# Latest papers in fluid mechanics

### Self-similarity and coarsening rate of a convecting bicontinuous phase separating mixture: Effect of the viscosity contrast

Author(s): Hervé Henry and György Tegze

A computational study shows that the viscosity contrast between the two phases of a multiphase fluid induces noticeable morphological changes to the geometry of the two phases during self-similar coarsening. Quantitative measures are specified.

[Phys. Rev. Fluids 3, 074306] Published Mon Jul 30, 2018

### Thin or bulky: Optimal aspect ratios for ship hulls

Author(s): Jean-Philippe Boucher, Romain Labbé, Christophe Clanet, and Michael Benzaquen

We present a minimal approach to address the problem of ship hull optimization, and compare our theoretical results with existing data. We show that optimal hull aspect ratios result from a subtle balance between wave drag, pressure drag, and skin friction.

[Phys. Rev. Fluids 3, 074802] Published Mon Jul 30, 2018

### Spatial characterization of turbulent channel flow via complex networks

Author(s): G. Iacobello, S. Scarsoglio, J. G. M. Kuerten, and L. Ridolfi

A network-based analysis of a turbulent channel flow numerically solved at Reτ=180 is proposed as an innovative perspective for the spatial characterization of the flow field. Two spatial networks corresponding to the streamwise and wall-normal velocity components are built, where nodes represent po...

[Phys. Rev. E 98, 013107] Published Fri Jul 27, 2018

### Cavitation in a liquid-filled cavity surrounded by an elastic medium: Intercoupling of cavitation events in neighboring cavities

Author(s): Alexander A. Doinikov, Benjamin Dollet, and Philippe Marmottant

The subject of the present theoretical study is the dynamics of a cavitation bubble in a spherical liquid-filled cavity surrounded by an infinite elastic solid. Two objectives are pursued. The first is to derive equations for the velocity and pressure fields throughout the liquid filling the cavity ...

[Phys. Rev. E 98, 013108] Published Fri Jul 27, 2018

### Gas-kinetic simulation of sustained turbulence in minimal Couette flow

Author(s): M. A. Gallis, J. R. Torczynski, N. P. Bitter, T. P. Koehler, S. J. Plimpton, and G. Papadakis

Simulations of a gas in a Minimal Couette unit at Re=500 using Direct Simulation Monte Carlo, a molecular method enforcing molecular chaos for gas-molecule collisions, reproduces the turbulence from DNS. Thus molecular chaos does not prevent development of long-range correlations in turbulence.

[Phys. Rev. Fluids 3, 071402(R)] Published Thu Jul 26, 2018

### Static and dynamic fluid-driven fracturing of adhered elastica

Author(s): Thomasina V. Ball and Jerome A. Neufeld

Transient spreading of a viscous fluid beneath an adhered elastic sheet is controlled by the tip dynamics. Spreading occurs in two dynamical regimes: viscosity dominant and adhesion dominant. Experiments with elastic sheets made of PDMS confirm these regimes and the emergence of a vapor tip.

[Phys. Rev. Fluids 3, 074101] Published Thu Jul 26, 2018

### Spectral energy scaling in precessing turbulence

Author(s): A. Khlifi, A. Salhi, S. Nasraoui, F. Godeferd, and C. Cambon

We study precessing turbulence, which appears in several geophysical and astrophysical systems, by direct numerical simulations of homogeneous turbulence where precessional instability is triggered due to the imposed background flow. We show that the time development of kinetic energy K occurs in tw...

[Phys. Rev. E 98, 011102(R)] Published Wed Jul 25, 2018

### Oscillatory solutothermal convection-driven evaporation kinetics in colloidal nanoparticle-surfactant complex fluid pendant droplets

Author(s): A. R. Harikrishnan, Purbarun Dhar, Sateesh Gedupudi, and Sarit K. Das

Evaporation kinetics of surfactant-infused nanocolloidal droplets are studied using the pendant mode to understand the pure physics of evaporation in such complex fluids. Oscillatory solute-thermal convective currents are found to be responsible for evaporation rate enhancement in these complex fluids.

[Phys. Rev. Fluids 3, 073604] Published Wed Jul 25, 2018

### Particle-to-fluid heat transfer in particle-laden turbulence

Author(s): Hadi Pouransari and Ali Mani

We analyze heat transfer between disperse and carrier phases in multiphase turbulent flows. We reduce the full characterization of the problem to two parameters: Stokes number based on large eddy time, and a dimensionless number indicating the ratio of gas thermal relaxation time to large eddy time.

[Phys. Rev. Fluids 3, 074304] Published Wed Jul 25, 2018

### Estimating stable and unstable sets and their role as transport barriers in stochastic flows

Author(s): Sanjeeva Balasuriya and Georg A. Gottwald

We consider the situation of a large-scale stationary flow subjected to small-scale fluctuations. Assuming that the stable and unstable manifolds of the large-scale flow are known, we quantify the mean behavior and stochastic fluctuations of particles close to the unperturbed stable and unstable man...

[Phys. Rev. E 98, 013106] Published Tue Jul 24, 2018

### Koopman analysis of Burgers equation

Author(s): Jacob Page and Rich R. Kerswell

A full Koopman decomposition for the velocity field in the Burgers equation is presented by deriving explicit expressions for the Koopman modes and eigenfunctions.

[Phys. Rev. Fluids 3, 071901(R)] Published Tue Jul 24, 2018