Using the immersed boundary method, we have simulated the motion of two flexible filaments in a flowing soap film, which was experimentally studied by Zhang et al. @Nature ~London! 408, 835 ~2000!#. We found numerically two distinct modes of sustained oscillation of the two filaments: parallel flapping and mirror-image clapping, depending on the separation distance between the two filaments. Ou...

Flow driven by pumping without valves is examined, motivated by biomedical applications: cardiopulmonary resuscitation (CPR) and the human fetus before the development of the heart valves. The direction of flow inside a loop of tubing which consists of (almost) rigid and flexible parts is investigated when the boundary of one end of the flexible segment is forced periodically in time. Despite t...

The goal of this work is to develop a numerical simulation that accurately captures the biomechanical response of bacterial biofilms and their associated extracellular matrix (ECM). In this, the second of a two-part effort, the primary focus is on formally presenting the heterogeneous rheology Immersed Boundary Method (hrIBM) and validating our model against experimental results. With this exte...

In this paper, we present an immersed boundary (IB) method to simulate a dry foam, i.e., a foam in which most of the volume is attributed to its gas phase. Dry foam dynamics involves the interaction between a gas and a collection of thin liquidfilm internal boundaries that partition the gas into discrete cells or bubbles. The liquid film boundaries are flexible, contract under the influence of ...

The objective of this paper is to present an overview of the newly proposed immersed continuum method in conjunction with the traditional treatment of fluidstructure interaction problems, the immersed boundary method, the extended immersed boundary method, the immersed finite element method, and the fictitious domain method. In particular, the key aspects of the immersed continuum method in com...

The term “immersed boundary method” was first used in reference to a method developed by Peskin (1972) to simulate cardiac mechanics and associated blood flow. The distinguishing feature of this method was that the entire simulation was carried out on a Cartesian grid, which did not conform to the geometry of the heart, and a novel procedure was formulated for imposing the effect of the immerse...

The immersed boundary method is a widely used mixed Eulerian/Lagrangian framework for simulating the motion of elastic structures immersed in viscous fluids. In the traditional immersed boundary method, the fluid and structure move with the same velocity field. In this work, a model based on the immersed boundary method is presented for simulating poroelastic media in which the fluid permeates ...

Parachute aerodynamics involves an interaction between the flexible, elastic, porous parachute canopy and the high speed airflow (relative to the parachute) through which the parachute falls. Computer simulation of parachute dynamics typically simplify the problem in various ways, e.g. by considering the parachute as a rigid bluff body. Here, we avoid such simplification by using the immersed b...

We present an immersed boundary method for mass transfer across permeable deformable moving interfaces interacting with the surrounding fluids. One of the key features of our method is the introduction of the mass flux as an independent variable, governed by a non-standard vector transport equation. The flux equation, coupled with the mass transport and the fluid flow equations, allows for a na...

Exploiting a relationship between closed geodesics on a generic closed hyperbolic surface S and a certain unipotent flow on the product space T 1 (S) × T 1 (S), we obtain a local asymptotic equidistribution result for long closed geodesics on S. Applications include asymptotic estimates for the number of pants immersions into S satisfying various geometric constraints. Also we show that two clo...