Publications Search Results

Now showing 1 - 6 of 6
  • Publication
    Tropfenschwarmanalytik mittels Bildverarbeitung zur Simulation von Extraktionskolonnen mit Populationsbilanzen
    ( 2011)
    Mickler, M.
    ;
    Didas, S.
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    Jaradat, M.
    ;
    Attarakih, M.
    ;
    Bart, H.-J.
    Modern methods based on population balance methods permit a fast and accurate calculation of important quantities within extraction processes. The approaches show a good correlation between experiments and simulations with a deviation of the Sauter diameter d32 smaller as 5 % (stirred vessel 450 mm) and 7 - 12 % (column 450 mm). With the help of an optical measuring technique droplet swarms are examined transiently. The current limit of the transmitted light technique is at 16 - 20 vol.-% without further optimization. The limit of incident light technique is above 30 vol.-%. Distance transformation and watershed segmentation algorithms enable the analysis of the droplet images.
  • Publication
    A CFD-population balance model for the simulation of Kuhni extraction column
    ( 2011)
    Hlawitschka, M.W.
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    Jaradat, M.
    ;
    Chen, F.
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    Attarakih, M.
    ;
    Kuhnert, J.
    ;
    Bart, H,-J.
  • Publication
    The normalized quadrature method of moments coupled with finite pointset method
    ( 2011)
    Wächtler, T.F.
    ;
    Kuhnert, J.
    ;
    Attarakih, M.
    ;
    Tiwari, S.
    ;
    Klar, A.
    ;
    Bart, H.-J.
    This work reports the numerical performance of the Normalized Quadrature Method of Moments (NQMOM) involving more than one quadrature node (secondary particle) for dispersed phase flows coupled with the Finite Pointset Method (FPM). At first, the model used for the dispersed phase acting in a continuous environment is discussed briefly, followed by a theoretical discussion of NQMOM and FPM. Further sections report the numerical performance for test problems with increasing difficulty.
  • Publication
    Integral formulation of the population balance equation using the cumulative QMOM
    ( 2011)
    Attarakih, M.
    ;
    Jaradat, M.
    ;
    Hlawitschka, M.
    ;
    Bart, H.-J.
    ;
    Kuhnert, J.
    The integral formulation of the population balance equation using the CQMOM presents a novel and hierarchical method to couple the QMOM and the physically evolving particle size distribution. Here, not only is the cumulative number density function reconstructed, but also its low-order moments. The numerical analysis of the method shows two desirable properties: First, it can be considered as a free-mesh method, since the solution of each integral equation at the current grid point does not depend on the other ones. Second, the accuracy of the targeted low-order cumulative moments depend only on the nodes and weights of the cumulative Gauss-Christoffel quadrature, but not on sampling the continuous low-order cumulative moments. So, the CQMOM is a general integral formulation of the population balance equation and is an effective numerical scheme in which the QMOM is imbedded as a limiting case.
  • Publication
    On a high resolution Godunov method for a CFD-PBM coupled model of two-phase flow in liquid-liquid extraction columns
    ( 2010)
    Zeidan, D.
    ;
    Attarakih, M.
    ;
    Kuhnert, J.
    ;
    Tiwari, S.
    ;
    Sharma, V.
    ;
    Drumm, C.
    ;
    Bart, H.-J.
    This paper is about the numerical solutions for a computational fluid dynamics-population balance model (CFD-PBM) coupled model of two-phase flow in a liquid-liquid extraction column. The model accounts for a complete description between both the dispersed and continuous phases, and constitutes a hyperbolic system of equations having a linearly degenerate nature. A numerical algorithm based on operator splitting approach for the numerical solution of the model is used. The homogeneous part is solved using the TVD MUSCL-Hancock scheme. Numerical results are presented, demonstrating the accuracy of the proposed methods and in particular, the accurate numerical description of the flow in the vicinity of the contact discontinuities.
  • Publication
    Coupling of the CFD and the droplet population balance equation with the finite pointset method
    ( 2008)
    Tiwari, S.
    ;
    Drumm, C.
    ;
    Attarakih, M.
    ;
    Kuhnert, J.
    ;
    Bart, H.-J.
    In this paper we present the liquid-liquid two-phase flow simulations of a stirred extraction column with the help of our own developed meshfree method called the Finite Pointset Method (FPM). The primary (continuous) phase is modeled by the incompressible Navier-Stokes equations. The motion of the secondary (dispersed) phase is simulated by solving the equation of motion in which inertia, drag and buoyancy forces are taken into account. The size of the droplets is obtained by solving the droplet population balance equation (DPBE). The DPBE is solved by the Sectional Quadrature Method of Moments (SQMOM). The coupling between both phases is performed by considering the momentum transfer from each phase. In this work, some simulations in two and three dimensional cases with constant breakage and aggregation kernels are presented.