Results 81 to 90 of about 208,538 (280)

Drag Reduction by Polymers in Wall Bounded Turbulence

, 2004
We address the mechanism of drag reduction by polymers in turbulent wall bounded flows. On the basis of the equations of fluid mechanics we present a quantitative derivation of the "maximum drag reduction (MDR) asymptote" which is the maximum drag ...
A. N. Beris, A. Rollin, B. A. Toms, M. J. Rudd, P. S. Virk, P. S. Virk, P.-G. de Gennes, R. B. Bird, S. B. Pope   +8 more
core   +1 more source

Rapid Fabrication of Self‐Propelled and Steerable Magnetic Microcatheters for Precision Medicine

Advanced Materials, EarlyView.
A rapid Joule heating fabrication method for the production of self‐propelling, adaptive microcatheters, with tunable stiffness and integrated microfluidic channels is presented. Demonstrated through three microrobotic designs, including a steerable guiding catheter, an untethered wave‐crawling TubeBot, and a distal‐end propelled microcatheter, it was ...
Zhi Chen, Boris Rivkin, David Castellanos‐Robles, Ivan Soldatov, Lukas Beyer, Mariana Medina‐Sánchez   +5 more
wiley   +1 more source

Experimental assessment of drag reduction by traveling waves in a turbulent pipe flow

, 2010
We experimentally assess the capabilities of an active, open-loop technique for drag reduction in turbulent wall flows recently introduced by Quadrio et al. [J. Fluid Mech., v.627, 161, (2009)].
A. Baron, F. Auteri, G. Campanardi, M. Belan, M. Quadrio, Okochi S., Quadrio M.   +6 more
core   +1 more source

Numerical simulation of turbulent duct flows with constant power input [PDF]

, 2014
The numerical simulation of a flow through a duct requires an externally specified forcing that makes the fluid flow against viscous friction. To this aim, it is customary to enforce a constant value for either the flow rate (CFR) or the pressure ...
Frohnapfel, Bettina, Hasegawa, Yosuke, Quadrio, Maurizio   +2 more
core   +2 more sources

Resolving Complex Multiscale Structure of Magneto‐ and Electroactive Polymer Composites With an Ionic Liquid

Advanced Materials, EarlyView.
Multiscale ionic liquid segregation into nano‐sized domains in the unconfined amorphous polymer phase and into micron‐sized pores enables a coupled magneto‐ and electroactive responses. ABSTRACT A multiscale understanding of the structure of ionogels – nanoparticle‐free polymer composites incorporating ionic liquids – is essential for enhancing their ...
Andrey Shibaev, Jon Maiz, Viktor Petrenko, Amaia Iturrospe, Josu Fernández Maestu, José María Porro, Mariano Barrado, Laura Casado, Joachim Kohlbrecher, Petr Shvets, Evgeny Modin, Ana Sofia Castro, Andrey Chuvilin, José María De Teresa, Daniela M. Correia, Arantxa Arbe, Senentxu Lanceros‐Méndez   +16 more
wiley   +1 more source

Molecular Dynamics Simulation of Stationary and Rotating Nanotube in Uniform Liquid Argon Flow [PDF]

, 2014
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the ...
4th Micro and Nano Flows Conference (MNF2014), Arabghanestany, M, Hasheminasab, SM, Hossein Karimian, SM   +3 more
core  

Colloquium: Theory of Drag Reduction by Polymers in Wall Bounded Turbulence [PDF]

, 2007
The flow of fluids in channels, pipes or ducts, as in any other wall-bounded flow (like water along the hulls of ships or air on airplanes) is hindered by a drag, which increases many-folds when the fluid flow turns from laminar to turbulent.
Bellakhel, G., Beris, A. N., Bird, R. B., de Gennes, P.-G., de Gennes, P.-G., Doi, M., Escudier, M. P., Flory, P. J., Gyr, A., Hoyt, J. W., Itamar Procaccia, Lamb, H., Landhal, M. T., L’vov, S. V., L’vov, V. S., McComb, W., Monin, A. S., Pope, S. B., Roberto Benzi, Toms, B. A., Victor S. L’vov, Yu, B.   +21 more
core   +1 more source

Liquid Metal Microrobots for Magnetically Guided Transvascular Navigation

Advanced Materials, EarlyView.
Liquid metal‐based microrobots combine magnetic steering, intrinsic X‐ray visibility and softness, to navigate blood vessels even against flow. Under clinically relevant magnetic fields, liquid metal microrobots roll along vessel walls, cross endothelial barriers, and accumulate in target tissues.
Xiaohui Ju, Roshan Velluvakandy, Xianghua Wu, Miguel Angel Merlos Rodrigo, Zbyněk Heger, Kamila Bendíčková, Jan Frič, Martin Pumera   +7 more
wiley   +1 more source

The Coupling of Ferroelectric Polarization and Oxygen Vacancy Migration Enables Electrically Controlled Thermal Memories

Advanced Materials, EarlyView.
Ferroelectric Hf0.5Zr0.5O2 epitaxial thin films exhibit a non‐volatile, electrically controlled thermal conductivity enabled by the coupling between oxygen vacancy migration, acting as phonon scatterers, and ferroelectric polarization, acting as ion migration valve.
Dídac Barneo, Miquel Royo, Rafael Ramos, Jesús Carrete, Hugo Romero‐Bernad, Ricardo Jiménez, Víctor Leborán, César Magén, Noa Varela‐Domínguez, Miguel Algueró, Riccardo Rurali, José A. Pardo, Francisco Rivadulla, Eric Langenberg   +13 more
wiley   +1 more source

A Mechanism of Polymer Induced Drag Reduction in Turbulent Pipe [PDF]

, 2014
Polymer induced drag reduction in turbulent pipe flow was investigated using a non-intrusive laser based diagnostic technique, namely Particle Image Velocimetry (PIV).
Markides, CN, Zadrazil, I
core   +1 more source