a brass vortex tube (vt) with interchangeable parts is used to determine the optimum cold end orifice diameter, main tube length and diameter. experiments were carried out to study the effects of operating pressure as well. it is shown that there is an optimum value for cold end orifice diameter, which is equal to 4mm and there is an optimum value for cold and hot exit temperature difference at...

End pumped or longitudinally pumped solid-state lasers have proven to be very efficient sources. They differ from side pumped lasers, regardless of the nature of the pump, by the fact that the gain is concentrated in a very well defined region. Furthermore the gain exhibits a transverse profile directly related to the pump beam profile which induces new requirements on the relative sizes of the...

Due to increasing the number of decision-making criteria in today's ever complicated geometrical optimization problems, the traditional multiobjective optimization approaches, whether a priori, a posteriori or interactive's, found to be insufficient and ineffective. In this paper the drawbacks of the current algorithms are reviewed and the urgent need for inserting a learning componen...

The standard geometrical shape optimization method proceed by the application of successive diffeomorphisms close to the identity starting from an initial guessed shape. Consequently, it does not allow for the optimization of the topology which is kept unchanged from one iteration to the other. The topological gradient enables to determine if the inclusion of a small hole of given shape is cost...

Abstract In this paper, multi-objective optimization (MOO) of Al2O3-water nanofluid flow in microchannel heat sinks (MCHS) with triangular ribs is performed using Computational Fluid Dynamics (CFD) techniques and Non-dominated Sorting Genetic Algorithms (NSGA II). At first, nanofluid flow is solved numerically in various MCHS with triangular ribs using CFD techniques. Finally, the CFD data will...

In recent years, the importance of economical considerations in the field of dam engineering has motivated many researchers to propose new methods for minimizing the cost of dames and in particular arch dams. This paper presents a method for shape optimization of double curvature arch dams corresponding to minimum construction cost while satisfying different constraints such as natural frequenc...

a new method of optimization on linear parabolic solar collectors using exergy analysis is presented. a comprehensive mathematical modeling of thermal and optical performance is simulated and geometrical and thermodynamic parameters were assumed as optimization variables. by applying a derived expression for exergy efficiency, exergy losses were generated and the optimum design and operating co...

This article presents a constrained optimization method, based on the duality theory, which does not need the gradients. The method is used to optimize superconducting devices. In order to reduce the computing effort, the initial optimization problem is divided into two coupled optimization problems. One manages the geometrical parameters, the other finds the best current densities for a given ...