Due to their stability under high mechanical and thermal loads nickel-based alloys generate high cutting forces and temperatures during machining which adversely affect tool life. Especially in broaching with form shaped tools, deviations from the original tool geometry cause an inacceptable product quality. In aero engine industry, where quality standards for machining of safety critical parts are very high, this cannot be tolerated. Because of its tool geometry broaching is different from other machining processes: due to the high ratio between cutting edge radius and chipping thickness, the influence of the tool wear at the cutting edge is strong, especially for the finishing section. In order to guarantee stable machining processes in production, monitoring methods are desired that are capable to recognize changes in cutting conditions. The EU funded ACCENT project focuses on this challenge: the goal is to use process monitoring to make conclusions about the product quality during machining and, if necessary make adjustments to process input parameters to keep the quality measures in a defined window.

In industrial area, drilling is one of the most commonly used machining operations. Today, conventional drilling methods have found their limits in deep hole drilling. To be able to push these limits, we have developed a new technology: vibratory drilling. The aim of this study is to determine the influence of the twist drill geometry on performance of the self vibratory drilling head. For that reason, it is necessary to identify the geometrical properties which have the strongest influence on axial vibrations of twist drill and on chip fragmentation. Moreover, we have also validated the experimental results by a simulator which can predict the behaviour of the self vibratory drilling head by taking into account geometrical defects of the tool.

Tilting-Pad Journal Bearings (TPJB) are commonly used on high-performance turbomachinerydue to their excellent stability properties at high speed when compared to other designsfor oil film bearings. Hence, efforts have been made to improve the accuracy for theavailable models for these mechanical devices, achieving nowadays anelasto-thermo-hydrodynamic formulation. On the other hand, the basic design of theTilting-Pad Journal Bearing has been modified in order to transform it into a smartmachine element. One approach to do so is to inject pressurized oil directly into thebearing clearance through holes drilled across the bearing pads. By adjusting theinjection pressure, it is possible to modify the dynamic characteristics of the bearing. Acontrollable lubrication regime is obtained, allowing to expand the operational boundariesof the original design. This work focuses on presenting an elasto-thermo-hydrodynamicmodel (ETHD) for the Tilting-Pad Journal Bearing, including the effect ofthe controllable lubrication system. The basic model is validated by comparing its resultsagainst theoretical and experimental results available in the literature. Then, thevalidated code is used to show the benefits of applying a controllable lubrication regime,by means of the modification of the thermal and dynamic behaviour of the bearing.

This paper presents the application of new time frequency method, ensemble empirical modedecomposition (EEMD), in purpose to detect localized faults of damage at an early stage.EEMD is a self adaptive analysis method for non-linear and non-stationary signals and itwas recently proposed by Huang and Wu to overcome the drawbacks of the traditionalempirical mode decomposition (EMD). The vibration signal is usually noisy. To detect thefault at an early stage of its development, generally the residual signal is used. Thereexist different methods in literature to calculate the residual signal, in this paper wemention some of them and we propose a new method which is based on EEMD. The results givenby the different methods are compared by using simulated and experimental signals.

Braking operation is a process which converts the kinetic energy and the potential energyof the vehicle into other energies. The major part of the mechanical energy is transformedinto heat. During the braking phase, the frictional heat generated at the interfacedisc–pads can lead to high temperatures. This phenomenon is even more important that thetangential stress as well as the relative sliding speeds in contact are important. Theobjective of this study is to analyse the thermal behavior of the full and ventilatedbrake discs of the vehicles using computing code ANSYS. The modeling of the temperaturedistribution in the disc brake is used to identify all the factors and the enteringparameters concerned at the time of the braking operation such as the type of braking, thegeometric design of the disc and the used material. The results obtained by the numericalsimulation are satisfactory compared with those of the specialized literature.

Numerical simulations of the isothermal turbulent jets mixing flows exhausted from twodifferent circular lobed nozzles are presented in the present paper. The numerical studieshave been conducted using a Favre-Reynolds Averaged Navier-Stokes approach, using thesecond-order Reynolds Stress Model (RSM) and structured mesh. Thevalidation of the numerical results with experimental data has been carried out only withone nozzle for the same configuration. This comparison shows reasonable agreement,principally, in terms of centreline longitudinal velocity, longitudinal fluctuatingvelocity and streamwise vorticity. In the second part, the effects of the inlet isothermallobed jet on the mixing process with variable density have been studied numerically. Forthe same area exit geometries (axisymmetric and asymmetric), a qualitative comparison ofthe numerical results with experimental data have been presented. All these indicated thebetter mixing enhancement performance of a lobed nozzle over asymmetric and axisymmetricnozzles respectively.

Le séchage cinétique des particules en bois dans un lit de sable fluidisé est étudié. Leréacteur est constitué d’une colonne de verre cylindrique où la fluidisation desparticules de sable est obtenue grâce à un débit d’air sec, filtré, dont la pression estajustée par un détendeur et dont le débit est mesuré. Le sable a un diamètre moyen de0,155 mm et une masse volumique de 2650 kg.m-3. La température et l’humiditérelative de l’air sont respectivement mesurées par des thermocouples et par un hygromètrecapacitif à film mince mesurant l’humidité absolue de l’air à l’admission et à la sortiedu lit fluidisé. L’installation expérimentale est conçue pour évaluer la valeurinstantanée de l’humidité du bois. Le taux de séchage augmente avec la température et lamasse des particules de bois. Ces comportements sont examinés en tenant compte desdifférents paramètres (température, vitesse de l’air, humidité initiale du bois).

Aujourd’hui, différents types de systèmes de Chauffage, de Ventilation et deConditionnement de l’air (CVC) sont utilisés. À un niveau équivalent de confort thermique,la consommation énergétique diffère de l’un à l’autre. De ce fait, il est plus raisonnablede choisir le système garantissant un meilleur rapport confort thermique/consommationénergétique. Dans cette étude, un système combiné plancher chauffant–plafondrafraîchissant a été considéré. Afin d’estimer la fiabilité de ce type de systèmes CVC, lecomportement thermique d’un bâtiment simple intégrant cette technique de chauffage et derafraîchissement a été modélisé. Le modèle développé, utilisant l’approche Bond Graph(BG), a servi d’outil de simulation afin d’évaluer les performances énergétiques dusystème combiné. Il s’est avéré que cette technique répond aux besoins en chaud et enfroid tout en maintenant un meilleur confort thermique. Cependant, elle est bien adaptéedans les climats relativement secs et froids.