Papers by Paul Manneville
CRC Press eBooks, Jul 12, 2017
Journal of Fluid Mechanics, Apr 28, 2016
An observed, spectacular and puzzling distinctive feature of wall-bounded flows transitioning to/... more An observed, spectacular and puzzling distinctive feature of wall-bounded flows transitioning to/from turbulence is the large-scale ordered coexistence of laminar and turbulent flow over a wide range of Reynolds numbers. In their article, Chantry et al. (J. Fluid Mech., vol. 791, 2016, R8) circumvent the problem of turbulence modulation in genuine plane Couette flow by replacing no-slip boundary conditions at the walls with effective stress-free conditions constraining the interior part of the flow only. In so doing, they are able to collect relevant information on the laminar-turbulent patterning. The approach is then adapted to plane Poiseuille and pipe flow, giving to it a more universal value. Taking advantage of the stress-free conditions, they derive reduced models efficient at capturing the laminar-turbulent coexistence. Such models would be useful to interpret recent findings in the large-aspect-ratio limit.
Journal De Physique, 1978
2014 Dans les nématiques, l'écoulement de cisaillement simple peut perdre sa stabilité lorsque le... more 2014 Dans les nématiques, l'écoulement de cisaillement simple peut perdre sa stabilité lorsque le directeur est perpendiculaire au plan de cisaillement. Ici nous étudions le régime non linéaire au-dessus du seuil de l'Instabilité Homogène [1]. Dans le cadre de la théorie de Frank, Ericksen et Leslie nous développons un calcul en perturbation partant des équations exactes et nous montrons que la bifurcation est continue : la distorsion croit comme la racine carrée de l'écart au seuil en accord quantitatif avec les expériences sur le MBBA. En ce qui concerne l'effet des fluctuations thermodynamiques, il n'apparait important que dans un voisinage extrêmement étroit du seuil d'instabilité. Abstract. 2014 In nematics, the simple shear flow may become unstable when the director is perpendicular to the shear plane. Here we study the non-linear regime above the threshold of the Homogeneous Instability [1]. We use a perturbative approach derived from exact equations within the framework of the Frank-Ericksen-Leslie continuous theory of nematics : the distortion grows as the square root of the distance to the threshold, in quantitative agreement with experiments on MBBA. Thermal fluctuation effects are also analysed. They turn out to be important only in a vanishingly narrow vicinity of the threshold.
HAL (Le Centre pour la Communication Scientifique Directe), 2005
IMPERIAL COLLEGE PRESS eBooks, Jul 1, 2010
Springer eBooks, 1974
Previous susceptibility measurements on the terbium and the holmium gallium garnets (TbGaG and Ho... more Previous susceptibility measurements on the terbium and the holmium gallium garnets (TbGaG and HoGaG) by Wolf et al 1 down to 1°K and by Cooke et al.2 down to 0.6°K indicated no magnetic ordering for these compounds. The results have been used in the case of TbGaG by Ayant et al 3 to evaluate the crystal-field splitting of the Tb3+ ion and they found two low-lying singlet energy levels well isolated from the upper ones with a separation of Δ = 4.2°K and a magnetic moment at saturation m s of 7.35µB. In the case of HoGaG, Onn and Meyer published specific heat measurements4 which are consistent with the same two-singlet scheme with Δ = 7.4°K.
NATO advanced study institutes series, 1995
ABSTRACT
HAL (Le Centre pour la Communication Scientifique Directe), Sep 1, 2009
Microfluidic techniques are employed to investigate air-liquid flows in the pulmonary airway tree... more Microfluidic techniques are employed to investigate air-liquid flows in the pulmonary airway tree. A network of microchannels with five generations is made and used as a simplified model of the pulmonary airway tree. Liquid plugs are injected into the network and pushed by air flow to divide at every bifurcation before reaching the exits. The resistance associated with the presence of one plug in a given generation is defined to establish a linear relation between the driving pressure and the total flow rate in the network. Based on this resistance, we have good predictions of the flow of two successive plugs in the network. For two-plug flows under the same driving pressure, the total flow rate depends not only on the lengths of the plugs but also the initial distance between the two. Strong long range interactions are found between daughter plugs, especially when they are flowing through the bifurcations. We also observe different flow patterns under different pushing conditions. Under a constant pressure forcing, the flow develops symmetrically while a constant flow rate push achieves an asymmetric flow.
