Article
Chemistry, Multidisciplinary
Jason P. Beech, Oskar E. Strom, Enrico Turato, Jonas O. Tegenfeldt
Summary: Solutions of macromolecules exhibit viscoelastic properties and may break time-reversal symmetry, resulting in elastic turbulence and wave variations. Altering the symmetry of individual pillars can influence the symmetry of waves and control instabilities and mixing in high-concentration DNA solutions.
Article
Physics, Applied
Victor Steinberg
Summary: This article briefly describes the main results of elastically driven instabilities and elastic turbulence in viscoelastic inertialess flows with curved streamlines. It then introduces a theory of elastic turbulence and predicts elastic waves based on the elastic stress, similar to Alfven waves in magneto-hydrodynamics. In contrast to other waves, the speed of these elastic waves depends on the medium's elasticity. The linear stability of parallel shear flows is discussed, along with recent developments in the parallel shear channel flow of polymer solutions. Elastically driven instabilities, elastic turbulence, elastic waves, and drag reduction are observed in this flow, contradicting linear stability predictions. The resistance of the flow, velocity and pressure fluctuations, coherent structures, and spectral properties of the velocity field are also briefly discussed as functions of the elasticity number.
LOW TEMPERATURE PHYSICS
(2022)
Article
Thermodynamics
S. Gupta, A. Chauhan, C. Sasmal
Summary: This study investigates the influence of adding solid polymers on mixed convective heat transfer phenomena. The results show that the addition of polymers can induce elastic instability and elastic turbulence, leading to an increase in heat transfer rate.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Multidisciplinary Sciences
Simon J. Haward, Cameron C. Hopkins, Amy Q. Shen
Summary: Research shows that introducing disorder into an ordered array of posts can promote chaotic fluctuations in viscoelastic flows through porous media, but the stability of pore geometry also depends on the nature of stagnation points exposed to the flow field.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Mechanics
A. Chauhan, S. Gupta, C. Sasmal
Summary: This study presents a numerical investigation of viscoelastic fluid flows in porous media. It is found that geometric disorder increases chaotic fluctuations in the flow, which is attributed to the formation of preferential paths and highly curved streamlines. The chaotic flow behavior is strongly influenced by the competition between strain-hardening and shear-thinning behaviors of the viscoelastic fluid.
Article
Multidisciplinary Sciences
Yuke Li, Victor Steinberg
Summary: Inertial-less viscoelastic channel flow exhibits a supercritical nonnormal mode elastic instability despite being linearly stable, due to finite-size perturbations. This elastic instability is caused by a direct transition from laminar to chaotic flow, rather than normal mode bifurcation. At higher velocities, elastic turbulence and further drag reduction flow regimes are observed, accompanied by elastic waves. These waves play a crucial role in amplifying wall-normal vorticity fluctuations through the transfer of energy from the mean flow, resulting in flow resistance and rotational vorticity fluctuations that depend linearly on the elastic wave energy.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Review
Mechanics
Hugo A. Castillo Sanchez, Mihailo R. Jovanovic, Satish Kumar, Alexander Morozov, V Shankar, Ganesh Subramanian, Helen J. Wilson
Summary: This review provides an overview of instabilities in shearing flows of viscoelastic fluids using the Oldroyd-B model. The review discusses the shortcomings of the model and suggests the use of more realistic constitutive models. Stability analysis tools and supporting evidence from experiments and simulations are also discussed.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2022)
Article
Thermodynamics
Haie Yang, Guice Yao, Dongsheng Wen
Summary: This study compares the occurrence and heat transfer effects of elastic turbulence in 3D, 2D, and 1D geometries. The results show that curvature is necessary for the onset of elastic turbulence in 1D geometry. Compared to 2D geometry, flow in 3D geometry achieves reduced pressure drop gradient and increased heat transfer.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Mechanics
V. Dzanic, C. S. From, A. Gupta, C. Xie, E. Sauret
Summary: This study numerically investigates the geometrical dependence of viscoelastic instabilities in geometrically complex applications where viscoelastic fluids naturally occur, such as porous media. The study demonstrates that the viscoelastic instability behavior is the same as previously reported in ideal pore geometries at low elasticity, but transitions into strong transient behavior at higher elasticity, with the most non-ideal pore geometry showing the strongest instability response.
Article
Mechanics
S. Migliozzi, L. Mazzei, P. Angeli
Summary: Elastic instabilities, occurring in the presence of low inertial effects, can significantly affect process efficiency in continuous flow laminar mixing applications. The impact on mixing patterns is strongly influenced by fluid elasticity and geometric characteristics.
