DNS of buoyancy-dominated turbulent flows on a bluff body using the immersed boundary method

2009 ◽  
Vol 228 (9) ◽  
pp. 3189-3208 ◽  
Author(s):  
Seongwon Kang ◽  
Gianluca Iaccarino ◽  
Frank Ham
Keyword(s):  
Turbulent Flows ◽  
Immersed Boundary Method ◽  
Bluff Body ◽  
Immersed Boundary ◽  
Boundary Method

scholarly journals CFD simulation of turbulent flows over wire-wrapped nuclear reactor bundles using immersed boundary method

2020 ◽  
Vol 1599 ◽  
pp. 012022
Author(s):  
Antonio Cervone ◽  
Andrea Chierici ◽  
Leonardo Chirco ◽  
Roberto Da Vià ◽  
Valentina Giovacchini ◽  
...  
Keyword(s):  
Turbulent Flows ◽  
Immersed Boundary Method ◽  
Nuclear Reactor ◽  
Cfd Simulation ◽  
Immersed Boundary ◽  
Boundary Method

Simulation Flows Over Hemisphere at the Bed of an Open Channel by DNS and Immersed Boundary Method

2003 ◽  
Author(s):  
T. X. Dinh
Keyword(s):  
Numerical Simulation ◽  
Turbulent Flows ◽  
Immersed Boundary Method ◽  
Open Channel ◽  
Three Dimensional ◽  
Turbulent Channel Flow ◽  
Time Dependent ◽  
Immersed Boundary ◽  
Boundary Method ◽  
Finite Different Method

The immediate aim of this study is to check the accuracy of Kajishima’s method (one kind of immersed boundary method) for the direct numerical simulation (DNS) of turbulent channel flow over a complicated bed. In this paper, the simulation of three dimensional, time -dependent turbulent flows over a fixed hemisphere at the bed of an open channel is carried out. A finite different method (FDM) is applied with a staggered Cartesian mesh. The forces, the moments about the center of the hemisphere, and the distribution of pressure on the hemisphere in the plane of symmetry are calculated.

Computation of Turbulent Flows in Complex and Moving Geometries Using Immersed Boundary Method

2003 ◽  
Author(s):  
Mayank Tyagi ◽  
Sumanta Acharya
Keyword(s):  
Turbulent Flows ◽  
Immersed Boundary Method ◽  
Complex Geometry ◽  
Fluid Motion ◽  
The Body ◽  
Immersed Boundary ◽  
Full Potential ◽  
Heated Cylinder ◽  
Boundary Method ◽  
Trapped Vortex

A solution methodology for complex turbulent flows of industrial interests is developed using Immersed Boundary Method (IBM). IBM combines the efficiency inherent in using a fixed Cartesian grid to compute the fluid motion, along with the ease of tracking the immersed boundary at a set of moving Lagrangian points. IBM relies upon the body force terms added in the momentum equations to represents the complex geometry on a fixed Cartesian mesh. Resolution issues for turbulent flows can be addressed by Large Eddy Simulation (LES) technique provided an accurate and robust Subgrid Stress (SGS) model is available. Higher order of numerical accuracy schemes for turbulent flows can be maintained as well as the geometrical complexities can be rendered physically by combining LES with IBM. The proposed methodology is simple and ideally suited for the moving geometries involving no-slip walls with prescribed trajectories and locations. IBM is validated for the laminar flow past a heated cylinder in a channel and LES is validated for the turbulent lid-driven cavity flow. LES-IBM is then is used to render complex geometry of trapped vortex combustor to study fluid mixing inside trapped vortex cavity. To demonstrate the full potential of LES-IBM, a complex moving geometry problem of stator-rotor interaction is solved.

Influence of Rounded Corners on Flow Interference Due to Square Cylinders Using Immersed Boundary Method

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
M. B. Shyam Kumar ◽  
S. Vengadesan
Keyword(s):  
Immersed Boundary Method ◽  
Bluff Body ◽  
Immersed Boundary ◽  
Drag Coefficients ◽  
Square Cylinders ◽  
Flow Past ◽  
Corner Radius ◽  
Boundary Method ◽  
Lift And Drag ◽  
Flow Interference

The influence of rounded corners on the aerodynamic forces and flow interference has been studied in detail for a uniform flow past two side-by-side arranged square cylinders. The Reynolds number (Re) based on the cylinder diameter (D) and free stream velocity (U∞) is 100. Numerical simulations are carried out for seven different transverse gap ratios (T/D), each with a minimum and maximum corner radius. An inbuilt finite difference code with staggered arrangement of flow variables is used to discretize the governing equations. The concept of immersed boundary method (IBM) is employed to simulate flow around rounded corners using the regular Cartesian grids. The computational code was validated for flow past an isolated circular cylinder, square cylinder, and two equal sized circular cylinders and the results were found to be in very good agreement with available literatures. In the present study, results in terms of the mean and rms values of lift and drag coefficients, Strouhal number, phase diagrams, and contours of streamlines and vorticity are presented. As the corner radius is increased, a reduction in the drag force is observed. There exists a significant effect of gap ratio and corner radius on the phase angle of lift and drag coefficients. Three different flow patterns, namely the single bluff body flow, biased gapside flow, and two independent bluff body flows, were observed from this study.

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.

Sign in / Sign up

Export Citation Format

Share Document