This paper is a numerical work to investigate thermal interactions between heat fluxes generated by electronic devices mounted on a vertical printed circuit board (PCB). In fact, the effect of some parameters such as Grashof number (Gr), the distance (S) between the heat sources and the upper exit distance (Le) was studied. The results show that a regular and uniform heat sources distribution in the inlet is very important in order to take advantage from the leading edge of the boundary layer and to obtain the necessary heat dissipation. The impact of parameters on the heat dissipation, characterized by the Nusselt number, has a different importance. For a Prandtl number Pr = 0.71, the (Gr) increases the heat exchange that is reflected by the increase of Nusselt number, and also participates to the formation of recirculation zones. The total Nusselt number Nu is increased when (Gr) is multiplied by 102. With regards to the distance (S) between the heat sources, the results show that Nu increases about 7% if the distance (S) doubles, and becomes approximately 17.8% when (S) quadruples. At the end, the heat transfer increases when increasing the distance (Le) of the upper exit length, especially on the second component. The total Nusselt number increases by 1.6% when (Le) increases by about 67%.

This study focused on numerical analysis of the parameters influencing the oil mist flow(MQL) outside a rotating tool, in non-contact configuration. This approach was a mandatorystep for the parameter optimizations before taking into account the material removing. Theoptimization of inner canalization geometries to a milling tool was performed to transferthe oil mist. The Reynolds Average Navier Stokes (RANS) and Lagrangian equations were usedto simulate the oil mist flow inside the canalizations by integrating the standardk-ε turbulence model with the STAR CCM+ commercial software. The dynamic numericalcalculation was used to optimize the inner canalizations of a milling tool. Because of theparticular external tool shape, the micro spray cooling is not guaranteed to reach thecutting edge. The external tool geometry, the inlet pressure, the shape and theorientation of the inner canalization geometries in the tool body and the rotation speedhave significant influence on the lubrication efficiency. The main goal of this study wasto improve this efficiency as function of these parameters. Thus, parameter sets givinggood lubrication were determinate for a type of tool.

We present a promising approach to reduce the difficulties associated with meshingcomplex curved domain boundaries for higher-order finite elements. In this work,higher-order XFEM analyses for strong discontinuity in the case of linear elasticityproblems are presented. Curved implicit boundaries are approximated inside an unstructuredcoarse mesh by using parametric information extracted from the parametric representation(the most common in Computer Aided Design CAD). This approximation provides local gradedsub-mesh (GSM) inside boundary elements (i.e. an element split by the curved boundary)which will be used for integration purpose. Sample geometries and numerical experimentsillustrate the accuracy and robustness of the proposed approach.

The Bayesian approach is a stochastic method, allowing to establish trend studies on thebehavior of materials between two periods or after a break in the life of these materials.It naturally integrates the inclusion of the information partially uncertain to support inmodeling problem. The method is therefore particularly suitable for the analysis of thereliability tests, especially for equipment and organs whose different tests are costly.Bayesian techniques are used to reduce the size of estimation tests, improving theevaluation of the parameters of product reliability by the integration of the past (dataavailable on the product concerned) and process, the case “zero” failure observed,difficult to treat with conventional statistical approach. This study will concern thereduction in the number of tests on electronic or mechanical components installed in amechanical lift knowing their a priori behavior in order to determine their a posterioribehavior.

The present research study includes thermal energy performance analysis of a flat platesolar collector, in order to cover a sensitivity analysis about effective variablescontributed to performance increasing approach. To obtain that, energy and momentumgoverning equations on a flat plate thermal collector were developed to achieve air outputtemperature and velocity profiles both in model and experiment. The model theory isvalidated with experiments by a set of flat plate thermal collectors, those located in(35◦44′35′′ N, 50◦57′25′′ E) coordinates and then were applied to carry outexperimental activities. Quantitative results depicted that the mean difference betweenpredicted and measured output air temperature in natural and forced convection scenarii is1.47 ◦C (3.5%) and0.9 ◦C (1.5%),respectively; however earlier research works and studies mentioned in literature, includeerror percentages in the range of 4–10%. Another quantification about, the average errorpercentages of estimated amounts of output air velocity profile values in natural andforced convection scenarii is 9% and 4%, respectively. This issue realizes the developedmodel in forced convection scenario more accurate than natural convection scenario.