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Item Open Access Dynamic properties of fluids from molecular simulations and entropy scaling(Stuttgart : Universität Stuttgart, Institut für Technische Thermodynamik und Thermische Verfahrenstechnik, 2022) Fischer, Matthias; Groß, Joachim (Prof. Dr.-Ing.)The design of most processes in chemical industry depends on reliable estimates of the transport properties of fluids. Various approaches exist for the prediction of these quantities, which can be used to compensate for insufficient experimental data. The present work deals with two of the approaches: Molecular simulations and entropy scaling. According to the latter approach, transport coefficients, such as shear viscosity, thermal conductivity or self diffusion coefficients, defined as dimensionless quantities using a suitable reference, are univariant functions of only the residual entropy of the fluid. The two methods, molecular simulations and entropy scaling are used jointly in order to achieve synergistic effects. A suitable mixture-model for entropy scaling models was investigated in molecular simulations as part of this work. Mixtures of simple model fluids, namely Lennard-Jones mixtures, are regarded and it is found that the principle of entropy scaling holds also for mixtures, to excellent approximation. Entropy scaling, in turn, is used to more efficiently design and evaluate molecular simulations. In this context, the TAMie force field developed in Stuttgart is assessed with respect to the accuracy of predicted transport coefficients. The TAMie model, like many other force fields developed for thermodynamic properties, uses rigid bond lengths between interaction sites within a molecule. In order to ensure a meaningful assessment of transport coefficients in Molecular Dynamic simulations, an analysis of bond-length models is conducted: what is the influence of the model for intramolecular atomic bonds on the predicted static and dynamic fluid properties? It is shown that it is possible to obtain the same results for transport coefficients with flexible atomic bonds, within statistical accuracy, as with the same force field but using a rigid description of the bonds. Within the context of the simulation studies carried out in this thesis, a workflow has been developed that enables efficient evaluation of simulations for determining transport properties. In combination with entropy scaling, this work presents a methodology that can be used to efficiently determine transport quantities from molecular simulations, thus enabling extensive simulation studies for either predicting fluid properties or to enable force field development where transport coefficients are considered in the objective function.