Comptes Rendus
Research article
The nonlocal nature of the Reynolds stress
Comptes Rendus. Mécanique, Volume 353 (2025), pp. 879-899

A nonlocal expression for the turbulent Reynolds stress $\overline{u^{\prime }v^{\prime }}$ solves in a unified manner for the velocity profiles in jets, shear layers, wakes, and boundary layers, offering predictions consistent with known measurements in these canonical flows. The framework is the random walk inspired closure of Prandtl (1925) since we write

\[ \overline{u^{\prime }v^{\prime }}=-\tilde{v}\ell \partial _y u \]

with $\ell $ a mean free path but, by contrast with Prandtl, with $\tilde{v}$ a nonlocal transfer velocity resulting from an integration over an appropriate portion of space of the mean velocity profile $u(y)$. The status of $\ell $ is discussed and its value, a fraction $(10\pi )^{-1}\approx 0.031$ of the integral scale, is computed in opened shear flows. The closure is adapted to the special case of boundary layers, where the value of the von Kármán constant is found to be $\kappa =6^{-1/2}\approx 0.41$.

Une expression non locale de la contrainte de Reynolds turbulente $\overline{u^{\prime }v^{\prime }}$ permet de résoudre de manière unifiée les profils de vitesse turbulents dans les jets, les couches de cisaillement, les sillages et les couches limites. Les prédictions sont cohérentes avec les mesures connues dans ces écoulements canoniques. Le cadre du raisonnement est inspiré de la fermeture de marche aléatoire de Prandtl (1925) puisque nous écrivons

\[ \overline{u^{\prime }v^{\prime }}=-\tilde{v}\ell \partial _y u \]

avec $\ell $ un libre parcours moyen mais, contrairement à Prandtl, avec $\tilde{v}$ une vitesse de transfert non locale résultant d’une intégration sur une portion appropriée de l’espace du profil de vitesse moyen $u(y)$. Le statut de $\ell $ est discuté et sa valeur, une fraction $(10\pi )^{-1}\approx 0,{\hspace{-0.55542pt}}031$ de l’échelle intégrale, est calculée dans les écoulements cisaillés ouverts. La fermeture est adaptée au cas particulier des couches limites, où la valeur de la constante de von Kármán est prédite comme valant $\kappa =6^{-1/2}\approx 0,{\hspace{-0.55542pt}}41$.

Received:
Accepted:
Published online:
DOI: 10.5802/crmeca.316
Keywords: Turbulence, Reynolds stress, closures
Mots-clés : Turbulence, contrainte de Reynolds, fermetures

Emmanuel Villermaux 1

1 Aix Marseille Université, CNRS, Centrale Marseille, IRPHE, Marseille, France
License: CC-BY 4.0
Copyrights: The authors retain unrestricted copyrights and publishing rights
@article{CRMECA_2025__353_G1_879_0,
     author = {Emmanuel Villermaux},
     title = {The nonlocal nature of the {Reynolds} stress},
     journal = {Comptes Rendus. M\'ecanique},
     pages = {879--899},
     year = {2025},
     publisher = {Acad\'emie des sciences, Paris},
     volume = {353},
     doi = {10.5802/crmeca.316},
     language = {en},
}
TY  - JOUR
AU  - Emmanuel Villermaux
TI  - The nonlocal nature of the Reynolds stress
JO  - Comptes Rendus. Mécanique
PY  - 2025
SP  - 879
EP  - 899
VL  - 353
PB  - Académie des sciences, Paris
DO  - 10.5802/crmeca.316
LA  - en
ID  - CRMECA_2025__353_G1_879_0
ER  - 
%0 Journal Article
%A Emmanuel Villermaux
%T The nonlocal nature of the Reynolds stress
%J Comptes Rendus. Mécanique
%D 2025
%P 879-899
%V 353
%I Académie des sciences, Paris
%R 10.5802/crmeca.316
%G en
%F CRMECA_2025__353_G1_879_0
Emmanuel Villermaux. The nonlocal nature of the Reynolds stress. Comptes Rendus. Mécanique, Volume 353 (2025), pp. 879-899. doi: 10.5802/crmeca.316

[1] O. Reynolds On the dynamical theory of incompressible viscous fluids and the determination of the criterion, Philos. Trans. R. Soc. Lond., Ser. A, Volume 186 (1895), pp. 123-164 | Zbl

[2] Stephen B. Pope Turbulent flows, Cambridge University Press, 2000, xxxiv+771 pages | DOI | MR | Zbl

[3] Pierre Sagaut; Claude Cambon Homogeneous turbulence dynamics, Springer, 2018, xxix+897 pages | MR | DOI | Zbl

[4] L. Prandtl Bericht über Untersuchungen zur ausgebildeten Turbulenz, Z. Angew. Math. Mech., Volume 5 (1925), pp. 136-139 | DOI | Zbl

[5] G. I. Taylor The transport of vorticity and heat through fluids in turbulent motion, Proc. R. Soc. Lond., Ser. A, Volume 135 (1932), pp. 685-705 | Zbl

[6] L. Rotily; P. Meunier; E. Villermaux Momentum, vorticity & scalar transport in turbulence: the Taylor–Prandtl controversy (2025) (To appear in J. Fluid Mech.)

