also on experimental efforts related to scaled problems see more in

NATO Advanced Study Institute PST.ASI.980064

"Flow and Transport Processes in Complex Obstructed Geometries: from Cities and Vegetative Canopies to Industrial Problems"

http://www.hydromech.kiev.ua/eng/news.htm

2012 - well, sorry for them, they can not keep their own website and data in it. Their contemporary institute website is the pitiful sight.

Back to 2004 reviews:

This is probably the first so specific high level meeting on the topic of how to deal with and construct the responding models and procure experiments for this task. It's not to say that this is the new theme, not at all. The two-phase symposia are known to penetrate the large conferences and congresses in many technical disciplines for decades. Still, with insufficient, as for the industry and crucial technologies, results of "heuristic," "empirical and semiempirical" methods and approaches, see analysis in our -

It's worth to note also, that there is the large scale project combining the industry's (large corporations) and government's (USA) effort run by NSF for the same reason, well not exactly for the environmental look-up, but primarily for benefits of industrial technologies.

My talk had the content of general basics and of the many specifics dealing with and solving the collective, scaled physics problems, among those starting with the problems in Fluid Mechanics as one of the most valuable sources of such problems.

Two Scale Non-Linear and Turbulent Transport in Highly Porous and Rough Domains. Applications in Urban Pollution Modeling, Chemical Technology, Thermal Physics and Fluid Mechanics, Groundwater Modeling, and Technologies.

V.S. TRAVKIN

HSPT, Chatsworth, California, USA

NATO ADVANCED STUDY INSTITUTE
NATO ASI. 980064

Kiev, Ukraine, May 4 - 15, 2004

At first we would like to explain how the lower scale transport models for forced, single phase fluid nonlinear and turbulent convection were extended for non-uniformly and randomly structured highly porous media as the two scale mathematical models. The random characteristics of the porous medium were simulated by the use of regular and specified statistical, pre-assigned solid phase morphologies. Throughout the course of theory and models development and evaluation, numerous issues consistently reappeared.These issues were the impact of medium morphology upon transport process characteristics, methods for the closure of the mathematical equations, the incorporation of specifics of turbulent mass, momentum and heat transfer process descriptions into the models, the expression of physically accurate boundary conditions, and coupled transport modes in highly porous media.

Basic governing equations for nonlinear and turbulent transport in porous media were first developed in 80-th. Developed - turbulent fluctuations simulation equations averaging; the multiscale hierarchical description of transport equations with nonlinear and turbulent regimes between two conjugate porous media. Were developed closures of HSP-VAT two scale problems via the direct micro-modeling in the lower scale environment. First developed - methods of closure in globular morphology problems and developed method of verification of the averaging theorems using the direct micro-scale modeling.

New type of 1D momentum transport law in the porous medium resembling the Poiseuille's law was formulated. Non-Newtonian fluid flow in micropores and governing equations for these non-linear problems, like averaging, fine scale phenomena and pore roughness influence. Among many possible models for turbulent momentum in porous media, the so-called k-epsilon turbulence models were considered to be appropriate for the lowest level of hierarchical modeling. The averaging of these equations is based on strict principles developed for application of Hierarchical Scaled Physics-Volume Averaging Theory (HSP-VAT).

We have solved exactly using the HSP-VAT the few two-scale problems in various physics disciplines, among them the problems for the stochastic distribution straight pore porous medium laminar and turbulent flow and heat transfer on the two (2) scales. Some of these problems are given in each textbook on porous medium transport, but never were solved correctly even for laminar flow -

Another very much known and taught problem is the diffusivity problem in cross the superlattice or multilayer. Until recently, this problem was solved incorrectly for only the one scale involved mathematical models and their solutions. These are obviously insufficient solutions (with different BC), as we have shown in our two-scale solution -

An understanding of the ways how the two- and three phase Urban Rough Layer (URL) phenomena of transport have to be modeled with the HSP-VAT scaled approach, which originally was developed for vastly different scale and physical phenomena, was the opening point in development of turbulent transport scaled modeling in porous media and for the URL. The development and application of heterogeneous nonlinear and turbulent phenomena scaled description using the HSP-VAT began in air pollution modeling in 1982-86. Problems ranging from experimental morphometrical data in one of built-up area in the city of Kiev were analyzed with the aid of a specialized set of programs for morphometric processing and simulation of experimental data of the URL in 1983-84. The urban roughness layer turbulent transport HSP-VAT models offered not general, but strictly experimental allowance for the morphological characteristics of the randomly nonhomogeneous roughness layer of specific urban housing systems and phytocenosis and made it possible to assess their effect on the characteristics of the turbulent boundary layer and diffusion of harmful impurities in the urban roughness layer.

Over previous decades, numerous methods have been developed to predict transport and fate of contaminants in soil. However, these methods are mostly limited to homogenized one-, two- or, rarely, three-dimensional models. A hierarchical HSP-VAT modeling approach to the solution of soil and groundwater contamination transport alleviates the added degrees of uncertainty by including, instead of marginalizing, the physics of the transport processes. It is clear that the coefficient of permeability, K in Darcy law notation can not be used by itself as the influence of many physical mechanisms occurring in porous media fluid flow, even for one-structured morphology, is not contained in its variant models. Homogeneous equations for heat and mass transport in use at this time are only appropriate for small scale laboratory experiments with a simple single structure morphology porous medium (plus conventional approximation of effective constant coefficients).

