Anomalous Dispersion Particle tracking velocimetry and image processing for classical and non-classical dispersion theories J. Ramirez, T. Weinstein, S. Harrington, K. Bardsley, Y. Wu, A. Cagnioncle and L. Donado John Cushman, Monica Moroni and Natalie Kleinfenter Anomalous Dispersion OUTLINE Introduction 1. • • • Mathematical Theory 2. • • 3. 4. Group 6 Experiments Objectives Image Processing Classical Dispersion Generalized Dispersion Data Analysis Summary & Conclusions Summer School in Geophysical Porous Media 2 Anomalous Dispersion Experimental Setup Group 6 Summer School in Geophysical Porous Media 3 Anomalous Dispersion Group 6 Objectives Other Questions • Determine if and when dispersion becomes Fickian (classical) using Particle Tracking Velocimetry (PTV) • Calculate the generalized dispersion coefficient • At what scale is the medium homogeneous? • At what scale is the medium heterogeneous? Summer School in Geophysical Porous Media 4 Anomalous Dispersion Original Photos Group 6 Summer School in Geophysical Porous Media 5 Anomalous Dispersion Filtered Noise Group 6 Summer School in Geophysical Porous Media 6 Anomalous Dispersion Final Image for Analyses Group 6 Summer School in Geophysical Porous Media 7 Anomalous Dispersion Centroid Tracking t3 t2 t1 toll t0 Dmax Group 6 Summer School in Geophysical Porous Media 8 Anomalous Dispersion Trajectories Group 6 Summer School in Geophysical Porous Media 9 Anomalous Dispersion OUTLINE Introduction 1. • • • Mathematical Theory 2. • • 3. 4. Group 6 Experiments Objectives Image Processing Classical Dispersion Generalized Dispersion Data Analysis Summary & Conclusions Summer School in Geophysical Porous Media 10 Anomalous Dispersion Lagrangian Description of Dispersion Posit ion and velocity at t ime t of a part icle init ially locat ed at x 0 X (t) = X (t; x 0 ) 2 ¡ µ R3 ; dX (t) V (t) = : dt Displacement s: Y (t) ´ X (t) ¡ X (0) Group 6 Summer School in Geophysical Porous Media 11 Anomalous Dispersion Two assumptions: T he mot ion of t he par t icl e is dict at ed by t -indep endent t r ansit ion pr obabilit ies f : Z P(X (t+ ¿) 2 A) = f (X (t); x; ¿) dx; for all t > 0 A Steady-state assumption hV (t)i = hV i Group 6 Stationarity (Homogeneity) Summer School in Geophysical Porous Media 12 Anomalous Dispersion Lagrangian Description of Dispersion Probability dist ribut ion of displacement s: Z t Y (t) = X (t; x 0 ) ¡ x 0 = V (s; x 0 ) ds 0 G(y; t) = P(Y (t) = y) = = h±(y ¡ (X (t) ¡ X (0)))i Z f (x 0 ; X (t); t) P(X (0) = x 0 ) dx 0 ¡ Group 6 Summer School in Geophysical Porous Media 13 Anomalous Dispersion Dispersion: Classical Approach Y (t) = hY i + Y 0(t); V (t) = hV i + V 0(t) Z t Y 0(t) = V 0(s; x 0 ) ds hY (t)i = hV i t; 0 dh(Y 0(t)) 2 i i dt ¿ = = À d (Y 0(t)) 2 = 2 hY 0(t)V 0(t)i i i dt i ¿Z À t 2 V 0(s)V 0(t) ds i Z = 2 i 0 t Z hV 0(s)V 0(t)i ds = 2 i i 0 Group 6 Summer School in Geophysical Porous Media 0 t CV 0 (s) ds i 14 Anomalous Dispersion dh(Y 0(t)) 2 i i = 2 dt Z t CV 0 (s) ds i 0 as t ! 