New analytical solution for solving steady-state heat conduction problems with singularities

A problem of steady-state heat conduction which presents singularities is solved in this paper by using the conformal mapping method. The principle of this method is based on the Schwarz-Christoffel transformation. The considered problem is a semi-infinite medium with two different isothermal surfaces separated by an adiabatic annular disc. We show that the thermal resistance can be determined without solving the governing equations. We determine a simple and exact expression that provides the thermal resistance as a function of the ratio of annular disc radii

Phénomènes de constriction thermique durant le procédé de dépôt par projection plasma

Les densités de flux mises en jeu lors de la réalisation de dépôts par projection thermique culminent à quelques centaines de W/mm2. La durée de l'étalement des gouttes est extrêmement faible, de l'ordre de la s. Les phénomènes interfaciaux de constriction thermique dépôt/substrat jouent un rôle extrêmement important puisqu'ils contrôlent le refroidissement du dépôt par le substrat et conditionnent de ce fait le comportement thermomécanique du dépôt. Nous présentons dans ce travail une approche analytique destinée au calcul de la résistance thermique de constriction durant l'étalement d'une goutte projetée sur un substrat et étudions l'effet de la vitesse sur ce phénomèn

A semi-analytical solution of micro polar flow in a porous channel with mass injection by using differential transform method

In this letter, the differential transform method (DTM) was applied to the micro-polar flow in a porous channel with mass injection. Approximate solutions of the governing system of nonlinear ordinary differential equations were calculated in the form of DTM series with easily computable terms. The validity of the series solutions were verified by comparison with numerical results obtained using a fourth order Runge–Kutta method. The computed DTM velocity profiles are shown and the influence of Reynolds number on the velocity component in x-direction is discussed

Le rôle du management de la diversité culturelle dans la résilience organisationnelle : Revue théorique

Today's businesses operate in an increasingly complex and dynamic world where unexpected events are everywhere. As such, they must develop the resilience to handle unexpected disruptions, maintain high performance, and even thrive. There is preliminary evidence in research that cultural diversity plays an important role in building organizational resilience. Despite numerous studies on resilience and diversity, the connection between these two concepts has remained largely unexplored in the literature. The purpose of this paper is to examine the impact of cultural diversity management on organizational resilience by answering the following questions: What is the role of cultural diversity in the development of organizational resilience? To answer this question, we relate existing research on elements of organizational resilience to results on cultural diversity in organizations. This article affirms the need to reflect on the importance of cultural diversity for organizations working to actively build organizational resilience. Indeed, cultural influence plays an important role in employee training, location selection, leadership style, and management of external stakeholders and alliances to increase organizational resilience.   Keywords : Management, cultural diversity, organizational resilience, human resources JEL Classification : M14 Paper type : Theoretical ResearchLes organisations évoluent aujourd'hui dans un monde de plus en plus complexe et fluctuant, où les événements inattendus sont omniprésents. Elles doivent donc développer des capacités de résilience pour gérer les perturbations inattendues, maintenir des performances élevées, voire prospérer et se développer. Dans la recherche, il y a des indications préliminaires que la diversité culturelle joue un rôle important non négligeable dans le développement de la résilience des organisations. Cependant, bien qu'il existe de nombreuses études sur la résilience et la diversité, le lien entre ces deux concepts reste inexploré dans la littérature. L'objectif de cet article est d'étudier l'influence du management de la diversité culturelle sur la résilience organisationnelle en répondant à la question suivante : Quel rôle joue la diversité culturelle dans le développement de la résilience organisationnelle ? Pour répondre à cette question, nous établissons un lien entre les recherches existantes sur les éléments de résilience organisationnelle et les résultats de la diversité culturelle au sein des entreprises. Cet article confirme la nécessité de réfléchir à l'importance de la diversité culturelle pour les organisations qui se consacrent au développement proactif de leur résilience organisationnelle. En effet, les influences culturelles jouent un rôle important dans la formation des ressources humaines, le choix du lieu d'implantation, les styles de leadership et la gestion des parties prenantes et des alliances externes pour améliorer la résilience organisationnelle.   Mots clés : Management, diversité culturelle, résilience organisationnelle, ressources humaines JEL Classification : M14 Type du papier : Recherche théoriqu

Thermal behavior of an active electronic dome contained in a tilted hemispherical enclosure and subjected to nanofluidic Cu-water free convection

This study examines the thermal behavior of a hemispherical electronic component subjected to a natural nanofluidic convective flow. During its operation, this active dome generates a high power, leading to Rayleigh number values reaching 4.56×109. It is contained in a hemispherical enclosure and the space between the dome and the cupola is filled with a monophasic water-based copper nanofluid whose volume fraction varies between 0 (pure water) and 10%. According to the intended application, the disc of the enclosure may be tilted at an angle ranging from 0° to 180° (horizontal disc with dome facing upwards and downwards, respectively). The numerical solution has been obtained by means of the volume control method. The surface average temperature of the dome has been determined for many configurations obtained by combining the Rayleigh number, the cavity’s tilt angle and the nanofluid volume fraction which vary in wide ranges. The temperature fields presented for several configurations confirm the effects of natural convection. The results clearly highlight the effects of these influence parameters on the thermal state of the assembly. The study shows that some combinations of the Rayleigh-tilt angle-volume fraction are incompatible with a normal operating system at steady state and that a thermoregulation is required. The correlation of the temperature-Rayleigh-Prandtl-angle type proposed in this work allows to easily carry out the thermal dimensioning of the considered electronic assembly.</p

Natural convection within water-zno nanofluid-filled hemispherical enclosure with a cubic electronic device

This work qualifies and quantifies the nanofluidic natural convective phenomena occurring in a hemispherical enclosure used for electronics applications. This cavity consists of a disk thermally insulated on its rear face, an active cube centered on the disk which generates a constant heat flux and an isothermal dome. The disc of the cavity remains horizontal while its dome is oriented either upwards or downwards. The considered nanofluid is a mixture of water with metallic ZnO nanoparticles. In order to examine the influence of these nanoparticles on the natural convective heat transfer, three values of the volume fraction considered: 0% (pure water), 1% and 5%. The dimensionless governing system of the problem under consideration is solved by means of the control volume method in combination with the SIMPLE algorithm. The structured mesh is composed of triangular surfacic elements and tetrahedral in the volumic domain. Temperature and velocity distributions are presented for some configurations and convective heat transfer is examined for all processed ones. The natural convective heat transfer is quantified by means of Nusselt-Rayleigh-Prandtl correlations.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers

Influence of Gemetrical and Thermal Parameters on the Thermal Comportment of a Pin-on-Disk System

Strong temperature gradients are often the cause of malfunctions taking place in mechanical systems which associate two rubbing solids. This work presents the thermal behaviour of a system consisting on a rotating disk in rubbing contact with a pin. Immersed in an environment characterized by a surface conductance h and a temperature Tf , the disk is subjected to localised heat flux generated by the friction with the pin, eccentric with respect to the rotating axis of the disk. Several parameters intervene decisively on the local heat transfer and therefore on the temperature of the contact surface between the two solids in friction. In addition to the conductance, other parameters as the angular velocity of the disk, the frictional heat flux or the pin diameter and its off center with respect to the disk rotation axis, play a major role in the thermal exchange. The present work examines the influence of such parameters on the thermal solution. An analytical expression is proposed for the calculation of the 3D disk´s temperature. The presented thermal cartographies make possible to locate the zones of the system undergoing the greatest temperature gradients and thus the associated spots of mechanical rupture. Results are compared with other analytical solutions found in the specialized literatu