Journal ArticleDOI
Analysis of a drag reduced flat plate turbulent boundary layer via uniform momentum zones
TLDR
In this article, the authors examined the connection between friction drag reduction and the structural properties of the instantaneous flow fields manipulated by the surface wave and found that the near-wall flow structures of high fluctuating intensity are less correlated to the large-scale uniform momentum zones (UMZs) due to the spanwise surface wave motion.About:
This article is published in Aerospace Science and Technology.The article was published on 2020-01-01. It has received 17 citations till now. The article focuses on the topics: Boundary layer & Drag.read more
Citations
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The Turbulent/Non-turbulent Interface and Entrainment in a Boundary Layer
TL;DR: In this paper, the turbulent/non-turbulent interface in a zero-pressure-gradient turbulent boundary layer at high Reynolds number was examined using particle image velocimetry.
Journal ArticleDOI
A review of turbulent skin-friction drag reduction by near-wall transverse forcing
TL;DR: In this paper, a review of active and passive control of turbulent near-wall layers to the imposition of unsteady and wavy transverse motion is presented, and a forward look towards possible future research and practical realizations is provided.
Journal ArticleDOI
Deep recurrent optical flow learning for particle image velocimetry data
TL;DR: A recurrent neural network-based approach for learning displacement fields in an end-to-end manner is applied to this technique and achieves state-of-the-art accuracy and allows generalization to new data, eliminating the need for traditional handcrafted models.
Journal ArticleDOI
Direct numerical simulations of supersonic turbulent boundary layer with streamwise-striped wall blowing
TL;DR: In this article, a spatially developing Ma 2.25 supersonic turbulent boundary layer with streamwise-striped wall blowing (SSB) is performed for the purpose of turbulence drag reduction.
Journal ArticleDOI
Lower drag and higher lift for turbulent airfoil flow by moving surfaces
Marian Albers,Wolfgang Schröder +1 more
TL;DR: In this paper, large-eddy simulations of the flow over an actuated NACA4412 airfoil at a chord-based Reynolds number Re c = 400, 000 are conducted.
References
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Journal ArticleDOI
Methods of Digital Video Microscopy for Colloidal Studies
John C. Crocker,David G. Grier +1 more
TL;DR: In this article, a set of image processing algorithms for extracting quantitative data from digitized video microscope images of colloidal suspensions is described, which can locate submicrometer spheres to within 10 nm in the focal plane and 150 nm in depth.
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Coherent Motions in the Turbulent Boundary Layer
TL;DR: In this paper, the role of coherent structures in the production and dissipation of turbulence in a boundary layer is characterized, summarizing the results of recent investigations, and diagrams and graphs are provided.
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Digital Particle Image Velocimetry
Christian Willert,Morteza Gharib +1 more
TL;DR: In this article, the directional ambiguity associated with PIV and LSV is resolved by implementing local spatial cross-correlations between two sequential single-exposed particle images, and the recovered velocity data are used to compute the spatial and temporal vorticity distribution and the circulation of the vortex ring.
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Vortex organization in the outer region of the turbulent boundary layer
TL;DR: In this paper, the structure of energy-containing turbulence in the outer region of a zero-pressure-gradient boundary layer has been studied using particle image velocimetry (PIV) to measure the instantaneous velocity fields in a streamwise-wall-normal plane.
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The autonomous cycle of near-wall turbulence
Javier Jiménez,Alfredo Pinelli +1 more
TL;DR: In this article, it is shown that a cycle exists which is local to the near-wall region and does not depend on the outer flow, and that the presence of the wall seems to be only necessary to maintain the mean shear.