Monograph records
https://feeds.library.caltech.edu/people/McKeon-B-J/monograph.rss
A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenMon, 15 Apr 2024 23:54:46 +0000A model for "dynamic roughness" in turbulent channel flow
https://resolver.caltech.edu/CaltechAUTHORS:20141024-120928169
Authors: {'items': [{'id': 'McKeon-B-J', 'name': {'family': 'McKeon', 'given': 'B. J.'}, 'orcid': '0000-0003-4220-1583'}]}
Year: 2008
A simple model for roughness elements with a time-varying height was used to investigate the effect of time-dependent, "dynamic" roughness on wall-bounded flow. Temporally varying wall velocities were specified in a turbulent channel flow simulation in order
to model the effect of introducing a roughness time scale in addition to a distribution of
roughness length scales.https://authors.library.caltech.edu/records/5na8m-rq359Predicting structural and statistical features of wall turbulence
https://resolver.caltech.edu/CaltechAUTHORS:20180831-112140731
Authors: {'items': [{'id': 'McKeon-B-J', 'name': {'family': 'McKeon', 'given': 'B. J.'}, 'orcid': '0000-0003-4220-1583'}, {'id': 'Sharma-A-S', 'name': {'family': 'Sharma', 'given': 'A. S.'}, 'orcid': '0000-0002-7170-1627'}, {'id': 'Jacobi-I', 'name': {'family': 'Jacobi', 'given': 'I.'}}]}
Year: 2010
DOI: 10.48550/arXiv.1012.0426
The majority of practical flows, particularly those flows in applications of importance to transport, distribution and climate, are turbulent and as a result experience complex three-dimensional motion with increased drag compared with the smoother, laminar condition. In this study, we describe the development of a simple model that predicts important structural and scaling features of wall turbulence. We show that a simple linear superposition of modes derived from a forcing-response analysis of the Navier-Stokes equations can be used to reconcile certain key statistical and structural descriptions of wall turbulence. The computationally cheap approach explains and predicts vortical structures and velocity statistics of turbulent flows that have previously been identified only in experiments or by direct numerical simulation. In particular, we propose an economical explanation for the meandering appearance of very large scale motions observed in turbulent pipe flow, and likewise demonstrate that hairpin vortices are predicted by the model. This new capability has clear implications for modeling, simulation and control of a ubiquitous class of wall flows.https://authors.library.caltech.edu/records/a6d2n-1fm27Deconstructing wall turbulence - visualization of resolvent modes
https://resolver.caltech.edu/CaltechAUTHORS:20180831-112154414
Authors: {'items': [{'id': 'Barella-D', 'name': {'family': 'Barella', 'given': 'Daniel'}}, {'id': 'Churng-Sarah', 'name': {'family': 'Churng', 'given': 'Sarah'}}, {'id': 'Egan-C', 'name': {'family': 'Egan', 'given': 'Conrad'}}, {'id': 'Moarref-R', 'name': {'family': 'Moarref', 'given': 'Rashad'}}, {'id': 'Luhar-M', 'name': {'family': 'Luhar', 'given': 'Mitul'}}, {'id': 'Mushkin-H', 'name': {'family': 'Mushkin', 'given': 'Hillary'}}, {'id': 'Davidoff-S', 'name': {'family': 'Davidoff', 'given': 'Scott'}}, {'id': 'Hendrie-M', 'name': {'family': 'Hendrie', 'given': 'Maggie'}}, {'id': 'McKeon-B-J', 'name': {'family': 'McKeon', 'given': 'Beverley J.'}, 'orcid': '0000-0003-4220-1583'}]}
Year: 2013
DOI: 10.48550/arXiv.1310.2883
This article accompanies a fluid dynamics video entered into the Gallery of Fluid Motion of the 66th Annual Meeting of the APS Division of Fluid Dynamics.https://authors.library.caltech.edu/records/cfy1f-z7s32A foundation for analytical developments in the logarithmic region of turbulent channels
https://resolver.caltech.edu/CaltechAUTHORS:20180831-112157832
Authors: {'items': [{'id': 'Moarref-R', 'name': {'family': 'Moarref', 'given': 'Rashad'}}, {'id': 'Sharma-A-S', 'name': {'family': 'Sharma', 'given': 'Ati S.'}, 'orcid': '0000-0002-7170-1627'}, {'id': 'Tropp-J-A', 'name': {'family': 'Tropp', 'given': 'Joel A.'}, 'orcid': '0000-0003-1024-1791'}, {'id': 'McKeon-B-J', 'name': {'family': 'McKeon', 'given': 'Beverley J.'}, 'orcid': '0000-0003-4220-1583'}]}
Year: 2014
DOI: 10.48550/arXiv.1409.6047
