1,721,045 research outputs found
Free surface CFD simulations of the flow around a planing plate
No full textA RANS ((Reynolds Averaged Navier Stokes)) free surface flow solver has been used to model the flow around a 2-D planing plate ((Fn = 1.596)). Calculations have been made for both the plate planing at the free surface and with the free surface approximated as a slip wall of prescribed form. Results for the lift force generated by the plate are presented and compared for the two methods. The results of the approximated free surface are found to be closer to empirical equations for flat plate lift than those where the free surface has been calculated. The work demonstrates the difficulties of accurately capturing a known flow using a volume of fluid ((VOF)) approach. However future enhancements should offer the ability to use such calculations for design
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
A novel method for identifying vortical structures
No full textA method for identifying vortices in a 2-D velocity field is developed. A function based on the local angles of velocity with respect to a datum is calculated at each point in the 2-D field. This function is a local minimum at vortex centres. An advanced statistical technique for identifying multiple minima is used to find the minima of this function. The method is used for vortices, calculated using a RANS CFD code (CFX 4.3), forming around a very large crude carrier (VLCC) and the results are seen to be close to the centres of the vortices
Variations 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
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