfer from horizontal heaters under conditions of pool...     

Non isothermal simulation of non-Newtonian flow in the shot sleeve of semi-solid die casting processes

This work present a numerical study of the non isothermal flow of metal in the semi-solid state in the shot sleeve of horizontal die casting machine during the injection process. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Numerical Simulation and analysis of molten flow in the shot sleeve of die casting process

This work presents a numerical study of the flow of molten metal in the shot sleeve of horizontal high-pressure die casting machine during the injection process. The analysis of the wave of the molten metal created by plunger motion can be of help in reducing porosity in manufactured parts caused by air entrapment. The used numerical model, which considers the problem as two-dimensional, is based on the conservation equations of mass and momentum. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)