1,721,019 research outputs found
Flow-induced noise of a wall-mounted finite airfoil at low-to-moderate Reynolds number
Full text linkAbstract not availableDanielle J.Moreau, Zebb Prime, Ric Porteous, Con J. Doolan, Vincent Valea
The effect of acoustic forcing on an airfoil tonal noise mechanism
No full textThe response of the boundary layer over an airfoil with cavity to external acoustic forcing, across a sweep of frequencies, was measured. The boundary layer downstream of the cavity trailing edge was found to respond strongly and selectively at the natural airfoil tonal frequencies. This is considered to be due to enhanced feedback. However, the shear layer upstream of the cavity trailing edge did not respond at these frequencies. These findings confirm that an aeroacoustic feedback loop exists between the airfoil trailing edge and a location near the cavity trailing edge.Karn L. Schumacher, Con J. Doolan, and Richard M. Kels
Aeolian tones generated by a square cylinder with a detached flat plate
No full textPaper number: AIAA-2011-2779The case of a rigid flat plate placed in the wake of a square cylinder for passive sound control is investigated numerically at a Reynolds number of 150 and a Mach number of 0.2. Two flow regimes are observed and these are shown to affect the radiated sound. An overall sound reduction at an observer directly above the cylinder is observed for small gap distance (G) between the cylinder and plate (0 ≤ G ≤ 2.3D, where D is the cylinder height), where a 2.9 dB reduction in sound pressure level is obtained when there is no gap between the two bodies. In contrast, the emitted sound pressure level increases by at least 8.0 dB for large gap distances (2.4D ≤ G ≤ 7D). Despite this, a 6.3 dB reduction in sound pressure level is obtained due to a sound cancellation mechanism when the plate length is reduced to 0.26D and placed 5.6D downstream of the cylinder. The maximum sound reduction attainable is shown to be limited by the non-linear unsteady stall process on the plate. © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.Mohamed Sukri Mat Ali, Con J. Doolan, Vincent Wheatle
Numerical evaluation and optimization of low speed wind tunnel contractions
No full textCon J. Doolan and Rick C. Morgan
Three-dimensional beamforming of dipolar aeroacoustic sources
No full textAbstract not availableRic Porteous, Zebb Prime, Con J. Doolan, Danielle J. Moreau, Vincent Valea
Improved Delayed Detached Eddy Simulation modeling and far-field trailing-edge noise estimation of a sharp-edged symmetric strut
No full textPatrick Marshallsay, Laura A. Brooks, Alex Cederholm, Con J. Doolan, Danielle J. Moreau and Cristobal Albarraci
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
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
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
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