Article
Materials Science, Multidisciplinary
Min Yang, Lin Shao, Jia-Ming Duan, Xiao-Tao Chen, Bi-Yu Tang
Summary: The mechanical properties of NbTiZrM alloys are closely correlated with valence electron concentration (VEC), with increasing VEC leading to higher single-crystal elastic parameters and elastic moduli. The alloys exhibit better ductility with lower VEC, as indicated by Poisson's ratio and Pugh's ratio. In addition, increasing VEC results in decreased elastic anisotropies and increased Debye temperatures in NbTiZrM alloys.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Engineering, Mechanical
Dominik Saile, Viktor Kuehl, Ali Guelhan
Summary: This study examines the impact of buffet/buffeting as a load-imposing mechanism on the base structures of space launcher, focusing on the varying excitation effects at different Mach numbers and the role of Reynolds stress distribution. Experiments conducted in a Vertical Test Section revealed a distinct excitation in the recirculation region, leading to the investigation of the mean shear layer reattachment at the tip of the nozzle.
EXPERIMENTS IN FLUIDS
(2021)
Article
Thermodynamics
Sara Taheripour, Mohammad Reza Saffarian, Noushin Azimy, Mehrsa Aghajari
Summary: This study investigates the heat transfer, friction factor, and thermal enhancement factor in a tube with different twisted-tape geometries. The findings show that triangular elements exhibit the most notable increase in Nusselt number compared to other shapes. Triangular elements also have the highest friction factor compared to square elements. The square with protrusions at 0 degrees has the maximum thermal enhancement factor, while the twist without elements has the lowest thermal enhancement factor.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Mechanics
Yue Wang, Jian-Ping Cheng, Hong-Na Zhang, Xin Zheng, Wei-Hua Cai, Dennis A. Siginer
Summary: This study investigates the effect of viscoelasticity on flow and heat transport in rectangular Rayleigh-Benard convection using direct numerical simulation. The results show that viscoelasticity weakly inhibits convection onset and transition from steady to oscillatory convection. Amplitude and frequency of oscillations in the flow regime are suppressed. Elastic nonlinearity creates irregular flow transitions and can cause convection cells to travel horizontally. Multiple pairs of roll flow patterns enhance heat transfer.
Article
Mechanics
Hideki Sato, Masaki Kawata, Ruri Hidema, Hiroshi Suzuki
Summary: This study visualized and quantified the characteristic flow behaviors of viscoelastic surfactant solutions in the cavity of a flow channel. The flow regimes were influenced by both inertia and elasticity, and the bulge structure was found to be a unique and promising flow regime for increasing heat transfer efficiency.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2022)
Article
Chemistry, Physical
Andrew M. Howe, Andrew Clarke, Jonathan Mitchell, John Staniland, Laurence Hawkes, Caroline WhalanAdvanced
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2015)
Article
Biochemical Research Methods
J. Mitchell, A. M. Howe, A. Clarke
JOURNAL OF MAGNETIC RESONANCE
(2015)
Article
Chemistry, Multidisciplinary
Paul D. I. Fletcher, Luke D. Savory, Freya Woods, Andrew Clarke, Andrew M. Howe
Article
Chemistry, Physical
Andrew Clarke, Andrew M. Howe, Jonathan Mitchell, John Staniland, Laurence Hawkes, Katherine Leeper
Article
Physics, Applied
H. Xu, A. Clarke, J. P. Rothstein, R. J. Poole
APPLIED PHYSICS LETTERS
(2016)
Article
Energy & Fuels
Paul D. I. Fletcher, Luke D. Savory, Andrew Clarke, Andrew M. Howe
Article
Chemistry, Physical
Jonathan Mitchell, Kyle Lyons, Andrew M. Howe, Andrew Clarke
Article
Chemistry, Physical
H. Xu, A. Clarke, J. P. Rothstein, R. J. Poole
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2018)
Article
Mechanics
E. J. Hemingway, A. Clarke, J. R. A. Pearson, S. M. Fielding
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2018)
Article
Mechanics
H. J. Barlowa, E. J. Hemingway, A. Clarke, S. M. Fielding
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2019)
Article
Mechanics
Enny Tran, Andrew Clarke
Summary: It is generally understood that the entanglement effects of viscoelastic polymer solutions are weakened under strong flow. However, recent research has found that high molecular weight HPAM solutions, which are entangled at use concentrations, exhibit a characteristic relaxation time when transitioning to elastic turbulence in porous flow. In this study, we directly measure the apparent characteristic relaxation time under shear using controlled-stress parallel-superposition background shear, and our results align with previous calculations using Rolie-poly and Rolie-double-poly models.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2023)
Article
Chemistry, Physical
Andrew Clarke, Elizabeth Jamie, Nikolaos A. Burger, Benoit Loppinet, George Petekidis
Summary: This study investigates the structural and mechanical changes of an oil-continuous drilling fluid formulation under high temperature and high pressure conditions using Diffusive Wave Spectroscopy (DWS). The results show that the drilling fluid undergoes local structural changes and exhibits strong hysteresis with temperature and pressure variations. Additionally, microrheology analysis is found to be consistent with direct rheological measurements at ambient pressure.