HAL (Le Centre pour la Communication Scientifique Directe), Jul 18, 2011
International audienc
Hydrodynamics and Nonlinear Instabilities
ICP Fluid Mechanics, 2010
The study of low-dimensional dissipative dynamical systems has provided a reasonable understandin... more The study of low-dimensional dissipative dynamical systems has provided a reasonable understanding of the transition to temporal chaos in strongly confined systems for which the spatial structure can be considered as frozen. The situation is still less advanced for weakly confined systems where chaos has both a spatial and a temporal meaning. In order to approach the specificities of the latter, we have chosen to study first a partial differential equation (PDE) displaying a convective-type nonlinear term, steady cellular solutions as in convection, and a transition to spatiotemporal chaos, namely the damped Kuramoto-Sivashinsky (KS) equation:
HAL (Le Centre pour la Communication Scientifique Directe), 2005
HAL (Le Centre pour la Communication Scientifique Directe), 2005
IMPERIAL COLLEGE PRESS eBooks, Jul 1, 2010
I Information Theory and Statistical Physics.- Cellular Automata, Dynamics and Complexity.- Scali... more I Information Theory and Statistical Physics.- Cellular Automata, Dynamics and Complexity.- Scaling Properties of a Family of Transformations Defined on Cellular Automaton Rules.- Entropy and Correlations in Dynamical Lattice Systems.- Cellular Automata Probability Measures.- Complex Computing with Cellular Automata.- Phase Transitions of Two-State Probabilistic Cellular Automata with One Absorbing Phase.- Simulating the Ising Model on a Cellular Automaton.- Domain Growth Kinetics: Microscopic Derivation of the t1/2 Law.- Critical Behavior in Cellular Automata Models of Growth.- II Lattice Gas Theory and Direct Applications.- Deterministic Cellular Automata with Diffusive Behavior.- Cellular Automata Approach to Diffusion Problems.- Long-Time Decay of Velocity Autocorrelation Function of Two- Dimensional Lattice Gas Cellular Automata.- Evidence for Lagrangian Tails in a Lattice Gas.- The Construction of Efficient Collision Tables for Fluid Flow Computations with Cellular Automata.- Lattice Boltzmann Computing on the IBM 3090 Vector Multiprocessor.- Bibliography on Lattice Gases and Related Topics.- III Modeling of Microscopic Physical Processes.- Multi-species Lattice-Gas Automata for Realistic Fluid Dynamics.- Immiscible Lattice Gases: New Results, New Models.- Lattice Gas Simulation of 2-D Viscous Fingering.- Dynamics of Colloidal Dispersions via Lattice-Gas Models of an Incompressible Fluid.- Strings: A Cellular Automata Model of Moving Objects.- Cellular Automata Approach to Reaction-Diffusion Systems.- Simulation of Surface Reactions in Heterogeneous Catalysis: Sequential and Parallel Aspects.- IV Complex Macroscopic Behavior, Turbulence.- Periodic Orbits in a Coupled Map Lattice Model.- Phase Transitions in Convection Experiments.- Using Coupled Map Lattices to Unveil Structures in the Space of Cellular Automata.- V Design of Special-Purpose Computers.- A Cellular Automata Machine.- Index of Contributors.
arXiv (Cornell University), Apr 2, 2015
A system of simplified equations is proposed to govern the feedback interactions of large-scale f... more A system of simplified equations is proposed to govern the feedback interactions of large-scale flows present in laminar-turbulent patterns of transitional wall-bounded flows with small-scale Reynolds stresses generated by the self-sustainment process of turbulence, itself modeled using an extension of Waleffe's approach [5]. This text is the English adaptation of [18]. It is here complemented by an annex giving the detailed expression of the model alluded to above, absent from the French version due to space limitations. Large-scale back-flow around turbulent band fragments in PCF; see [3] for details.
HAL (Le Centre pour la Communication Scientifique Directe), Mar 14, 2012
International audienc
Uploads
Papers by Paul Manneville