1,721,185 research outputs found
Turbulent separation in lower curved wall channels
No full textTurbulent boundary layer separation in channels with a lower curved wall is studied using direct numerical simulations (DNS). Turbulence dynamics are studied through classical statistical tools such as the turbulent kinetic energy budget for varying lower curved wall dimensions. The geometry features are expected to have a significant effect on the fluid flow structures and the characteristic scales of separation. The separation bubble behind the bump is studied in terms of its size, turbulent kinetic energy production mechanisms and transfer and scale-by-scale energy budget. New innovative data-analysis techniques will be used based on the generalisation of the Kolmogorov equation to anisotropic and spatially non-homogeneous flow configurations
Esaltare la tipicità del Gewürztraminer con l’utilizzo di specifici lieviti inattivati in vigneto
No full textTurbulence modulation in particle laden homogeneous shear flow: Exact Regularized Point Particle method
No full textThis contribution presents a first evaluation of a new approach, dubbed the Exact Regularized Point Particle (ERPP) method [Gualtieri et al., Exact regularized point particle method for multi-phase flows in the two-way coupling regime, arXiv preprint arXiv:1405.6969], designed to model the modulation of turbulence by hundred thousands of small inertial particles. The approach overcomes some intrinsic difficulties which arise in some circumstances in available approaches like, e.g., the Particle In Cell (PIC) method introduced by Crowe and coworkers since 1977. Numerical results concerning a homogeneous shear flow at moderate values of the Reynolds number laden with hundred thousand of small inertial particles are discussed documenting the turbulence modification in the so-called two-way coupling regime, in a range of control parameters unaccessible to the available approaches
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Turbulence modulation in particle laden pipe flow: Exact regularized point particle method
No full textMany technological applications are characterized by turbulent bounded flows with dispersed particles. For high mass load (particle/fluid mass ratio) a significant inter-phase momentum exchange occurs (two-way coupling regime), inducing a significant alteration of the turbulent field which, in turn, modifies the dynamics of the suspended phase. Aim of the present study is exploring the potentially of recently developed momentum coupling method, dubbed the Exact Regularized Point Particle (ERPP) method, in reproducing via Direct Numerical Simulation (DNS) the detailed dynamics of a particles laden turbulent pipe flow. The comparison with available experimental and numerical data confirms the ability of the new approach in reproducing the relevant dynamics also in parameter ranges which are unaccessible to standard techniques
Are observational studies more informative than randomized controlled trials in hypertension?: Con side of the argument
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Experiments and DNS of a round jet with turbulent inlet
No full textExperimental and Direct Numerical Simulation data of a turbulent round jet fed by a turbulent pipe are compared in the near field. The Reynolds number achieved in both the experiment and the simulation, Re = 16000, allows a direct comparison of both the average and the fluctuating velocity statistics. In the experiments the jet is fed with olive oil droplets with a Stokes number St ' 1 whose dynamics is compared against the corresponding DNS simulation to asses the ability of particles to reproduce high order turbulence statistics and to asses the accumulation properties of inertial particles in the near field
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