The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
C. Boragno - One of the best experts on this subject based on the ideXlab platform.
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Flapping states of an Elastically anchored plate in a uniform flow with applications to energy harvesting by fluid-structure interaction
Physics of Fluids, 2013Co-Authors: Alessandro Orchini, Andrea Mazzino, Joel Guerrero, R. Festa, C. BoragnoAbstract:Linear stability analysis of an Elastically anchored flat plate in a uniform flow is investigated both analytically and numerically. The analytical formulation explicitly takes into account the effect of the wake on the plate by means of Theodorsen's theory. Three different parameters non-trivially rule the observed dynamics: mass density ratio between plate and fluid, Spring Elastic constant, and distance between the plate center of mass and the Spring anchor point on the plate. We found relationships between these parameters which rule the transition between stable equilibrium and fluttering. The shape of the resulting marginal curve has been successfully verified by high Reynolds number numerical simulations. Finally, the limiting case corresponding to a simply supported rigid rod is also analyzed and the resulting flapping instability traced back to a simple resonance condition. Our findings are of interest in applications related to energy harvesting by fluid-structure interaction, a problem that has recently attracted a great deal of attention. The main aim in that context is to identify the optimal physical/geometrical system configuration leading to large sustained motion, which is the source of energy one aims to extract.
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Flapping states of an el astically anchored wing in a uniform flow
arXiv: Fluid Dynamics, 2012Co-Authors: Alessandro Orchini, Andrea Mazzino, Joel Guerrero, R. Festa, C. BoragnoAbstract:Linear stability analysis of an Elastically anchored wing in a uniform flow is investigated both analytically and numerically. The analytical formulation explicitly takes into account the effect of the wake on the wing by means of Theodorsen's theory. Three different parameters non-trivially rule the observed dynamics: mass density ratio between wing and fluid, Spring Elastic constant and distance between the wing center of mass and the Spring anchor point on the wing. We found relationships between these parameters which rule the transition between stable equilibrium and fluttering. The shape of the resulting marginal curve has been successfully verified by high Reynolds number direct numerical simulations. Our findings are of interest in applications related to energy harvesting by fluid-structure interaction, a problem which has recently attracted a great deal of attention. The main aim in that context is to identify the optimal physical/geometrical system configuration leading to large sustained motion, which is the source of energy we aim to extract.
Klaus Schulten - One of the best experts on this subject based on the ideXlab platform.
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in search of the hair cell gating Spring Elastic properties of ankyrin and cadherin repeats
Structure, 2005Co-Authors: Marcos Sotomayor, David P Corey, Klaus SchultenAbstract:Summary Mechanotransduction in vertebrate hair cells involves a biophysically defined Elastic element (the "gating Spring") that pulls on the transduction channels. The tip link, a fine filament made of cadherin 23 linking adjacent stereocilia in hair-cell bundles, has been suggested to be the gating Spring. However, TRP channels that mediate mechanotransduction in Drosophila , zebrafish, and mice often have cytoplasmic domains containing a large number of ankyrin repeats that are also candidates for the gating Spring. We have explored the Elastic properties of cadherin and ankyrin repeats through molecular dynamics simulations using crystallographic structures of proteins with one cadherin repeat or 4 and 12 ankyrin repeats, and using models of 17 and 24 ankyrin repeats. The extension and stiffness of large ankyrin-repeat structures were found to match those predicted by the gating-Spring model. Our results suggest that ankyrin repeats of TRPA1 and TRPN1 channels serve as the gating Spring for mechanotransduction.
Leonid I. Slepyan - One of the best experts on this subject based on the ideXlab platform.
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Resonant waves in Elastic structured media: Dynamic homogenisation versus Green’s functions
International Journal of Solids and Structures, 2014Co-Authors: Alexander Movchan, Leonid I. SlepyanAbstract:We address an important issue of dynamic homogenisation in vector Elasticity for a doubly periodic mass-Spring Elastic lattice. The notion of logarithmically growing resonant waves is used in the analysis of star-shaped wave forms induced by an oscillating point force. We note that the dispersion surfaces for Floquet–Bloch waves in the Elastic lattice may contain critical points of the saddle type. Based on the local quadratic approximations of a dispersion surface, where the radian frequency is considered as a function of wave vector components, we deduce properties of a transient asymptotic solution associated with the contribution of the point source to the wave form. The notion of local Green’s functions is used to describe localised wave forms corresponding to the resonant frequency. The special feature of the problem is that, at the same resonant frequency, the Taylor quadratic approximations for different groups of the critical points on the dispersion surfaces (and hence different Floquet–Bloch vectors) are different. Thus, it is shown that for the vector case of micro-structured Elastic medium there is no uniformly defined dynamic homogenisation procedure for a given resonant frequency. Instead, the continuous approximation of the wave field can be obtained through the asymptotic analysis of the lattice Green’s functions, presented in this paper.