0: h(Y 0(t)) 2 i ¼ htV 0(0) ¢tV 0(0)i = hV 02 i t 2 i as t ! i 1 : dh(Y 0(t)) 2 i i ¼2 dt Group 6 i Z 0 Fickian 1 CV 0 (s) ds ´ 2D i i i Summer School in Geophysical Porous Media 15 Anomalous Dispersion Non-Classical Approach: Generalized Dispersion Coefficient Dispersion \ at scale" k: dA(t) = i L A(t); dt A k (t) = ei k ¢X ( t ) ; ^ t) G(k; i L = V ¢r x = D E D ³ ´ ¤E WHAT DA…?: ei k ¢X ( t ) e¡ i k ¢X ( 0) = ei k ¢X ( t ) ei k ¢X ( 0) ´ CA (t) k Group 6 Summer School in Geophysical Porous Media 16 Anomalous Dispersion From project ion operat or t heory: t here exist s a m em or y ker nel K A such t hat , k dCA (t)¡ k = i hL A(0); A(0) ¤ i C A dt k Z t K^ A (¿) CA (t¡ ¿) d¿ 0 k k Z ^ t dG(k; t) ^ t) ¡ ^ t ¡ ¿) d¿ = i k ¢hV i G(k; K^ A (¿) G(k; dt k 0 Group 6 Summer School in Geophysical Porous Media 17 Anomalous Dispersion Generalized dispersion coe± cient : k ¢D^ (k; ¿) ¢k = K^ A (¿) k Let’s check it out… Z ^ t dG(k; t) ^ ^ = i k¢hV i G(k; t)¡ [k¢D^ (k; ¿)¢k] G(k; t¡ ¿) d¿ dt 0 Z Z t dG(x; t) = ¡ hV i ¢r G(x; t)+ r ¢ D (y; ¿)¢r G(x¡ y; t¡ ¿) dy d¿ dt 0 ¡ Group 6 Summer School in Geophysical Porous Media 18 Anomalous Dispersion ? Est imat ing K A = k ¢D^ (k; ¿) ¢k k Volt erra equat ion for K A k Z ^ ^ t 2G @ @ G K^ A (t) = ¡ (k; t) ¡ K^ A (t) (k; t ¡ ¿) d¿ @t2 @t k k 0 D ^ t) = ei k ¢X ( t ) e¡ G(k; Group 6 E i k ¢X ( 0) Summer School in Geophysical Porous Media From data 19 Anomalous Dispersion OUTLINE Introduction 1. • • • Mathematical Theory 2. • • 3. 4. Group 6 Experiments Objectives Image Processing Classical Dispersion Generalized Dispersion Data Analysis Summary & Conclusions Summer School in Geophysical Porous Media 20 Anomalous Dispersion Velocity Correlation coefficients in the transverse and longitudinal directions for two different mean velocities 1.2 1 Transverse Longitudinal 0.8 Transverse 0.6 Longitudinal 0.4 0.2 0 -0.2 1 3 5 7 9 11 13 15 17 19 21 -0.4 -0.6 Time lag (s) Group 6 Summer School in Geophysical Porous Media 21 Anomalous Dispersion Mean Velocity hV (t)i Transverse direction t 0 -0.01 0 5 10 15 20 25 -0.02 -0.03 -0.04 -0.05 v4 v2 -0.06 -0.07 Group 6 Summer School in Geophysical Porous Media 22 Anomalous Dispersion Correlation of velocity hV (t)V (t + ¿)i Transverse direction 0.12 0.10 0.08 V4 0.06 V2 0.04 ¿ 0.02 0.00 -0.02 0 5 10 15 20 -0.04 -0.06 Group 6 Summer School in Geophysical Porous Media 23 Anomalous Dispersion Displacement variance $\la (Y_z'(t))^2 \ra} 100 $ Longitudinal direction 10 t 1 1 0.1 Group 6 10 V2 V4 100 Variance of displacement Summer School in Geophysical Porous Media 24 Anomalous Dispersion Intermediate scattering function Transverse direction ^ ¿)) Re( G(k; k= 2¼ d increases 1.2 1 0.8 0.6 0.4 0.2 0 ¿ 1 Group 6 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 d=0.05 d=0.1 d=0.4 d=0.8 d=1.4 d=2.0 d=6.0 d=9.0 d=13.0 d=19.0 Summer School in Geophysical Porous Media 25 Anomalous Dispersion Intermediate scattering function ^ ¿)) I m( G(k; Transverse direction 0.08 0.06 0.04 0.02 ¿ 0 -0.02 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 -0.04 -0.06 d=0.05 d=6.0 Group 6 d=0.1 d=6.0 d=0.4 d=9.0 d=0.8 d=13.0 d=1.4 d=19.0 d=2.0 Summer School in Geophysical Porous Media d=2.0 d=2.0 26 Anomalous