scholarly journals Direct Numerical Simulation of Gas–Particle Flows with Particle–Wall Collisions Using the Immersed Boundary Method

2018 ◽  
Vol 8 (12) ◽  
pp. 2387 ◽  
Author(s):  
Yusuke Mizuno ◽  
Shun Takahashi ◽  
Kota Fukuda ◽  
Shigeru Obayashi

We investigated particulate flows by coupling simulations of the three-dimensional incompressible Navier–Stokes equation with the immersed boundary method (IBM). The results obtained from the two-way coupled simulation were compared with those of the one-way simulation, which is generally applied for clarifying the particle kinematics in industry. In the present flow simulation, the IBM was solved using a ghost–cell approach and the particles and walls were defined by a level set function. Using proposed algorithms, particle–particle and particle–wall collisions were implemented simply; the subsequent coupling simulations were conducted stably. Additionally, the wake structures of the moving, colliding and rebounding particles were comprehensively compared with previous numerical and experimental results. In simulations of 50, 100, 200 and 500 particles, particle–wall collisions were more frequent in the one–way scheme than in the two-way scheme. This difference was linked to differences in losses in energy and momentum.

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Yusuke Mizuno ◽  
Shun Takahashi ◽  
Taku Nonomura ◽  
Takayuki Nagata ◽  
Kota Fukuda

This study is devoted to investigating a flow around a stationary or moving sphere by using direct numerical simulation with immersed boundary method (IBM) for the three-dimensional compressible Navier-Stokes equations. A hybrid scheme developed to solve both shocks and turbulent flows is employed to solve the flow around a sphere in the equally spaced Cartesian mesh. Drag coefficients of the spheres are compared with reliable values obtained from highly accurate boundary-fitted coordinate (BFC) flow solver to clarify the applicability of the present method. As a result, good agreement was obtained between the present results and those from the BFC flow solver. Moreover, the effectiveness of the hybrid scheme was demonstrated to capture the wake structure of a sphere. Both advantages and disadvantages of the simple IBM were investigated in detail.


Author(s):  
Takeo Kajishima

To deal with a number of solid bodies moving in fluid flow, we proposed an immersed-boundary method, in which the fortified Navier-Stokes equation was applied (Kajishima, et al., 2001). The fluid forces on the bodies are obtained by resolving flow around them. In this paper, some improvement for wider variety of flow conditions is introduced. Then a result of direct numerical simulation (DNS) of turbulence caused by over 1024 particles falling by gravity is demonstrated with particular interest on the influence of particle rotation.


2021 ◽  
Vol 233 ◽  
pp. 109189
Author(s):  
Bin Yan ◽  
Wei Bai ◽  
Sheng-Chao Jiang ◽  
Peiwen Cong ◽  
Dezhi Ning ◽  
...  

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Zhenglun Alan Wei ◽  
Zhongquan Charlie Zheng ◽  
Xiaofan Yang

A parallel implementation of an immersed-boundary (IB) method is presented for low Reynolds number flow simulations in a representative elementary volume (REV) of porous media that are composed of a periodic array of regularly arranged structures. The material of the structure in the REV can be solid (impermeable) or microporous (permeable). Flows both outside and inside the microporous media are computed simultaneously by using an IB method to solve a combination of the Navier–Stokes equation (outside the microporous medium) and the Zwikker–Kosten equation (inside the microporous medium). The numerical simulation is firstly validated using flow through the REVs of impermeable structures, including square rods, circular rods, cubes, and spheres. The resultant pressure gradient over the REVs is compared with analytical solutions of the Ergun equation or Darcy–Forchheimer law. The good agreements demonstrate the validity of the numerical method to simulate the macroscopic flow behavior in porous media. In addition, with the assistance of a scientific parallel computational library, PETSc, good parallel performances are achieved. Finally, the IB method is extended to simulate species transport by coupling with the REV flow simulation. The species sorption behaviors in an REV with impermeable/solid and permeable/microporous materials are then studied.


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