Process Modelling

Industrial processes are commonly described with block-models of components exchanging mass and energy. The entities of the block models are units of process components with often complex transfer functions derived from first principle balance equations or empirical process knowledge. In many cases the underlying physics is so complex, that models contain a larger number of empirical parameters and correlations. A decisive gap here is that such lumped parameter codes lose prediction capability for 3D and transient process conditions. Also their accuracy diminishes for multiphase flow structures in process spaces, due to their inherent physical complexity. Advanced computational physics simulations are innovation drivers here.

TOMOCON objectives

TOMOCON shall employ and further develop a set of computational physics methods in design, test and validation of model-based control strategies and design of sensor-actuator systems. Employed methods are computational fluid dynamics simulations (CFD) (flow pattern prediction in metal casting moulds, batch reactors and separators and FEM-based field simulations for microwave heating and tomography, ultrasound wave propagation in crystallization and design of electrical and magnetic tomography sensors. Process models for the four demonstration cases shall be developed by partners with key expertise in this field. CFD simulations for inline separators will be made capable of simulating flow regime changes and dispersion states of phases. This is in line with recent developments at INP Toulouse [1] coupling Euler/Euler two-fluid simulation with VOF methods. CFD simulations of liquid metal two-phase flow have to cope with grossly varying liquid viscosities and local phase change [2]. Microwave drying simulations require multi-physics coupling of electrical field, heat transport in solid body and porous body convection [3], [4]. Furthermore we use CFD for prediction of large scale mixing and its coupling to local supersaturation and large viscosity changes in batch reactors [5]. The work starts with simple box-chart models of each process, developed in state-of-the-art process modelling tools, like ACM. In a second stage a more sophisticated modelling using advanced simulation tools (FEM, CFD) shall be implemented and tested. On this basis virtual process models are developed and coupled sensors and controllers. While each partner in TOMOCON uses its own simulation code, full description of new algorithms in publications, publicly accessible data repositories and open source software distribution secures a broad dissemination of TOMOCON results.

[1] D. Legendre et al. (2015): Comparison between numerical models for the simulation of moving contact lines, Comp. Fluids 113, 2-13.

[2] S. Kenjeres (2012): Recent achievements and challenges in modelling and simulation of complex multi-scale MHD phenomena, ASME 2012 Fluids Engineering Division Summer Meeting, FEDSM 2012, Rio Grande; Puerto Rico.

[3] B. Lepers, G. Link, et al. (2014): A drying and thermoelastic model for fast microwave heating of concrete. Frontiers in Heat and Mass Transfer (FHMT), doi:10.5098/hmt.5.13.

[4] S. Soldatov, G. Link, et al. (2016): Dielectric characterization of concrete at high temperatures. 2016. Cement and concrete composites, 73, 54–61.

[5] M. Liiri, T. Koiranen, et al. (2002): Secondary nucleation due to crystal-impeller and crystal-vessel collisions by population balances in CFD-modelling, J. Cryst. Growth 237-239, 2188-2193.