Dispersion Intermediate scattering function ^ ¿)) Re( G(k; Longitudinal direction 1.5 1 0.5 ¿ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 -0.5 -1 d=0.05 d=2.0 Group 6 d=0.1 d=6.0 d=0.4 d=9.0 d=0.8 d=13.0 Summer School in Geophysical Porous Media d=1.4 d=19.0 27 Anomalous Dispersion Intermediate scattering function ^ ¿)) I m( G(k; Longitudinal direction 1 0.8 0.6 0.4 0.2 ¿ 0 -0.2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 -0.4 -0.6 d=0.05 Group 6 d=0.1 d=0.4 d=0.8 d=1.4 d=2.0 d=6.0 Summer School in Geophysical Porous Media d=9.0 k= d=13.0 d=19.0 2¼ d 28 Anomalous Dispersion Generalized dispersion coefficient D^ x (k; ¿) Transversal direction 0.12 0.1 0.08 0.06 0.04 ¿ 0.02 0 -0.02 0 4 8 12 16 20 -0.04 -0.06 -0.08 k= -0.1 d=0.05 d=0.4 d=1.4 d=6.0 d=13.0 2¼ d Generalized dispersion tensor should equal to the velocity covariance in the Fickian limit. Group 6 Summer School in Geophysical Porous Media 29 Anomalous Dispersion Generalized dispersion tensor longitudinal direction D^ z (k; ¿) k= 2¼ d increases ¿ Group 6 Summer School in Geophysical Porous Media 30 Anomalous Dispersion OUTLINE Introduction 1. • • • Mathematical Theory 2. • • 3. 4. Group 6 Experiments Objectives Image Processing Classical Dispersion Generalized Dispersion Data Analysis Summary & Conclusions Summer School in Geophysical Porous Media 31 Anomalous Dispersion Summary & Conclusions • Examined a mathematical theory aimed at describing non-Fickian (anomalous) dispersion. • Analyzed experimental data to examine the mean, variances, classical and non-classical measures of dispersion. • From that analysis, we concluded that on the observed spatial scales the transport is anomalous even though the medium is homogeneous. • Other measures of dispersion are needed to describe anomalous dispersion. Group 6 Summer School in Geophysical Porous Media 32 Anomalous Dispersion 5. References Moroni M, Cushman JH Statistical mechanics with three-dimensional particle tracking velocimetry experiments in the study of anomalous dispersion. II. Experiments PHYSICS OF FLUIDS 13 (1): 81-91 JAN 2001 Cushman JH, Moroni M Statistical mechanics with three-dimensional particle tracking velocimetry experiments in the study of anomalous dispersion. I. Theory PHYSICS OF FLUIDS 13 (1): 75-80 JAN 2001 Moroni M, Cushman JH, Cenedese A A 3D-PTV two-projection study of pre-asymptotic dispersion in porous media which are heterogeneous on the bench scale INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE 41 (3-5): 337-370 FEB-MAR 2003 Monica Moroni, Natalie Kleinfelter and John H. Cushman Analysis of dispersion in porous media via matched-index particle tracking velocimetry experiments • ARTICLE ADVANCES IN WATER RESOURCES. In Press, Corrected Proof, Available online 31 March 2006 IGUCHI K STARTING METHOD FOR SOLVING NONLINEAR VOLTERRA INTEGRAL-EQUATIONS OF OF SECOND KIND COMMUNICATIONS OF THE ACM 15 (6): 460& 1972 Group 6 Summer School in Geophysical Porous Media 33 Anomalous Dispersion Questions?? Group 6 Summer School in Geophysical Porous Media 34
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