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Related papers: Caustic activation of rain showers

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We present a mean-field model that describes droplet growth due to condensation and collisions and droplet loss due to fallout. The model allows for an effective numerical simulation. We study how the rain initiation time depends on…

Atmospheric and Oceanic Physics · Physics 2007-05-23 G. Falkovich , M. G. Stepanov , M. Vucelja

We present a series of numerical studies of the interaction of colliding radiative, hydrodynamic young stellar outflows. We study the effect of the collision impact parameter on the acceleration of ambient material and the degree to which…

Astrophysics · Physics 2008-11-26 Andrew J. Cunningham , Adam Frank , Eric G. Blackman

The term "solid-state turbulence" may sound like an oxymoron, but in fact it is not. In this article we demonstrate that solid-state turbulence may emerge owing to a defining property of the solid state: the ability of a solid to retain its…

Fluid Dynamics · Physics 2021-11-10 Y. Beygelzimer , A. E. Filippov , R. Kulagin , Y. Estrin

We discuss the probability distribution of relative speed $\Delta V$ of inertial particles suspended in a highly turbulent gas when the Stokes numbers, a dimensionless measure of their inertia, is large. We identify a mechanism giving rise…

Fluid Dynamics · Physics 2009-11-13 K. Gustavsson , B. Mehlig , M. Wilkinson , V. Uski

This article presents direct numerical simulations of the growth of turbulent spots in the transitional regime of plane Couette flow. A quantitative description of the growth process and of the detail of the quadrupolar flow around the spot…

Fluid Dynamics · Physics 2014-01-16 Joran Rolland

We study the formation of caustics in vortex-dominated \flows. We \find that only particles starting within a critical distance of a vortex which scales as the square roots of the particle inertia and the circulation can form sling…

Fluid Dynamics · Physics 2015-06-24 S. Ravichandran , Rama Govindarajan

The observed rapid onset of star formation in molecular clouds requires rapid formation of dense fragments which can collapse individually before being overtaken by global gravitationally-driven flows. Many previous investigations have…

Astrophysics · Physics 2009-11-13 F. Heitsch , L. Hartmann , A. Burkert , ;

The inner parsec of our Galaxy contains tens of Wolf-Rayet stars whose powerful outflows are constantly interacting while filling the region with hot, diffuse plasma. Theoretical models have shown that, in some cases, the collision of…

We investigate the effect of turbulence on the collisional growth of um-sized droplets through high- resolution numerical simulations with well resolved Kolmogorov scales, assuming a collision and coalescence efficiency of unity. The…

Atmospheric and Oceanic Physics · Physics 2019-01-14 Xiang-Yu Li , A. Brandenburg , G. Svensson , N. E. L. Haugen , B. Mehlig , I. Rogachevskii

Turbulent thermal diffusion is a combined effect of the temperature stratified turbulence and inertia of small particles. It causes the appearance of a non-diffusive turbulent flux of particles in the direction of the turbulent heat flux.…

Fluid Dynamics · Physics 2018-05-24 G. Amir , N. Bar , A. Eidelman , T. Elperin , N. Kleeorin , I. Rogachevskii

The influence of clustering on the collision rate of inertial particles in a smooth random velocity field, mimicking the smaller scales of a turbulent flow, is analyzed. For small values of the the ratio between the relaxation time of the…

Statistical Mechanics · Physics 2009-11-13 Piero Olla

A simple theory, based on observations of snowflake distribution in a turbulent flow, is proposed to model the growth of inertial particles as a result of dynamic clustering at scales larger than the Kolmogorov length scale. Particles able…

Fluid Dynamics · Physics 2015-10-16 Michele Guala , Jiarong Hong

Inertial particles in turbulent flows are characterised by preferential concentration and segregation and, at sufficient mass loading, dense particle clusters may spontaneously arise due to momentum coupling between the phases. These…

Fluid Dynamics · Physics 2019-01-30 Alessio Innocenti , Rodney O Fox , Sergio Chibbaro

In this paper, a mathematical model of two adjacent rigid particles immersed into a viscous incompressible fluid is considered. The main feature of the flow is that the Cauchy stress tensor consisting of the strain tensor and the pressure…

Analysis of PDEs · Mathematics 2022-05-24 Zhiwen Zhao

To trigger precipitation, water droplets in warm clouds need to attain a sufficient size. Theoretical estimates based on condensation and gravitational collisions alone fail to explain the observed timescales for the onset of precipitation…

Fluid Dynamics · Physics 2026-02-25 Tobias Bätge , Johannes Zierenberg , Michael Wilczek

The Stokes wave problem in a constant vorticity flow is formulated, by virtue of conformal mapping techniques, as a nonlinear pseudodifferential equation, involving the periodic Hilbert transform, which becomes the Babenko equation in the…

Fluid Dynamics · Physics 2019-10-23 Sergey A. Dyachenko , Vera Mikyoung Hur

The use of simplified models of turbulent flows provides an appealing possibility to study the collision rate of turbulent suspensions, especially in conditions relevant to astrophysics, which require large time scale separations. To check…

Fluid Dynamics · Physics 2016-04-06 Michel Voßkuhle , Alain Pumir , Emmanuel Lévêque , Michael Wilkinson

We investigate the effects of condensation and liquid water loading on the stably stratified surface layer, with an eye towards understanding the influence of turbulent mixing on fog formation. Direct numerical simulations (DNS) of dry and…

Fluid Dynamics · Physics 2020-12-09 Michael MacDonald , Marcin J. Kurowski , João Teixeira

Tropical regions may experience periodic extreme precipitation and suffer from associated periodic deluges in a warmer climate. Recent studies conducted small-domain (around 100 km x 100 km) atmospheric model simulations and found that…

Atmospheric and Oceanic Physics · Physics 2025-11-26 Heng Quan , Yi Zhang , Guy Dagan , Stephan Fueglistaler

This paper discusses the evolution of the droplet size distribution for a liquid-in-gas aerosol contained in a Rayleigh-B\'enard cell. It introduces a non-collisional model for broadening the droplet size distribution, termed 'convective…

Atmospheric and Oceanic Physics · Physics 2015-06-22 Michael Wilkinson