The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform

S. A. Isaev - One of the best experts on this subject based on the ideXlab platform.

P. A. Baranov - One of the best experts on this subject based on the ideXlab platform.

Sanjoy Banerjee - One of the best experts on this subject based on the ideXlab platform.

  • Generalized lattice Boltzmann equation with forcing term for computation of wall-bounded turbulent flows.
    Physical review. E Statistical nonlinear and soft matter physics, 2009
    Co-Authors: Kannan N Premnath, Martin J Pattison, Sanjoy Banerjee
    Abstract:

    In this paper, we present a framework based on the generalized lattice Boltzmann equation (GLBE) using multiple relaxation times with forcing term for eddy capturing simulation of wall-bounded turbulent flows. Due to its flexibility in using disparate relaxation times, the GLBE is well suited to maintaining numerical stability on coarser grids and in obtaining improved solution fidelity of near-wall turbulent fluctuations. The subgrid scale (SGS) turbulence effects are represented by the standard Smagorinsky eddy viscosity model, which is modified by using the van Driest wall-damping function to account for reduction of turbulent length scales near walls. In order to be able to simulate a wider class of problems, we introduce forcing terms, which can represent the effects of general nonuniform forms of forces, in the natural moment space of the GLBE. Expressions for the strain rate tensor used in the SGS model are derived in terms of the nonequilibrium moments of the GLBE to include such forcing terms, which comprise a generalization of those presented in a recent work [Yu, Comput. Fluids 35, 957 (2006)]. Variable resolutions are introduced into this extended GLBE framework through a conservative Multiblock Approach. The Approach, whose optimized implementation is also discussed, is assessed for two canonical flow problems bounded by walls, viz., fully developed turbulent channel flow at a shear or friction Reynolds number (Re) of 183.6 based on the channel half-width and three-dimensional (3D) shear-driven flows in a cubical cavity at a Re of 12 000 based on the side length of the cavity. Comparisons of detailed computed near-wall turbulent flow structure, given in terms of various turbulence statistics, with available data, including those from direct numerical simulations (DNS) and experiments showed good agreement. The GLBE Approach also exhibited markedly better stability characteristics and avoided spurious near-wall turbulent fluctuations on coarser grids when compared with the single-relaxation-time (SRT)-based Approach. Moreover, its implementation showed excellent parallel scalability on a large parallel cluster with over a thousand processors.

  • Generalized lattice Boltzmann equation with forcing term for computation of wall-bounded turbulent flows.
    Physical Review E, 2009
    Co-Authors: Kannan N Premnath, Martin J Pattison, Sanjoy Banerjee
    Abstract:

    In this paper, we present a framework based on the generalized lattice Boltzmann equation (GLBE) using multiple relaxation times with forcing term for eddy capturing simulation of wall-bounded turbulent flows. Due to its flexibility in using disparate relaxation times, the GLBE is well suited to maintaining numerical stability on coarser grids and in obtaining improved solution fidelity of near-wall turbulent fluctuations. The subgrid scale (SGS) turbulence effects are represented by the standard Smagorinsky eddy viscosity model, which is modified by using the van Driest wall-damping function to account for reduction of turbulent length scales near walls. In order to be able to simulate a wider class of problems, we introduce forcing terms, which can represent the effects of general nonuniform forms of forces, in the natural moment space of the GLBE. Expressions for the strain rate tensor used in the SGS model are derived in terms of the nonequilibrium moments of the GLBE to include such forcing terms, which comprise a generalization of those presented in a recent work [Yu et al., Comput. Fluids 35, 957 (2006)]. Variable resolutions are introduced into this extended GLBE framework through a conservative Multiblock Approach. The Approach, whose optimized implementation is also discussed, is assessed for two canonical flow problems bounded by walls, viz., fully developed turbulent channel flow at a shear or friction Reynolds number (Re) of 183.6 based on the channel half-width and three-dimensional (3D) shear-driven flows in a cubical cavity at a Re of 12 000 based on the side length of the cavity. Comparisons of detailed computed near-wall turbulent flow structure, given in terms of various turbulence statistics, with available data, including those from direct numerical simulations (DNS) and experiments showed good agreement. The GLBE Approach also exhibited markedly better stability characteristics and avoided spurious near-wall turbulent fluctuations on coarser grids when compared with the single-relaxation-time (SRT)-based Approach. Moreover, its implementation showed excellent parallel scalability on a large parallel cluster with over a thousand processors.

A. E. Usachov - One of the best experts on this subject based on the ideXlab platform.

Elisabeth Guichard - One of the best experts on this subject based on the ideXlab platform.

  • Statistical Multiblock Approach on Oral Processing parameters, in vivo aroma release and perception
    2014
    Co-Authors: Elisabeth Guichard, Charfedinne Ayed, El Mostafa Qannari, Philippe Courcoux, Hélène Labouré, Gilles Feron
    Abstract:

    Statistical Multiblock Approach on Oral Processing parameters, in vivo aroma release and perception. 3. international conference on Food oral processing: physics, physiology and psychology of eating

  • Understanding aroma release from model cheeses by a statistical Multiblock Approach on oral processing.
    PloS one, 2014
    Co-Authors: Gilles Feron, Charfedinne Ayed, El Mostafa Qannari, Philippe Courcoux, Hélène Labouré, Elisabeth Guichard
    Abstract:

    For human beings, the mouth is the first organ to perceive food and the different signalling events associated to food breakdown. These events are very complex and as such, their description necessitates combining different data sets. This study proposed an integrated Approach to understand the relative contribution of main food oral processing events involved in aroma release during cheese consumption. In vivo aroma release was monitored on forty eight subjects who were asked to eat four different model cheeses varying in fat content and firmness and flavoured with ethyl propanoate and nonan-2-one. A Multiblock partial least square regression was performed to explain aroma release from the different physiological data sets (masticatory behaviour, bolus rheology, saliva composition and flux, mouth coating and bolus moistening). This statistical Approach was relevant to point out that aroma release was mostly explained by masticatory behaviour whatever the cheese and the aroma, with a specific influence of mean amplitude on aroma release after swallowing. Aroma release from the firmer cheeses was explained mainly by bolus rheology. The persistence of hydrophobic compounds in the breath was mainly explained by bolus spreadability, in close relation with bolus moistening. Resting saliva poorly contributed to the analysis whereas the composition of stimulated saliva was negatively correlated with aroma release and mostly for soft cheeses, when significant.