Browsing by Author "ABDELMADJID CHEHHAT"

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    COMPUTATIONAL FLUID DYNAMICS OF THE TURBULENT AIR FLOW THROUGH A VANED DIFFUSER TURBOCHARGER
    (2014-10-10) ABDELMADJID CHEHHAT
    In this work a numerical study with moving reference frame (MRF) technique is made. Many research works both experimental and numerical on the impeller-diffuser interactive phenomenon have been undertaken so far. But it is found from the literature that the study on the impeller-diffuser-volute interaction as well on the performance of the turbocharger centrifugal compressor by varying the number of diffuser vanes has not been the focus of attention in these works. Hence a numerical analysis was accomplished in order to extensively explore impeller-diffuser fluid interaction in a real turbocharger used in military engines applications, when the number of diffuser vanes was changed at unaltered number of the impeller blades. It was concluded that the number of diffuser vanes gives a considerable effect on the pressure and temperature at the compressor outlet.
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    Free Convection in a Vertical Duct: Numerical Study
    (2011) ABDELMADJID CHEHHAT
    The subject of this paper is a direct numerical study of laminar and laminar-to-turbulent transient natural convection in a vertical duct, with a constant wall temperature, that exceeds the ambient fluid temperature. The governing equations are solved without modeling of the turbulence effect using a finite volume method. We presented the fields of velocity, temperature, and pressure as well as variation of the mean Nusselt number as a function of the Rayleigh number. The numerical simulation has been made for the Rayleigh number in the range from 1 to 105 for aspect ratios 3, 5, 8, and 12. The obtained results are compared with those given in the literature and a good agreement has been found.