Registered Data

[CT147]

[00096] Multi-scale analysis of concentration distribution inside porous medium channel configuration

  • Session Date & Time : 5D (Aug.25, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : A multiple-scale perturbation analysis is presented for the two-dimensional concentration distribution of passive contaminant released in an incompressible viscous fluid channel filled with a porous medium. The flow is driven by the combined effect of the upper plate oscillation and the periodic pressure gradient. Homogenization technique is used to find the concentration distribution up to third order. For a fixed amplitude of oscillation and pulsation, frequency of pressure pulsation has stronger effect on the dispersion.
  • Classification : 76M50, 76R99, 76S99
  • Author(s) :
    • Timir Karmakar (Department of Mathematics, National Institute of Technology Meghalaya, Shillong, Meghalaya 793003)
    • Swarup Barik (2Department of Mathematics, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203)
    • Raja Sekhar G P (Indian Institute of Technology Kharagpur India)

[00878] Large-amplitude problem of BGK model

  • Session Date & Time : 5D (Aug.25, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : BGK equation is a relaxation model of the Boltzmann equation for simulation of various kinetic flow problems. In this work, we study asymptotic stability of the BGK model when the initial data is not necessarily close to global equilibrium pointwisely. Main difficulty of the BGK equation comes from the highly nonlinear structure of the relaxation operator. To overcomes this issue, we derive refined control of macroscopic fields to guarantee the system enters quadratic nonlinear regime.
  • Classification : 76P05, 35B35, 35B40, 82C40
  • Author(s) :
    • Gichan Bae (Seoul National University)
    • Gyounghun Ko (POSTECH)
    • donghyun lee (POSTECH)
    • Seokbae Yun (Sungkyunkwan University)

[00990] BGK model for two-component gases near a global Maxwellian

  • Session Date & Time : 5D (Aug.25, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : In this talk, we establish the existence of the unique global-in-time classical solutions to the two-component BGK model when the initial data is a small perturbation of global equilibrium. The main difference between this model compared to the classic mixture Boltzmann equation is that the rate of interchange of momentum and energy between the two species is controllable through two free parameters. Based on the energy method, we carefully analyze the dissipative nature of the linearized multi-component relaxation operator and observe that the partial dissipation from the intra-species and the inter-species linearized relaxation operators are combined in a complementary manner to give rise to the desired dissipation estimate of the model. Furthermore, the dissipation estimate depends on the momentum interchange rate and the energy interchange rate. So the larger interchange rate leads to stronger dissipation, and therefore, faster convergence to the global equilibrium. This is joint work with C. Klingenberg, M. Pirner, and S.-B. Yun.
  • Classification : 76P05, 46N55, 82C40, 35F25
  • Author(s) :
    • Gi-Chan Bae (Seoul National University)
    • Christian Klingenberg (Würzburg University)
    • Marlies Pirner (Würzburg University)
    • Seok-Bae Yun (Sungkyunkwan University)

[02049] A Hybrid AMR Low-Rank Tensor Approach for Solving the Boltzmann Equation

  • Session Date & Time : 5D (Aug.25, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : Computational complexity grows exponentially in a grid-based approach to modeling the Boltzmann equation as dimensionality increases. Scalable low-rank tensor decomposition techniques have been developed to mitigate such issues, but challenges remain when applying real-world boundary conditions in engineering systems with complex geometries. To address these challenges, we propose a novel hybrid algorithm where quad-tree adaptive mesh refinement (AMR) is applied in real space while a low-rank approximation is used in velocity space.
  • Classification : 76P05, 35Q83, 65M50
  • Author(s) :
    • Samuel Jun Araki (Jacobs Technology Inc. / Air Force Research Laboratory)

[00946] Escape kinetics of self-propelled particle from a circular cavity

  • Session Date & Time : 5D (Aug.25, 15:30-17:10)
  • Type : Contributed Talk
  • Abstract : We numerically investigate the mean exit time of self-propelled Janus particle from a circular cavity with single or multiple exit windows. Our simulation results witness distinct escape mechanisms depending upon the relative amplitudes of the thermal length and self-propulsion length compared to the cavity and pore sizes. We show that the exit rate can be maximized for an optimal self-propulsion persistence length, which depends on the damping strength, self-propulsion velocity, and cavity size.
  • Classification : 82-10, 82C05, 82C31
  • Author(s) :
    • Tanwi Debnath (University of Calcutta)