New Approaches in Modeling Multiphase Flows and Dispersion in Turbulence, Fractal Methods and Synthetic Turbulence

The impact of Kinematic Simulations on quantum turbulence theory, by Demosthenes Kivotides.- 1 Introduction.- 2 Mathematical model;3 Results.- 4 Conclusion.- References.- Detached Eddy Simulation for turbulent flows in a pipe with a snowflake fractal orifice, by H. W. Zheng, F. C. G. A. Nicolleau and N. Qin.- 1 Introduction - motivation.- 2 Governing equations;3 Numerical discretization.- 4 Results.- 5 Conclusions.- References.- KS input spectrum, some fundamental works on the vibration spectrum of a self-similar linear chain, by T. M. Michelitsch, F. C. G. A. Nicolleau, A. F. Nowakowski and S. Derogar.- 1 Introduction;1.1 Input spectrum in the Kinematic simulation technique.- 1.2 Richardson’s locality-in-scale hypothesis.- 2 Experimental studies of fractal generated turbulence.- 3 Fundamental modelling;4 Spectral Graphs for self-similar linear chains.- 5 Construction of self-similar functions and linear operators.- 5.1 Construction of self-similar functions.- 5.2 A self-similar analogue to the Laplace operator.- 5.3 Continuum approximation - link to fractional integrals.- 6 The physical chain model.- 7 Conclusions.- References.- Can Kinematic Simulation predict Richardson’s regime? , by F. C. G. A. Nicolleau and A. Abou El-Azm Aly.- 1 Introduction.- 1.1 The two-particle dispersion problem.- 1.2 Observation of the Richardson law.- 2 Kinematic simulation.- 2.1 Kinematic simulation technique.- 2.2 Kinematic Simulation’s predictions of Richardson’s law.- 2.3 The KS method for isotropic turbulence.- 2.4 The Eulerian field time dependence.- 3 KS and Richardson Regime Validation.- 3.1 Particle pair diffusivity.- 3.2 Sensitivity to the energy spectrum power law.- 3.3 Effect of varying the unsteadiness parameter on the Validity of Richardson Regime.- 4 Conclusion.- References.- Incorporating linear dynamics and strong anisotropy in KS. Application to diffusion in rotating, stratified, MHD turbulence, and to aeroacoustics, by C. Cambon, F. S. Godeferd and B. Favier.- 1 KS for homogeneous isotropic turbulence. What remains to be done ?.- 1.1 Is the randomization process optimal?.- 1.2 Are the temporal random frequencies really random variables ?.- 2 Incorporating linear dynamics in KS. Application to rotatin and/or stratified flows.- 2.1 Analogy with the Rapid Distortion Theory.- 2.2 The role of inertial waves.- 2.3 Stable stratification with or without rotation.- 3 The linear dynamics of MHD turbulence.- 3.1 Basic equations.- coexistence of waves with anisotropic ohmic dissipation.- 3.2 Preliminary MHD results with and without rotation.- 4 Accounting for strong anisotropy.- 4.1 Anisotropy created by linear mechanisms from isotropic initial data.- 4.2 Anisotropic initialization, link to ’structures’.- 4.3 Some applications.- 5 Application to aeroacoustics in turbulence with and without rotation.- 5.1 Isotropic turbulence.- 5.2 Rotating turbulence.- 6 Conclusions and perspectives.- Appendices.- References.- Advances in Particle Representation Modeling of homogeneous turbulence. From the linear PRM version to the interacting viscoelastic IPRM , by S.C. Kassinos and E. Akylas.- 1 Introduction.- 2 The RDT formulation.- 3 The Structure Tensors.- 4 Particle Representation of the RDT of Homogeneous Turbulence.- 4.1 Particle Properties.- 4.2 Vector Identities of the Particle Properties.- 4.3 Evolution Equations of the Particle Properties.- 4.4 Representation of the One Point Statistics.- 5 The Interacting Particle Representation Model.- 5.1 Formulation of the IPRM.- 5.2 Evaluation of the IPRM.- 6 Summary and Conclusions.- References.- Oscillation-free Adaptive Simulation of Compressible Two-fluid Flows with Different Types of Equation of State, by H. W. Zheng, C. Shu, Y. T. Chew, and N. Qin.- 1 Introduction.- 2 Compressible Two-fluid Flows.- 2.1 Modelling with general form of equation of state.- 2.2 Oscillation-free analysis.- 3 Discretization on quadrilateral-cell based adaptive mesh.- 4 Results.- 4.1 Interface translation problem.- 4

This book contains a collection of the main contributions from the first five workshops held by Ercoftac Special Interest Group on Synthetic Turbulence Models (SIG42. It is intended as an illustration of the sig s activities and of the latest developments in the field.

This volume investigates the use of Kinematic Simulation (KS) and other synthetic turbulence models for the particular application to environmental flows.