Browsing by Author "Mansouri, K."

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    Analysis of the effects of inlet temperature frequency in fully developed laminar duct flows
    (Springer, 2010) Hadiouche, A.; Mansouri, K.
    Unsteady heat transfer for a fully developed laminar flow inside a parallel-plate channel and circular duct that are subjected to a periodically varying inlet temperature is studied. The thermal capacitance of the duct wall and the boundary condition that accounts for external convection are considered. An exact solution is presented for this extended Graetz problem as the result of using a new methodology based on a variational method. The quasi-steady approach that employs a heat transfer coefficient at the liquid–solid interface is also investigated, and the results are compared with the variational solution. The damping and phase lag coefficients as functions of the inlet temperature frequency are presented in graphical form
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    An analytical study of the periodic laminar forced convection of non-Newtonian nanofluid flow inside an elliptical duct
    (Elsevier Ltd, 2018) Ragueb, H.; Mansouri, K.
    In this study, an analytical solution was obtained for a laminar forced convection of non-Newtonian nanofluid flowing inside an elliptical duct, with inlet temperature varying periodically with the time. The solution was obtained using the Generalized Integral Transform Technique (GITT). The thermal behavior of Cu-water non-Newtonian nanofluid, described by the power-law model was investigated. Also, an accurate correlation was established to estimate the thermal length required to achieve 99% of the amplitude attenuation. The results show a significant effect of aspect ratio β/α and fluid behavior index on the temperature amplitude reduction. For instance, an elliptical duct with β/α = 0.25 reduces the thermal length Lth more than 50% compared with circular duct. Adding nanoparticles until 5% increases the heat transfer coefficient up to 27% for the cylindrical tube. Besides, the heat transfer coefficient is improved over 42% relatively to the cylindrical configuration by reducing the aspect ratio to 0.25. Therefore, adding 5% of nanoparticles both using an elliptical duct with β/α = 0.25, improves the mean heat transfer coefficient around 83% compared to the flow of water base fluid inside a cylindrical duct
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    Application of integral transform technique to the transient laminar flow heat transfer in the ducts
    (Elsevier, 2010) Hadiouche, A.; Mansouri, K.
    In this paper, a theoretical study of laminar forced convection inside ducts, subjected to periodically varying inlet temperature is presented. A thermal diffusion in the duct walls and a boundary condition which accounts for external convection are considered. In the first part, this problem is solved by applying a Generalized Integral Transform Technique (GITT). The complex eigenvalues and coefficients results are listed and compared with the literature. In the second part, the Quasi-steady Approach (QSA) which employs a constant heat transfer coefficient at liquid–solid interface is also investigated and compared with the GITT solution. The bulk temperature, Nusselt number, the damping and phase lag coefficients as function of the inlet temperature frequency are plotted
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    Optimisation multi-objectif des parametres de conception d’un robot delta dedie a l’usinage a grande vitesse
    (2011) Belaidi, Idir; Mansouri, K.; Maiza, B.; Mohammedi, K.; Bouziane, A.
    Cet article présente un modèle pour l’optimisation multi-objectif des paramètres de conception d’un robot DELTA dédié à l’usinage à grande vitesse, basée sur la mise en oeuvre de l’algorithme génétique NSGAII sous Matlab™. Le conditionnement de la matrice jacobienne et la capacité d’accélération de la nacelle sont les fonctions ‘objectif’ du modèle d’optimisation, tandis que les forces extérieures de coupe agissant sur la nacelle, les limites cinématiques articulaires, la déformation des barres, les configurations singulières, ainsi que les forces des moteurs, qui doivent être compatibles avec les limites de performances attendues, représentent les contraintes à respecter