NUMERICAL MODELING OF THE COAGULATION AND POROSITY EVOLUTION OF DUST AGGREGATES

Okuzumi, Satoshi; Sakagami, Masa-aki; Tanaka, Hidekazu

doi:10.1088/0004-637X/707/2/1247

Title: NUMERICAL MODELING OF THE COAGULATION AND POROSITY EVOLUTION OF DUST AGGREGATES

Full Record
Other Related Research

Abstract

Porosity evolution of dust aggregates is crucial in understanding dust evolution in protoplanetary disks. In this study, we present useful tools to study the coagulation and porosity evolution of dust aggregates. First, we present a new numerical method for simulating dust coagulation and porosity evolution as an extension of the conventional Smoluchowski equation. This method follows the evolution of the mean porosity for each aggregate mass simultaneously with the evolution of the mass distribution function. This method reproduces the results of previous Monte Carlo simulations with much less computational expense. Second, we propose a new collision model for porous dust aggregates on the basis of our N-body experiments on aggregate collisions. As the first step, we focus on 'hit-and-stick' collisions, which involve neither compression nor fragmentation of aggregates. We first obtain empirical data on porosity changes between the classical limits of ballistic cluster-cluster and particle-cluster aggregation. Using the data, we construct a recipe for the porosity change due to general hit-and-stick collisions as well as formulae for the aerodynamical and collisional cross sections. Our collision model is thus more realistic than a previous model of Ormel et al. based on the classical aggregation limits only. Simple coagulation simulations using themore »« less

Authors:

Okuzumi, Satoshi; Sakagami, Masa-aki ^[1]; Tanaka, Hidekazu ^[2]

Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501 (Japan)
Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan)

Publication Date:: Sun Dec 20 00:00:00 EST 2009

OSTI Identifier:: 21392574

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal

Additional Journal Information:: Journal Volume: 707; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/707/2/1247; Journal ID: ISSN 0004-637X

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; AGGLOMERATION; COLLISIONS; COMPUTERIZED SIMULATION; CROSS SECTIONS; DUSTS; EQUATIONS; FRACTALS; FRAGMENTATION; GRAVITATION; MASS; MASS DISTRIBUTION; MONTE CARLO METHOD; POROSITY; POROUS MATERIALS; PROTOPLANETS; CALCULATION METHODS; DISTRIBUTION; MATERIALS; SIMULATION; SPATIAL DISTRIBUTION

Citation Formats


                    Okuzumi, Satoshi, Sakagami, Masa-aki, and Tanaka, Hidekazu. NUMERICAL MODELING OF THE COAGULATION AND POROSITY EVOLUTION OF DUST AGGREGATES.  United States: N. p., 2009. 
        Web.  doi:10.1088/0004-637X/707/2/1247.

Copy to clipboard


                    Okuzumi, Satoshi, Sakagami, Masa-aki, & Tanaka, Hidekazu. NUMERICAL MODELING OF THE COAGULATION AND POROSITY EVOLUTION OF DUST AGGREGATES.  United States.  https://doi.org/10.1088/0004-637X/707/2/1247

Copy to clipboard


                    Okuzumi, Satoshi, Sakagami, Masa-aki, and Tanaka, Hidekazu. 2009.  
        "NUMERICAL MODELING OF THE COAGULATION AND POROSITY EVOLUTION OF DUST AGGREGATES".  United States.  https://doi.org/10.1088/0004-637X/707/2/1247.

Copy to clipboard


                    
@article{osti_21392574,

  title        = {NUMERICAL MODELING OF THE COAGULATION AND POROSITY EVOLUTION OF DUST AGGREGATES},

  author       = {Okuzumi, Satoshi and Sakagami, Masa-aki and Tanaka, Hidekazu},

  abstractNote = {Porosity evolution of dust aggregates is crucial in understanding dust evolution in protoplanetary disks. In this study, we present useful tools to study the coagulation and porosity evolution of dust aggregates. First, we present a new numerical method for simulating dust coagulation and porosity evolution as an extension of the conventional Smoluchowski equation. This method follows the evolution of the mean porosity for each aggregate mass simultaneously with the evolution of the mass distribution function. This method reproduces the results of previous Monte Carlo simulations with much less computational expense. Second, we propose a new collision model for porous dust aggregates on the basis of our N-body experiments on aggregate collisions. As the first step, we focus on 'hit-and-stick' collisions, which involve neither compression nor fragmentation of aggregates. We first obtain empirical data on porosity changes between the classical limits of ballistic cluster-cluster and particle-cluster aggregation. Using the data, we construct a recipe for the porosity change due to general hit-and-stick collisions as well as formulae for the aerodynamical and collisional cross sections. Our collision model is thus more realistic than a previous model of Ormel et al. based on the classical aggregation limits only. Simple coagulation simulations using the extended Smoluchowski method show that our collision model explains the fractal dimensions of porous aggregates observed in a full N-body simulation and a laboratory experiment. By contrast, similar simulations using the collision model of Ormel et al. result in much less porous aggregates, meaning that this model underestimates the porosity increase upon unequal-sized collisions. Besides, we discover that aggregates at the high-mass end of the distribution can have a considerably small aerodynamical cross section per unit mass compared with aggregates of lower masses. This occurs when aggregates drift under uniform acceleration (e.g., gravity) and their collision is induced by the difference in their terminal velocities. We point out an important implication of this discovery for dust growth in protoplanetary disks.},

