In this study, the dynamic analysis of Pipeline Inspection Gauge (PIG) flow control innatural gas and liquid pipeline is considered. The basic equations are differential formsof the mass and linear momentum for compressible liquid and gas flows. The fluid flowequations and a linear momentum equation of the PIG are solved simultaneously using anappropriate numerical method. Solution of these nonlinear equations results in a set ofdiagrams for the variations of the fluid pressure, mass flow rate of the gas and the PIGvelocity through the pipeline. Comparing the results of mathematical model for the PIGwith the established experimental data in a segment of Ahwaz gas pipeline shows a goodagreement between the measurements and computations.

Safflower is an oil-seed crop with high quality oil that is used for producing healthyfoods and painting colors. This crop has valuable petals which have a lot of uses inmedicine, production of food colors and dyes for coloring fabrics, but such problem asdispersion of flowers, thorns of crops that hurt worker’s hands also lack of a suitableharvesting machine have enforced farmers to harvest petals by hand that is a hard work andnon-economic. In this study a prototype machine was designed and constructed. This machineincludes an engine, a radial fan with BI blades, a snout, a diffuser to separate petalsfrom airflow and a store; all parts are assembled on a trolley to move easily in farm.This machine picks safflower petals out and intakes through snout by the fan suctionpower. Petals go to diffuser where they are separated from airflow then fall to the store.Velocity of airflow in the snout was determined by a fan test duct in order to designdiffuser. At last three farms were harvested by this machine for economic analysis.Results show 657% increasing in amount of harvested petals by harvester machine incomparison with hand harvesting.

The market demand for machining and cutting of various plastics parts is in continuousincrease. The aim of this study is to extract prediction laws for surface roughness,cutting forces and temperatures evolution during the machining of two polyethylene pipesgrades (HDPE-100) and (HDPE-80). It was found that feed rate is the most prevailing factoron roughness criteria and that better surfaces are obtained during the machining of theharder HDPE-80 resin. Also, cutting speed improved surface quality for speeds up to 200m.min-1 but the rising interface temperature caused surface damage andmaterial rapid softening. Also, feed exponents, in mathematical models, were found to be 3to 4 times higher than those of cutting speed and depth of cut. An increase in the cuttingspeed led to a gradual reduction for the 3 cutting forces components (Fr,Fa and Fv) with a dominance of the tangential force(Fv). As expected, the value of the depth of cut had a large influenceon the temperature within the cutting zone. This temperature is slightly higher during themachining of HDPE-80 compared to that of HDPE-100 most probably because of hardnessdifferences. The analysis of variance (ANOVA) was performed to check the adequacy of themathematical models relating cutting parameters with roughness, cutting forces and globalcutting zone temperature.

This paper investigates the windage power losses generated by spur gears rotating in pureair by using a computational fluid dynamics (CFD) code. The three-dimensional simulationsare at first validated comparing CFD predictions with the power losses measured in similarconditions from other investigations. The volumetric flow rate which is expelled by theteeth is then analysed, and a correlation which is based on a classical approach used inturbomachinery is finally proposed which makes it possible to estimate windage losses forspur gears. It was observed that this latter approach seems satisfying since theformulation of the volumetric flow rate which is employed in the model is appropriate toeach gear.

This paper synthesizes a whole of work carried out on the spiral bevel gears fromquasi-static and dynamic models viewpoint. A sophisticated quasi-static model makes itpossible to calculate the tooth loads, the pressures, the instant mesh stiffness, and thedeflections on the flanks of spiral bevel gears. Based on these results, twothree-dimensional lumped parameter dynamic models are presented. The mechanical systemunder consideration comprises: a spiral bevel pinion and gear connected by a time-varyingnon-linear mesh stiffness function, and mounted on two shafts simulated by Timoshenko’sbeams supported by bearings. Two variants are considered which rely on different contactstiffness simulations: (a) using an averaged mesh stiffness function acting at thecentroid of the loaded areas on tooth flanks and (b) a more local approach based on adiscrete distribution of the local mesh stiffness, elements over the contact areas. Anumber of results are presented and commented which illustrate the interest of thesedynamic models.

Thermoplastic based composites containing different weight fractions of molybdenumdisulfide (MoS2) solid lubricant were developed by injection molding.Polymethyl methacrylate (PMMA) and polycarbonate (PC) were chosen for the thermoplasticmatrices. In order to characterize the interfacial adhesion between the matrices and thefiller, we observed the fracture morphologies of selected composites. Micrographs of thefractured surfaces showed removal of MoS2 particles by microcraking as well asthe presence of voids in the case of PMMA/MoS2 composites. These observationswere confirmed by complementary images obtained using the X-ray tomography. The additionof an appropriate coupling agent may improve the adhesion between the MoS2particles and the polymer matrix. Tribological behavior of the composites was alsoinvestigated using a ball-on-flat microtribometer with a high chromium steel ballantagonist. It was found that the addition of MoS2 particles didn’t improve thetribological performance of the composite in the case of PMMA matrix unlike the case of PCmatrix where the friction coefficient was considerably reduced.

Une double enceinte climatique conçue sur le principe de la méthode de la boîte chaudegardée a été mise au point afin d’étudier en laboratoire le comportement thermique ethygrique de différentes configurations de parois en bois. Le dispositif est dotéd’équipements de régulation lui permettant de reproduire des sollicitations climatiquesstationnaires ou dynamiques proches d’un climat réel et de suivre l’évolution des profilsde température et d’humidité dans les parois testées. Dans ce travail, le suivi ducomportement hygrothermique d’une paroi en ossature bois comportant des matériauxhygroscopiques et soumises à différentes conditions est rapporté. Les résultats ont montréque la capacité du dispositif à bien reproduire les conditions imposées a permis demesurer les propriétés importantes de parois en régime permanent (résistance thermique) ettransitoire (amortissement et déphasage thermique). Les essais réalisés ont également misen évidence le comportement hygroscopique des matériaux testés.

Une étude expérimentale du séchage convectif à haute température en vapeur d’eausurchauffée et du séchage à l’air d’une particule poreuse et sphérique du bois (hêtre) estprésentée. Un dispositif de macro-TG, dans lequel une particule est suspendue etcontinuellement pesée au cours du séchage, est utilisé. En prenant deux valeurs de lavitesse du fluide séchant (vapeur d’eau surchauffée ou air), nous avons mesuré la teneuren eau et la température du produit au cours des deux procédés de séchage. Aussi, on amontré que le bois séché en vapeur d’eau surchauffée est nettement de qualité supérieure àcelle obtenue à l’air. En effet, la particule du bois séchée en vapeur d’eau surchaufféegarde sa couleur naturelle alors que celle séchée à l’air noircit. Le procédé de séchageen vapeur d’eau surchauffée répond alors au mieux à l’exigence la plus demandée par lesindustriels qui est qualité du produit. Parmi les applications possibles de séchage de cesparticules est la fabrication du bois aggloméré.