Among many possible extensions and improvements of existing models were consideration of specific soil types and specific morphology, lower level scale fluctuations of variables, cross-effects of different variable fluctuations, phase and interface variable fluctuations effects. The new integro-differential HSP-VAT transport equations for a heterogeneous soil and groundwater media and applications of these non-classical types of equations to underground systems were demonstrated using the few scale content of these systems. The results of a study of the feasibility of modeling the transport phenomena in a multiscale soil and contaminated groundwater system were reported to DOD ARPA. New mathematical models for nonlinear transport in different morphological pore systems were developed and are described. The methodology developed dealt with flow and solute modeling in a four scale soil systems.

There were firstly developed the main definitions and understanding of optimization problems in heterogeneous hierarchical media. Formulated optimization problem statements for - 1) Heat Exchangers; 2) Semiconductor Chip Heat Sinks. There are a number of traditional techniques applied to the optimization of heat transfer devices such as heat sink enhanced surfaces or heat exchangers. There are, however, no methods or mathematical studies devoted to optimization of hierarchical heat transfer devices. Design optimization procedures for transport in porous structures and enhanced heat transfer surfaces are formulated and developed.

Developed the first elements of statistical theory of design of experiments optimization (DOE) method for hierarchical transport problems. Ran the simulation experiments and obtained preliminary results. Obtained the results which allow supporting the statement about achievable the absolute upper limit of heat dissipation effectiveness on upper scale of VHDD in outlined morphological classes as, for example:

a) 2D longitudinal or transverse regular rib fins; or b) 3D transversely (cross flow) streamlined regularly located circular cross section arbitrary in 2D( x,z) pin fins; or c) 3D arbitrary shape regularly located pin fins; or d) 3D random location circular cross section arbitrary in 2D pin fins; etc.

The illustration was the method of hierarchical optimization of two- and three scale heat transport in a heterogeneous media of a semiconductor heat sink. It is shown how traditional governing equations developed using rigorous HSP-VAT methods can be used to optimize surface transport processes in support of heat transport technology. The difficulty in treating a multiparameter (more than 3 ) problem, even linear, known to be very difficult to overcome using a parameter sorting process. The combination of HSP-VAT based equations and the theory of statistical design was used to effectively begin treating 6D or 8D optimization volumes.

I would like to mention and this is important to stress out here that any HSP-VAT Two Scale problem solved was readily demonstrating the undetectable characteristics in comparison to the one scale model. I would like to make here the shorten list of advantageous features surfaced in only the one class of two scale HSP-VAT problems solved. The scaled heat transfer enhancing problems HSP-VAT formulation allowed to include and highlight the phenomena and features those are even not available to observe and they are not included into the conventional homogeneous simulating models. As among others:

a) the surficial transport (might take few percent of the overall rate), interface transport with exact description of its values via the morphology influence (might be in the range of 20 % and more);

b) interfield based heat transport (as driven by fluctuations in temperature and in fluid velocity, for example) might comprise the value of ~10 %;

c) nonlinearities in physical models and their coefficients interacting one with another, etc.;

d) the HSP-VAT based heat sink heat transfer parameters are vector and tensor variables, not conventional scalar ones, tied directly to the each phase performance.

Finally, I would like to talk about few new phenomena just recently surfaced and for those I see no other credible theoretical explanations and models as via the scaled approach. One of these events is the Negative Refractive Index Materials (Media) (NRIM) phenomenon experimental confirmation and simulation studies -

while another one is the collective behavior in the "sonofusion" generated phenomena including the nuclear reactions -

Our presentation had the size of about 6MB and can be available at special request.

and about experimental efforts related to scaled problems see more in

In 2007 Springer printed the book "Flow and Transport Processes with Complex Obstructions," NATO Science Series, II. Mathematics, Physics and Chemistry - Vol. 236, Springer, Dordrecht, (2007), edited by co-chairmen of that NATO Institute Gayev, Y.A. and Hunt, J.C.R.

There are 9 Chapters in the book, authored by presenters of the ASI. Browsing through the book and reviewing my notes in the above sub-sections I have found that the essence of my 2004 remarks are still valid. Most of authors were told to by me and emailed on that their models are obsolete and simply incorrect. Meanwhile, the texts in the book had been made with no sign of change to correct modeling in this field.

That means, of course, that this part of Fluid Mechanics science as it is done by conventional one-scale community OSFA (One Scale For All) is doomed to fade in disgrace. May be the next generation of professors be so brave to recognize "the historical feature of inhibition of apprehension, I ascribe the hypothesis of formation of inhibiting apprehension to what is called "hard wiring" of brain structure by cognitive scientists. People have suspected and taught for at least centuries that once one accepts a theory about rationalized phenomena, that the person can not implicitly understand another kind of theory about phenomena or develop it themselves, and for centuries more, people have believed that it is difficult for someone to change his ideas to accept a new idea;" - by Edward Lewis in his "The Periodic Production of Rationalized Phenomena and the Past Periodic Depressions"