Abstract. We consider a nonlinear, moving boundary, fluidstructure interaction problem between a time dependent incompressible, viscous fluid flow, and an elastic structure composed of a cylindrical shell supported by a mesh of elastic rods. The fluid flow is modeled by the timedependent Navier Stokes equations in a threedimensional cylindrical domain, while the lateral wall of the cylinder is modeled by the twodimensional linearly elastic Koiter shell equations coupled to a onedimensional system of conservation laws defined on a graph domain, describing a mesh of curved rods. The mesh supported shell allows displacements in all three spatial directions. Twoway coupling basedmore »
Simulation of unsteady blood flows in a patientspecific compliant pulmonary artery with a highly parallel monolithically coupled fluidstructure interaction algorithm
Computational fluid dynamics (CFD) is increasingly used to study blood flows in
patientspecific arteries for understanding certain cardiovascular diseases. The
techniques work quite well for relatively simple problems but need improvements
when the problems become harder when (a) the geometry becomes
complex (eg, a few branches to a full pulmonary artery), (b) the model becomes
more complex (eg, fluidonly to coupled fluidstructure interaction), (c) both
the fluid and wall models become highly nonlinear, and (d) the computer on
which we run the simulation is a supercomputer with tens of thousands of
processor cores. To push the limit of CFD in all four fronts, in this paper, we
develop and study a highly parallel algorithm for solving a monolithically coupled
fluidstructure system for the modeling of the interaction of the blood
flow and the arterial wall. As a case study, we consider a patientspecific, full
size pulmonary artery obtained from computed tomography (CT) images, with
an artificially added layer of wall with a fixed thickness. The fluid is modeled
with a system of incompressible NavierStokes equations, and the wall is modeled by a geometrically nonlinear elasticity equation. As far as we know, this is the first time the unsteady blood flow in a full pulmonary artery is simulated
without assuming a rigid wall. The proposed numerical more »
 Award ID(s):
 1720366
 Publication Date:
 NSFPAR ID:
 10155913
 Journal Name:
 International journal for numerical methods in biomedical engineering
 ISSN:
 20407939
 Sponsoring Org:
 National Science Foundation
More Like this


Simulation of blood flows in the pulmonary artery provides some insight into certain diseases by examining the relationship between some continuum metrics, e.g., the wall shear stress acting on the vascular endothelium, which responds to flowinduced mechanical forces by releasing vasodilators/constrictors. V. Kheyfets, in his previous work, studies numerically a patientspecific pulmonary circulation to show that decreasing wall shear stress is correlated with increasing pulmonary vascular impedance. In this paper, we develop a scalable parallel algorithm based on domain decomposition methods to investigate an unsteady model with patientspecific pulsatile waveforms as the inlet boundary condition.

This study presents the first 3D twoway coupled fluid structure interaction (FSI) simulation of a hybrid anechoic wind tunnel (HAWT) test section with modeling all important effects, such as turbulence, Kevlar wall porosity and deflection, and reveals for the first time the complete 3D flow structure associated with a lifting model placed into a HAWT. The Kevlar deflections are captured using finite element analysis (FEA) with shell elements operated under a membrane condition. Threedimensional RANS CFD simulations are used to resolve the flow field. Aerodynamic experimental results are available and are compared against the FSI results. Quantitatively, the pressure coefficientsmore »

Nonlinear fluid–structure interaction (FSI) problems on unstructured meshes in 3D appear in many applications in science and engineering, such as vibration analysis of aircrafts and patientspecific diagnosis of cardiovascular diseases. In this work, we develop a highly scalable, parallel algorithmic and software framework for FSI problems consisting of a nonlinear fluid system and a nonlinear solid system, that are coupled monolithically.

Abstract Aerosol jet printing (AJP) is a directwrite additive manufacturing technique, which has emerged as a highresolution method for the fabrication of a broad spectrum of electronic devices. Despite the advantages and critical applications of AJP in the printedelectronics industry, AJP process is intrinsically unstable, complex, and prone to unexpected gradual drifts, which adversely affect the morphology and consequently the functional performance of a printed electronic device. Therefore, in situ process monitoring and control in AJP is an inevitable need. In this respect, in addition to experimental characterization of the AJP process, physical models would be required to explain themore »