An analytical framework for studying the logarithmic region of turbulent channels is formulated. We build on recent findings (Moarref et al., J. Fluid Mech., 734, 2013) that the velocity fluctuations in the logarithmic region can be decomposed into a weighted sum of geometrically self-similar resolvent modes. The resolvent modes and the weights represent the linear amplification mechanisms and the scaling influence of the nonlinear interactions in the Navier-Stokes equations (NSE), respectively (McKeon & Sharma, J. Fluid Mech., 658, 2010). Originating from the NSE, this framework provides an analytical support for Townsend's attached-eddy model. Our main result is that self-similarity enables order reduction in modeling the logarithmic region by establishing a quantitative link between the self-similar structures and the velocity spectra. Specifically, the energy intensities, the Reynolds stresses, and the energy budget are expressed in terms of the resolvent modes with speeds corresponding to the top of the logarithmic region. The weights of the triad modes -the modes that directly interact via the quadratic nonlinearity in the NSE- are coupled via the interaction coefficients that depend solely on the resolvent modes (McKeon et al., Phys. Fluids, 25, 2013). We use the hierarchies of self-similar modes in the logarithmic region to extend the notion of triad modes to triad hierarchies. It is shown that the interaction coefficients for the triad modes that belong to a triad hierarchy follow an exponential function. The combination of these findings can be used to better understand the dynamics and interaction of flow structures in the logarithmic region. The compatibility of the proposed model with theoretical and experimental results is further discussed.https://authors.library.caltech.edu/records/fskdj-8zn67Nonlinear forcing in the resolvent analysis of exact coherent states of the Navier-Stokes equations
https://resolver.caltech.edu/CaltechAUTHORS:20170731-084031416
Authors: {'items': [{'id': 'Rosenberg-Kevin-T', 'name': {'family': 'Rosenberg', 'given': 'Kevin'}}, {'id': 'McKeon-B-J', 'name': {'family': 'McKeon', 'given': 'Beverley J.'}, 'orcid': '0000-0003-4220-1583'}]}
Year: 2017
DOI: 10.48550/arXiv.1705.10824
The resolvent analysis of McKeon & Sharma (2010) recasts the Navier-Stokes equations into an input/output form in which the nonlinear term is treated as a forcing that acts upon the linear dynamics to yield a velocity response. The framework has shown promise with regards to producing low-dimensional representations of exact coherent states. Previous work has focused on a primitive variable output; here we show a velocity-vorticity formulation of the governing equations along with a Helmholtz decomposition of the nonlinear forcing term reveals a simplified input/output form in the resolvent analysis. This approach leads to an improved method for compact representations of exact coherent states for both forcing and response fields, with a significant reduction in degrees of freedom in comparison to the primitive variable approach.https://authors.library.caltech.edu/records/zdhg4-vfd25Influence of a local change of depth on the behavior of bouncing oil
drops
https://resolver.caltech.edu/CaltechAUTHORS:20180831-112151003
Authors: {'items': [{'id': 'Carmigniani-R-A', 'name': {'family': 'Carmigniani', 'given': 'Remi'}}, {'id': 'Lapointe-S', 'name': {'family': 'Lapointe', 'given': 'Simon'}, 'orcid': '0000-0003-2789-6540'}, {'id': 'Symon-S', 'name': {'family': 'Symon', 'given': 'Sean'}, 'orcid': '0000-0001-9085-0778'}, {'id': 'McKeon-B-J', 'name': {'family': 'McKeon', 'given': 'Beverley J.'}, 'orcid': '0000-0003-4220-1583'}]}
Year: 2018
DOI: 10.48550/arXiv.1310.2662
The work of Couder et al [1] (see also Bush et al [3, 4] inspired consideration of the impact of a submerged obstacle, providing a local change of depth, on the behavior of oil drops in the bouncing regime. In the linked videos, we recreate some of their results for a drop bouncing on a uniform depth bath of the same liquid undergoing vertical oscillations just below the conditions for Faraday instability, and show a range of new behaviors associated with change of depth.
This article accompanies a fluid dynamics video entered into the Gallery of Fluid Motion of the 66th Annual Meeting of the APS Division of Fluid Dynamics.https://authors.library.caltech.edu/records/p3v75-9pv92