  doi          = {10.1088/0004-637X/707/2/1247},

  url          = {https://www.osti.gov/biblio/21392574},
  journal      = {Astrophysical Journal},

  issn         = {0004-637X},

  number       = 2,

  volume       = 707,

  place        = {United States},

  year         = {Sun Dec 20 00:00:00 EST 2009},

  month        = {Sun Dec 20 00:00:00 EST 2009}

}

Copy to clipboard

Journal Article:

https://doi.org/10.1088/0004-637X/707/2/1247

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

RAPID COAGULATION OF POROUS DUST AGGREGATES OUTSIDE THE SNOW LINE: A PATHWAY TO SUCCESSFUL ICY PLANETESIMAL FORMATION

Journal Article Okuzumi, Satoshi; Kobayashi, Hiroshi; Tanaka, Hidekazu; ... - Astrophysical Journal

Rapid orbital drift of macroscopic dust particles is one of the major obstacles to planetesimal formation in protoplanetary disks. We re-examine this problem by considering the porosity evolution of dust aggregates. We apply a porosity model based on recent N-body simulations of aggregate collisions, which allows us to study the porosity change upon collision for a wide range of impact energies. As a first step, we neglect collisional fragmentation and instead focus on dust evolution outside the snow line, where the fragmentation has been suggested to be less significant than inside the snow line because of the high sticking efficiencymore »« less
https://doi.org/10.1088/0004-637X/752/2/106
ELECTROSTATIC BARRIER AGAINST DUST GROWTH IN PROTOPLANETARY DISKS. I. CLASSIFYING THE EVOLUTION OF SIZE DISTRIBUTION

Journal Article Okuzumi, Satoshi; Sakagami, Masa-aki; Tanaka, Hidekazu; ... - Astrophysical Journal

Collisional growth of submicron-sized dust grains into macroscopic aggregates is the first step of planet formation in protoplanetary disks. These grains are expected to carry nonzero negative charges in the weakly ionized disks, but its effect on their collisional growth has not been fully understood so far. In this paper, we investigate how the charging affects the evolution of the dust size distribution properly taking into account the charging mechanism in a weakly ionized gas as well as porosity evolution through low-energy collisions. To clarify the role of the size distribution, we divide our analysis into two steps. First, wemore »« less
https://doi.org/10.1088/0004-637X/731/2/95
Including Dust Coagulation in Hydrodynamic Models of Protoplanetary Disks: Dust Evolution in the Vicinity of a Jupiter-mass Planet

Journal Article Dra̧żkowska, Joanna; Li, Shengtai; Birnstiel, Til; ... - The Astrophysical Journal (Online)

Dust growth is often neglected when building models of protoplanetary disks due to its complexity and computational expense. However, it does play a major role in shaping the evolution of protoplanetary dust and planet formation. In this paper, we present a numerical model coupling 2D hydrodynamic evolution of a protoplanetary disk, including a Jupiter-mass planet, and dust coagulation. This is obtained by including multiple dust fluids in a single grid-based hydrodynamic simulation and solving the Smoluchowski equation for dust coagulation on top of solving for the hydrodynamic evolution. We find that fragmentation of dust aggregates trapped in a pressure bumpmore »« less
https://doi.org/10.3847/1538-4357/ab46b7

Full Text Available
ELECTRIC CHARGING OF DUST AGGREGATES AND ITS EFFECT ON DUST COAGULATION IN PROTOPLANETARY DISKS

Journal Article Okuzumi, Satoshi - Astrophysical Journal

Mutual sticking of dust aggregates is the first step toward planetesimal formation in protoplanetary disks. In spite that the electric charging of dust particles is well recognized in some contexts, it has been largely ignored in the current modeling of dust coagulation. In this study, we present a general analysis of the dust charge state in protoplanetary disks, and then demonstrate how the electric charging could dramatically change the currently accepted scenario of dust coagulation. First, we describe a new semianalytical method to calculate the dust charge state and gas ionization state self-consistently. This method is far more efficient thanmore »« less
https://doi.org/10.1088/0004-637X/698/2/1122; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)
LOW-VELOCITY COLLISIONS OF CENTIMETER-SIZED DUST AGGREGATES

Journal Article Beitz, E; Guettler, C; Blum, J; ... - Astrophysical Journal

Collisions between centimeter- and decimeter-sized dusty bodies are important in understanding the mechanisms leading to the formation of planetesimals. We performed laboratory experiments to study the collisional behavior of dust aggregates in this size range at velocities below and around the fragmentation threshold. We developed two independent experimental setups with the same goal: to study the effects of bouncing, fragmentation, and mass transfer in free particle-particle collisions. The first setup is an evacuated drop tower with a free-fall height of 1.5 m, providing us with 0.56 s of microgravity time, so that we observed collisions with velocities between 8 mmmore »« less
https://doi.org/10.1088/0004-637X/736/1/34

Similar Records