Towards multi-scale modelling of complex liquids using hybrid particle—continuum schemes

Owing to the interplay between molecular and mesoscopic processes, the modelling and simulation of complex liquids at nano- and micron-scales require a multi-scale approach. A hybrid technique is proposed to handle multi-scale phenomena, which retains the full molecular nature of the system where it is of interest while coarse-graining it elsewhere. The method couples molecular dynamics (MD) and fluctuating hydrodynamics (FH) based on the Landau theory. Mean flows involving transport of transversal (shear) and longitudinal momentum (sound) are coupled across the interface of both MD and FH domains. Hydrodynamic fluctuations of mass and momentum are transferred, preserving consistency with hydrodynamics and thermodynamics. Here the hybrid method is illustrated by studying the reflection of water sound waves against a lipid (dimyristoylphosphatidylcholine) monolayer.

Stress State of Shells With Residual Strains: Refined Model and Matrizant Method

An axisymmetric problem on determination of the stress state for limited cylindrical shells caused by residual strains is considered. Using of suggested matrizant numerical-analytical method the solution of this problem in refined statement is given. The theoretical model allows taking into account of the effect of transversal shear deformation and the compression of normal. Numerical analysis of the stress state is presented.

Dynamic Instability Analysis of Internally Damped Rotors

This paper deals with the study of dynamic instabilities within rotating assemblies due to internal damping effects. In order to consider realistic mechanical properties, in terms of internal damping, a rheological model is associated to a general finite element beam approach, including transversal shear. After a description of the theoretical background (choice of internal damping model and equation of motion), an application illustrates the ability of the proposed model. The influence of damping on frequencies and on instability thresholds is investigated using a parametric study. Results are compared to those obtained from an analytical approach as well as from experiments.