Rheological simulation model

In principle there are two possibilities to get the informations over the material parameters. First we have a theoretic model modified from the model over high filled polymere melts. This model allows to meassure and evaluate the rheological parameters. On the other hand we have a rheological computer model called ESM (extruder simulation model), developed by the author, which brings us in the position to simulate the material parameters. 

A number of publications have appeared in the literature describing simulation models for pol3rmer flooding (1-8). The transport properties of the polymer, the interaction with the rock matrix, possible chemical reactions and the non-Newtonian rheological behaviour of polymeric liquids combine to make polymer flow through porous media very complex The main features which should be included in a polymer simulator for both field and laboratory use are as follows ... 

In the early days of rheological simulation, only the standard injection molding process of thermoplastics had been considered. Today, there are solutions for elastomers, thermosets, liquid silicone resin polymers, and also polymers for the reaction injection molding (RIM) process. Simulation programs have been developed for various materials as well as for various processing techniques on the shell model and are available in all these varieties. 

Leonov viscoelastic nematodynamics model was chosen for rheological simulation of TLCPs. The simulated viscosities have been compared with experimentally measured viscosity data, indicating a good fit in the shear rate range of 10-2000 s In the low shear rate region, the model did not predict negative normal stress difference for filled TLCPs. For unfilled TLCPs, good comparison has been observed between the simulated values of Ni and the experimental data. 

Performing numerical simulations of the extrusion process requires that the shear viscosity be available as a function of shear rate and temperature over the operating conditions of the process. Many models have been developed, and the best model for a particular application will depend on the rheological response of the resin and the operating conditions of the process. In other words, the model must provide an acceptable viscosity for the shear rates and temperatures of the process. The simple models presented here include the power law. Cross, and Carreau models. An excellent description of a broad range of models was presented previously by Tadmor and Gogos [4]. 

Wijmans, C.M., Dickinson, E. (1998). Simulation of interfacial shear and dilatational rheology of an adsorbed protein monolayer modeled as a network of spherical particles. Langmuir, 14, 7278-7286. 

Ayeni, K. Osisanya, S.O. Evaluation of Commonly Used Fluid Rheological Models Using Developed Drilling Hydraulic Simulator in Proc. 5th Canadian International Petroleum Conference, The Petroleum Society Calgary,... 

It is worth noting that one of the uses to which computers can be put is to derive continuum models for highly structured systems. Thus in the case of drilling muds, simulations on the scale of clay platelets can be used to provide rheological models for use in finite element models for flow mechanics, which are then used to derive Nusselt number estimates for uniaxial mean temperature predictions in oil wells. The range of length scales goes from 1 nm to 1000 m ... 

Structures 13C, 2H and 2H NMR spectroscopy (T2 relaxation times, signal intensity ratio versus generation) rheology studies electron microscopy computer-assisted molecular simulations, comparison to CPK models electrospray mass spectroscopy fluorescence probe analysis. 

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