Article
Chemistry, Physical
Andrew Clarke
Summary: This study investigates the breakdown process of a gelled drilling fluid under the action of repeated deformation, suggesting that the fluid may behave as an arrested phase separating material. The observed evolution shows a maximum in elastic modulus correlated with a maximal connected heterogeneity of structure.
Proceedings Paper
Engineering, Electrical & Electronic
V. J. Anderson, A. Clarke, G. H. Meeten
Article
Chemistry, Physical
Yiping Yin, Zhe Wang, Hua Zou
Summary: This study presents a novel method for preparing dimpled polymer-silica nanocomposite particles using interfacial swelling-based seeded polymerization. The optimized conditions allow for a relatively high percentage of dimpled particles to be achieved.
Article
Chemistry, Physical
Brenden D. Hoehn, Elizabeth A. Kellstedt, Marc A. Hillmyer
Summary: Porous materials with nanometer-scale pores have important applications as nanoporous membranes. In this study, ABA triblock copolymers were used as precursors to produce nanoporous polymeric membranes (NPMs) in thin film form by degrading the end blocks. Polycyclooctene (PCOE) NPMs with tunable pore sizes were successfully prepared using solvent casting technique. Oxygen plasma etching was employed to improve the surface porosity and hydrophilicity of the membranes. This study provides a straightforward method to produce tough NPMs with high porosity and hydrophilic surface properties.
Article
Chemistry, Physical
Vladislav S. Petrovskii, Stepan I. Zholudev, Igor I. Potemkin
Summary: This article investigates the behavior of linear and ring polypeptide chains in aqueous solution and explores the properties of the complexes formed by these chains with oppositely charged surfactants. The results demonstrate that the complexes of linear supercharged unfolded polypeptides and the corresponding surfactants exhibit impressive adhesive properties.
Article
Chemistry, Physical
Merve Cevik, Serkan Dikici
Summary: Cardiovascular diseases are a leading cause of death globally, and vascular grafts are a promising treatment option. This study focuses on tissue-engineered vascular grafts (TEVGs) using decellularized parsley stems as a potential biomaterial. The decellularized parsley stems showed suitable properties for TEVGs, providing a suitable environment for human endothelial cells to form a pseudo endothelium. This study showcases the potential of using parsley stems for TEVGs.
Article
Chemistry, Physical
Gustavo A. Vasquez-Montoya, Tadej Emersic, Noe Atzin, Antonio Tavera-Vazquez, Ali Mozaffari, Rui Zhang, Orlando Guzman, Alexey Snezhko, Paul F. Nealey, Juan J. de Pablo
Summary: The optical properties of liquid crystals are typically controlled by electric fields. In this study, we investigate the effects of microfluidic flows and acoustic fields on the molecular orientation and optical response of nematic liquid crystals. We identify several previously unknown structures and explain them through calculations and simulations. These findings hold promise for the development of new systems combining sound, flow, and confinement.
Article
Chemistry, Physical
Xinjun Wu, Xin Guan, Shushu Chen, Jiangpeng Jia, Chongyi Chen, Jiawei Zhang, Chuanzhuang Zhao
Summary: This research presents a novel shape memory hydrogel with a remodelable permanent shape and programmable cold-induced shape recovery behavior. The hydrogel is prepared using specific treatment methods to achieve shape fixation by heating and shape recovery by cooling. Additionally, deformable devices can be obtained by assembling hydrogel blocks with different concentrations.
Article
Chemistry, Physical
Rebecca Hengsbach, Gerhard Fink, Ulrich Simon
Summary: This study examines the properties of DNA functionalized pNipmam microgels and pure pNipmam microgels at different concentrations of sodium chloride and in PBS solutions using temperature dependent H-1-NMR measurements. The results show that DNA modification affects the volume phase transition temperature and the addition of salt and PBS further enhances this effect.
Article
Chemistry, Physical
Ningyi Li, Junhong Li, Lijingting Qing, Shicheng Ma, Yao Li, Baohui Li
Summary: This paper investigates the self-assembly behavior of colloids with competing interactions under spherical confinement and finds that different ordered structures can be formed under different sized spherical confinements. Moreover, more perforated structures are formed in smaller spheres.