[7] T. von Kármán Mechanische Ähnlichkeit und Turbulenz, Nachr. Ges. Wiss. Göttingen, Math.-Phys. Kl., Volume 1930 (1930), pp. 58-76 | Zbl

[8] Hermann Schlichting Boundary-layer theory, McGraw-Hill Series in Mechanical Engineering, McGraw-Hill, 1979, xxii+817 pages | Zbl | MR

[9] F. G. Schmitt About Boussinesq’s turbulent viscosity hypothesis: historical remarks and a direct evaluation of its validity, C. R. Méc., Volume 335 (2007), pp. 617-627 | Zbl | DOI

[10] Lev Davidovich Landau; Evgeniĭ Mikhaĭlovich Lifshits Fluid mechanics, Course of Theoretical Physics, 6, Pergamon Press, 1987, xiii+539 pages | Zbl

[11] I. Wygnansky; H. E. Fiedler Some measurements in the self-preserving jet, J. Fluid Mech., Volume 38 (1969) no. 3, pp. 577-612 | DOI

[12] L. Prandtl Bemerkungen zur Theorie der freien Turbulenz, Z. Angew. Math. Mech., Volume 22 (1942), pp. 241-243 | MR | Zbl | DOI

[13] I. Wygnansky; H. E. Fiedler The two-dimensional mixing region, J. Fluid Mech., Volume 41 (1970) no. 2, pp. 327-361 | DOI

[14] S. Corrsin Limitations of gradient transport models in random walks and in turbulence, Adv. Geophys., Volume 18 (1975) no. A, pp. 25-60 | DOI

[15] J. Boussinesq Essai sur la théorie des eaux courantes, Mémoires présentés par divers savants à l’Académie des Sciences de l’Institut de France, XXIII, Imprimerie nationale, 1877, 60 pages | Zbl

[16] P. Popovic; O. Devauchelle; E. Lejeunesse Momentum transfer across an open-channel, turbulent flow, J. Fluid Mech., Volume 981 (2024), A24 | DOI | MR | Zbl

[17] Max Born Atomic physics, Dover Books on Physics, Dover Publications, 1969, 495 pages

[18] D. B. Spalding Concentration fluctuations in a round turbulent free jet, Chem. Eng. Sci., Volume 26 (1971), pp. 95-107 | DOI

[19] B. H. Fiedler An integral closure model for the vertical turbulent flux of a scalar in a mixed layer, J. Atmos. Sci., Volume 41 (1984) no. 4, pp. 674-680 | DOI

[20] A. N. Souza; T. Lutz; G. R. Flierl Statistical nonlocality of dynamically coherent structures, J. Fluid Mech., Volume 966 (2023), A44 | DOI | MR | Zbl

[21] C. Josserand; M. Le Berre; Y. Pomeau Scaling laws in turbulence, Chaos, Volume 30 (2020), 073137 | DOI | MR | Zbl

[22] L. Bocquet; A. Colin; A. Ajdari Kinetic theory of plastic flow in soft glassy materials, Phys. Rev. Lett., Volume 103 (2009), 036001 | DOI

[23] M. Bouzid; M. Trulsson; P. Claudin; E. Clément; B. Andreotti Nonlocal rheology of granular flows across yield conditions, Phys. Rev. Lett., Volume 111 (2013), 238301 | DOI

[24] P. Kharel; P. Rognon Vortices enhance diffusion in dense granular flows, Phys. Rev. Lett., Volume 119 (2017), 178001 | DOI

[25] H. von Reichardt Impuls- und Warmeaustausch in freier Turbulenz, Z. Angew. Math. Mech., Volume 24 (1944) no. 5, pp. 268-272 | DOI | MR | Zbl

[26] J. C. Maxwell On the dynamical theory of gases, Phil. Mag. (4), Volume CLVII (1867) no. I, pp. 49-88 | DOI

[27] P. Salizzoni; S. Vaux; M. Creyssels; M. Amielh; L. Pietri; F. Anselmet Turbulent transfer and entrainment in a low-density jet, J. Fluid Mech., Volume 968 (2023), A27 | Zbl | DOI | MR

[28] Hermann Schlichting Laminare Strahlausbreitung, Z. Angew. Math. Mech., Volume 13 (1933) no. 4, pp. 260-263 | DOI | Zbl

[29] Lev Davidovich Landau A new exact solution of the Navier–Stokes equations, C. R. (Dokl.) Acad. Sci. URSS, n. Ser., Volume 43 (1944), pp. 286-288 | MR | Zbl

[30] D. Kristlanson; P. V. Danckwerts Studies in turbulent mixing I, Chem. Eng. Sci., Volume 16 (1961), pp. 267-277 | DOI

