Numerical Investigation of porous walls for a Mach 6.0 Boundary Layer using an Immersed Boundary Method

2011 ◽  
Author(s):  
Christoph Hader ◽  
Hermann Fasel
Keyword(s):  
Boundary Layer ◽  
Numerical Investigation ◽  
Immersed Boundary Method ◽  
Immersed Boundary ◽  
Boundary Method ◽  
Porous Walls

A Combined Volume of Fluid and Immersed Boundary Method for Modelling of Two-Phase Flows with High Density Ratio

2021 ◽  
Author(s):  
Qiu Jin ◽  
Dominic Hudson ◽  
W.G. Price
Keyword(s):  
Boundary Layer ◽  
Immersed Boundary Method ◽  
Density Ratio ◽  
Volume Of Fluid ◽  
High Density ◽  
Immersed Boundary ◽  
Two Phase Flows ◽  
Two Phase ◽  
Boundary Method ◽  
High Density Ratio

Abstract A combined volume of fluid and immersed boundary method is developed to simulate two-phase flows with high density ratio. The problems of discontinuity of density and momentum flux are known to be challenging in simulations. In order to overcome the numerical instabilities, an extra velocity field is designed to extend velocity of the heavier phase into the lighter phase and to enforce a new boundary condition near the interface, which is similar to non-slip boundary conditions in Fluid-Structure Interaction (FSI) problems. The interface is captured using a Volume of Fluid (VOF) method, and a new boundary layer is built on the lighter phase side by an immersed boundary method. The designed boundary layer helps to reduce the spurious velocity caused by the imbalance of dynamic pressure gradient and density gradient and to prevent tearing of the interface due to the tangential velocity across the interface. The influence of time step, density ratio, and spatial resolution is studied in detail for two set of cases, steady stratified flow and convection of a high-density droplet, where direct comparison is possible to potential flow analysis (i.e. infinite Reynold's number). An initial study for a droplet splashing on a thin liquid film demonstrates applicability of the new solver to real-life applications. Detailed comparisons should be performed in the future for finite Reynold's number cases to fully demonstrate the improvements in accuracy and stability of high-density ratio two-phase flow simulations offered by the new method.

An Immersed Boundary Method for General Flow Applications

2010 ◽  
Author(s):  
Jack R. Edwards ◽  
Jung-IL Choi ◽  
Santanu Ghosh ◽  
Daniel A. Gieseking ◽  
Jeffrey D. Eischen
Keyword(s):  
Boundary Layer ◽  
Turbulent Flows ◽  
Immersed Boundary Method ◽  
Human Motion ◽  
Immersed Boundary ◽  
Computational Domain ◽  
General Flow ◽  
Boundary Method ◽  
Boundary Layer Interaction ◽  
A Cell

The development of a direct-forcing immersed-boundary method for general flow applications is outlined in this paper. A cell-classification procedure based on a signed distance to the nearest surface is used to separate the computational domain into cells outside the immersed object (‘field cells’), cells outside but adjacent to the immersed object (‘band cells’), and cells within the immersed object (‘interior cells’). Interpolation methods based on laminar / turbulent boundary layer theory are used to prescribe the flow properties within the ‘band cells’. The method utilizes a decomposition of the velocity field near embedded surfaces into normal and tangential components, with the latter handled using power-law interpolations to mimic the energizing effects of turbulent boundary layers. A procedure for directly embedding sequences of stereo-lithography files as immersed objects in the computational is described, as are extensions of the methodology to compressible, turbulent flows. Described applications include human motion, moving aerodynamic surfaces, and shock / boundary layer interaction flow control.

scholarly journals Numerical Investigation on Vortex-Induced Rotations of A Triangular Cylinder Using An Immersed Boundary Method

2019 ◽  
Vol 33 (6) ◽  
pp. 723-733
Author(s):  
Hua-kun Wang ◽  
Yu-hao Yan ◽  
Can-ming Chen ◽  
Chun-ning Ji ◽  
Qiu Zhai
Keyword(s):  
Numerical Investigation ◽  
Immersed Boundary Method ◽  
Immersed Boundary ◽  
Boundary Method
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