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search.filters.applied.f.access: openAccess × Author: John, Volker × Type: Text × Type: report × Subject: Population balance systems ×

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Now showing 1 - 3 of 3
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    A numerical method for the simulation of an aggregation-driven population balance system
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2011) Hackbusch, Wolfgang; John, Volker; Khachatryan, Aram; Suciu, Carina
    A population balance system which models the synthesis of urea is studied in this paper. The equations for the flow field, the mass and the energy balances are given in a three-dimensional domain and the equation for the particle size distribution (PSD) in a four-dimensional domain. This problem is convection-dominated and aggregation-driven. Both features require the application of appropriate numerical methods. This paper presents a numerical approach for simulating the population balance system which is based on finite element schemes, a finite difference method and a modern method to evaluate convolution integrals that appear in the aggregation term. Two experiments are considered and the numerical results are compared with experimental data. Unknown parameters in the aggregation kernel have to be calibrated. For appropriately chosen parameters, good agreements are achieved of the experimental data and the numerical results computed with the proposed method. A detailed study of the computational results reveals the influence of different parts of the aggregation kernel.
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    A comparative study of a direct discretization and an operator-splitting solver for population balance systems
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2014) Anker, Felix; Ganesan, Sashikumaar; John, Volker; Schmeyer, Ellen
    A direct discretization approach and an operator-splitting scheme are applied for the numerical simulation of a population balance system which models the synthesis of urea with a uni-variate population. The problem is formulated in axisymmetric form and the setup is chosen such that a steady state is reached. Both solvers are assessed with respect to the accuracy of the results, where experimental data are used for comparison, and the efficiency of the simulations. Depending on the goal of simulations, to track the evolution of the process accurately or to reach the steady state fast, recommendations for the choice of the solver are given.
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    Numerical methods for the simulation of an aggregation-driven droplet size distribution
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2012) Bordás, Robert; John, Volker; Schmeyer, Ellen; Thévenin, Dominique
    A droplet size distribution in a turbulent flow field is considered and modeled by means of a population balance system. This paper studies different numerical methods for the 4D population balance equation and their impact on an output of interest, the time-space-averaged droplet size distribution at the outlet which is known from experiments. These methods include different interpolations of the experimental data at the inlet, various discretizations in time and space, and different schemes for computing the aggregation integrals. It will be shown that notable changes in the output of interest might occur. In addition, the efficiency of the studied methods is discussed.