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Resonant waves in Elastic structured media: dynamic homogenisation versus Green's functions
arXiv: Analysis of PDEs, 2013Co-Authors: Alexander Movchan, Leonid I. SlepyanAbstract:We address an important issue of a dynamic homogenisation in vector Elasticity for a doubly periodic mass-Spring Elastic lattice. The notion of logarithmically growing resonant waves is used in a complete analysis of star-shaped wave forms induced by an oscillating point force. We note that the dispersion surfaces for Floquet-Bloch waves in an Elastic lattice main contain critical points of the saddle type. Based on the local quadratic approximations of the frequency, as a function of wave vector components, we deduce properties of a transient asymptotic solution as the contribution of the point source to the wave form. In this way, we describe local Green's functions as localized wave forms corresponding to the resonant frequency. The peculiarity of the problem lies in the fact that, at the same resonant frequency, the Taylor quadratic approximations for different groups of the resonant points are different, and hence we deal with different local Green's functions. Thus, there is no uniformly defined homogenisation procedure for a given resonant frequency. Instead, the continuous approximation of the wave field can be obtained through the asymptotic analysis of the lattice Green's functions.
Alessandro Orchini - One of the best experts on this subject based on the ideXlab platform.
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Flapping states of an Elastically anchored plate in a uniform flow with applications to energy harvesting by fluid-structure interaction
Physics of Fluids, 2013Co-Authors: Alessandro Orchini, Andrea Mazzino, Joel Guerrero, R. Festa, C. BoragnoAbstract:Linear stability analysis of an Elastically anchored flat plate in a uniform flow is investigated both analytically and numerically. The analytical formulation explicitly takes into account the effect of the wake on the plate by means of Theodorsen's theory. Three different parameters non-trivially rule the observed dynamics: mass density ratio between plate and fluid, Spring Elastic constant, and distance between the plate center of mass and the Spring anchor point on the plate. We found relationships between these parameters which rule the transition between stable equilibrium and fluttering. The shape of the resulting marginal curve has been successfully verified by high Reynolds number numerical simulations. Finally, the limiting case corresponding to a simply supported rigid rod is also analyzed and the resulting flapping instability traced back to a simple resonance condition. Our findings are of interest in applications related to energy harvesting by fluid-structure interaction, a problem that has recently attracted a great deal of attention. The main aim in that context is to identify the optimal physical/geometrical system configuration leading to large sustained motion, which is the source of energy one aims to extract.
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Flapping states of an el astically anchored wing in a uniform flow
arXiv: Fluid Dynamics, 2012Co-Authors: Alessandro Orchini, Andrea Mazzino, Joel Guerrero, R. Festa, C. BoragnoAbstract:Linear stability analysis of an Elastically anchored wing in a uniform flow is investigated both analytically and numerically. The analytical formulation explicitly takes into account the effect of the wake on the wing by means of Theodorsen's theory. Three different parameters non-trivially rule the observed dynamics: mass density ratio between wing and fluid, Spring Elastic constant and distance between the wing center of mass and the Spring anchor point on the wing. We found relationships between these parameters which rule the transition between stable equilibrium and fluttering. The shape of the resulting marginal curve has been successfully verified by high Reynolds number direct numerical simulations. Our findings are of interest in applications related to energy harvesting by fluid-structure interaction, a problem which has recently attracted a great deal of attention. The main aim in that context is to identify the optimal physical/geometrical system configuration leading to large sustained motion, which is the source of energy we aim to extract.
Marcos Sotomayor - One of the best experts on this subject based on the ideXlab platform.
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in search of the hair cell gating Spring Elastic properties of ankyrin and cadherin repeats
Structure, 2005Co-Authors: Marcos Sotomayor, David P Corey, Klaus SchultenAbstract:Summary Mechanotransduction in vertebrate hair cells involves a biophysically defined Elastic element (the "gating Spring") that pulls on the transduction channels. The tip link, a fine filament made of cadherin 23 linking adjacent stereocilia in hair-cell bundles, has been suggested to be the gating Spring. However, TRP channels that mediate mechanotransduction in Drosophila , zebrafish, and mice often have cytoplasmic domains containing a large number of ankyrin repeats that are also candidates for the gating Spring. We have explored the Elastic properties of cadherin and ankyrin repeats through molecular dynamics simulations using crystallographic structures of proteins with one cadherin repeat or 4 and 12 ankyrin repeats, and using models of 17 and 24 ankyrin repeats. The extension and stiffness of large ankyrin-repeat structures were found to match those predicted by the gating-Spring model. Our results suggest that ankyrin repeats of TRPA1 and TRPN1 channels serve as the gating Spring for mechanotransduction.