An Immersed Boundary Method Based on the Kinematic Relation of the Velocity-Vorticity Formulation

2014 ◽  
Vol 31 (2) ◽  
pp. 171-181 ◽  
Author(s):  
I. Farahbakhsh ◽  
H. Ghassemi ◽  
F. Sabetghadam
Keyword(s):  
Immersed Boundary Method ◽  
Rigid Motion ◽  
Rigid Bodies ◽  
Immersed Boundary ◽  
Test Cases ◽  
Immersed Boundary Methods ◽  
Vorticity Field ◽  
Boundary Method ◽  
New Interpretation ◽  
Boundary Methods

AbstractAn immersed boundary method is proposed for the simulation of the interaction of an incompressible flow with rigid bodies. The method is based on a new interpretation of velocity-vorticity formulation and no longer includes the force term which is an essential issue of common immersed boundary methods. The system is considered in an Eulerian frame and retrieving the vorticity in this formulation enforces continuity at the fluid-solid interface and rigid motion of the solid. The method focuses on the mutual kinematic relations between the velocity and vorticity fields and with retrieving the vorticity field and recalculating the velocities yields the solenoidal velocity field. The method is applied to the two dimensional problems and the results show that the solenoidality is satisfied acceptably. The comparisons with 2D test cases are provided to illustrate the capabilities of the proposed method.

An New Immersed Boundary Method With Level Set Based Geometry Representation and Volume Fraction Based Body Force Calculation

2018 ◽  
Author(s):  
Guangfa Yao
Keyword(s):  
Level Set ◽  
Immersed Boundary Method ◽  
Body Force ◽  
Volume Fraction ◽  
The Body ◽  
Immersed Boundary ◽  
Immersed Boundary Methods ◽  
Boundary Method ◽  
Boundary Methods ◽  
Fluid Solid Interaction

Immersed boundary method has got increasing attention in modeling fluid-solid interaction using computational fluid dynamics due to its robustness and simplicity. It simulates fluid-solid interaction by adding a body force in the momentum equation without a body conforming mesh generation involved. Different immersed boundary methods have been presented and applied to solve fluid flow with immersed solid bodies. The main difference between these immersed boundary methods is how the body force is calculated. In this paper, a new immersed boundary method is proposed. The body force is calculated based on the volume fraction of the solid body immersed in fluid. Compared to the existing and similar methods, the new method develops a mechanism to calculate the body force and thereby more accurately resolve the physics on the solid-fluid interface. The solid body is represented using a level set that facilitates the calculation of the solid volume fraction. The body force derivation is presented and the method is validated against the test cases with existing analytical solutions or well established numerical solutions. A good match was reached.

Benchmark simulations of flow past rigid bodies using an open-source, sharp interface immersed boundary method

2017 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
Clarence W. Rowley ◽  
Alexander J. Smits ◽  
Nicoleta Herzog ◽  
Hrvoje Jasak ◽  
Daniel Brunner ◽  
...  
Keyword(s):  
Open Source ◽  
Immersed Boundary Method ◽  
Rigid Bodies ◽  
Sharp Interface ◽  
Immersed Boundary ◽  
Flow Past ◽  
Boundary Method

scholarly journals An immersed boundary method for rigid bodies

2016 ◽  
Vol 11 (1) ◽  
pp. 79-141 ◽  
Author(s):  
Bakytzhan Kallemov ◽  
Amneet Bhalla ◽  
Boyce Griffith ◽  
Aleksandar Donev
Keyword(s):  
Immersed Boundary Method ◽  
Rigid Bodies ◽  
Immersed Boundary ◽  
Boundary Method

Implementation of Infinite Height Levee in CaFunwave Using an Immersed Boundary Method

2015 ◽  
Author(s):  
Adam M. Oler ◽  
Ning Zhang ◽  
Steven R. Brandt
Keyword(s):  
Immersed Boundary Method ◽  
Large Scale ◽  
Shallow Water Equation ◽  
Immersed Boundary ◽  
Immersed Boundary Methods ◽  
Boundary Method ◽  
Shape Effects ◽  
Infinite Height ◽  
Grid Points ◽  
Complicated Geometries

Numerical simulations of storm-surge-wave actions on coastal highways and levees are very important research topics for coastal Louisiana. In a large scale region hydrodynamic model, highways and levees are often complicated in geometry and much smaller in size compared to the grid size. The immersed boundary method (IBM) allows for those complicated geometries to be modeled in a less expensive way. It can allow very small geometries to be modeled in a large scale simulation, without requiring them to be explicitly on the grid. It can also allow for complicated geometries not collocated on the grid points. CaFunwave is a project that uses the Cactus Framework for modeling a solitary coastal wave impinging on a coastline, and is the wave solver in this research. The IBM allows for a levee with different geometries to be implemented on a simple Cartesian grid in the CaFunwave package. The IBM has not been used previously for this type of application. Implementing an infinite height levee using the IBM in the Cactus CaFunwave code involves introducing IB forcing terms into the standard 2-D depth averaged shallow water equation set. These forcing terms cause the 2-D solitary wave to experience a virtual force at the grid points surrounding the immersed boundary levee. In this paper the levee was implemented and tested using two different immersed boundary methods. The first method was a feedback-force method, which proved to be more effective at modeling the levee than the second method, the direct-forcing method. In this study, the results of the two methods, as well as the shape effects on the flow, are presented and discussed.

Microstructure simulation of early paper forming using immersed boundary methods

TAPPI Journal ◽  
2011 ◽  
Vol 11 (11) ◽  
pp. 23-30 ◽  
Author(s):  
ANDREAS MARK ◽  
ERIK SVENNING ◽  
ROBERT RUNDQVIST ◽  
FREDRIK EDELVIK ◽  
ERIK GLATT ◽  
...  
Keyword(s):  
Early Paper ◽  
Contact Model ◽  
Fiber Suspension ◽  
Beam Equation ◽  
Immersed Boundary ◽  
Paper Machine ◽  
Immersed Boundary Methods ◽  
Element Discretization ◽  
Microstructure Simulation ◽  
Boundary Methods

Paper forming is the first step in the paper machine where a fiber suspension leaves the headbox and flows through a forming fabric. Complex physical phenomena occur as the paper forms, during which fibers, fillers, fines, and chemicals added to the suspension interact. Understanding this process is important for the development of improved paper products because the configuration of the fibers during this step greatly influences the final paper quality. Because the effective paper properties depend on the microstructure of the fiber web, a continuum model is inadequate to explain the process and the properties of each fiber need to be accounted for in simulations. This study describes a new framework for microstructure simulation of early paper forming. The simulation framework includes a Navier-Stokes solver and immersed boundary methods to resolve the flow around the fibers. The fibers were modeled with a finite element discretization of the Euler-Bernoulli beam equation in a co-rotational formulation. The contact model is based on a penalty method and includes friction and elastic and inelastic collisions. We validated the fiber model and the contact model against demanding test cases from the literature, with excellent results. The fluid-structure interaction in the model was examined by simulating an elastic beam oscillating in a cross flow. We also simulated early paper formation to demonstrate the potential of the proposed framework.

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