[31] R. M. C. So; B. C Hwang On similarity solutions for turbulent and heated round jets, Z. Angew. Math. Phys., Volume 37 (1986), pp. 624-631 | Zbl

[32] G. Kewalramani; B. Ji; Y. Dossmann; S. Becker; M. Gradeck; N. Rimbert A simple analytical model for turbulent kinetic energy dissipation for self-similar round turbulent jets, J. Fluid Mech., Volume 983 (2024), A44 | DOI | MR | Zbl

[33] T. Basset; B. Viggiano; T. Barois; M. Gibert; N. Mordant; R. B. Cal; R. Volk; M. Bourgoin Entrainment, diffusion and effective compressibility in a self-similar turbulent jet, J. Fluid Mech., Volume 947 (2022), A29 | DOI | MR

[34] W. Tollmien Berechnung turbulenter Ausbreitungsvorgange, Z. Angew. Math. Mech., Volume 6 (1926) no. 6, pp. 468-478 | DOI | Zbl

[35] P. Huerre; M. Rossi Hydrodynamic instabilities in open flows, Hydrodynamics and nonlinear instabilities (C. Godrèche; P. Manneville, eds.) (Collection Aléa-Saclay: Monographs and Texts in Statistical Physics), Volume 3, Cambridge University Press, 1998, pp. 81-294 | DOI | Zbl

[36] E. Villermaux Fragmentation versus cohesion, J. Fluid Mech., Volume 898 (2020), P1, 121 pages | DOI | MR | Zbl

[37] Lord Rayleigh On the stability, or instability of certain fluid motion, Proc. Lond. Math. Soc., Volume 11 (1880), pp. 57-72 | MR | Zbl

[38] M. Lesieur; C. Staquet; P. Le Roy; P. Comte The mixing layer and its coherence examined from the point of view of two-dimensional turbulence, J. Fluid Mech., Volume 192 (1988), pp. 511-534 | DOI | MR

[39] Peter J. Schmid; Dan S. Henningson Stability and transition in shear flows, Applied Mathematical Sciences, 142, Springer, 2001, xiv+556 pages | DOI | MR | Zbl

[40] L. Brown; A. Roshko On density effects and large scale structures in turbulent mixing layers, J. Fluid Mech., Volume 64 (1974) no. 4, pp. 775-815 | DOI

[41] R. Betchov; G. Szewczyk Stability of a shear layer between parallel streams, Phys. Fluids, Volume 6 (1963), pp. 1391-1395 | DOI | Zbl

[42] E. Villermaux On the role of viscosity in shear instabilities, Phys. Fluids, Volume 10 (1998), pp. 368-373 | DOI | MR | Zbl

[43] George Keith Batchelor The theory of homogeneous turbulence, Cambridge Monographs on Mechanics and Applied Mathematics, Cambridge University Press, 1959, xi+197 pages | MR

[44] R. Breidenthal Structure in turbulent mixing layers and wakes using a chemical reaction, J. Fluid Mech., Volume 109 (1981), pp. 1-24 | DOI

[45] P. E. Dimotakis The mixing transition in turbulent flows, J. Fluid Mech., Volume 409 (2000), pp. 69-98 | DOI | MR | Zbl

[46] S. Saddoughi; S. V. Veeravalli Local isotropy in turbulent boundary layers at high Reynolds number, J. Fluid Mech., Volume 268 (1994), pp. 333-372 | DOI

[47] E. Villermaux; J. Duplat Coarse grained scale of turbulent mixtures, Phys. Rev. Lett., Volume 97 (2006), 144506 | DOI

[48] A. A. Townsend The structure of turbulent shear flow, Cambridge Monographs on Mechanics and Applied Mathematics, Cambridge University Press, 1976, xi+429 pages | Zbl | MR

[49] X. I. A. Yang; I. Marusic; C. Meneveau Hierarchical random additive process and logarithmic scaling of generalized high order, two-point correlations in turbulent boundary layer flow, Phys. Rev. Fluids, Volume 1 (2016), 024402 | DOI

[50] J. C. Maxwell On the mathematical classification of physical quantities, Proc. Lond. Math. Soc., Volume III (1871) no. 34, pp. 224-233 | MR | Zbl

[51] G. T. Csanady Turbulent diffusion in the environment, Geophysics and Astrophysics Monographs, 3, Reidel Publishing Company, 1973, xii+249 pages | DOI

[52] James Dickson Murray Mathematical biology, Biomathematics (Berlin), 19, Springer, 1993, xiv+767 pages | MR | DOI | Zbl

[53] B. Dubrulle Log at first sight, J. Fluid Mech., Volume 1000 (2024), F6, 5 pages | DOI | MR

[54] B. J. McKeon Natural logarithms, J. Fluid Mech., Volume 718 (2013), pp. 1-4 | Zbl | DOI

Cited by Sources:

Comments - Policy