scholarly journals A relaxed multi-direct-forcing immersed boundary-cascaded lattice Boltzmann method accelerated on GPU

2020 ◽  
Vol 248 ◽  
pp. 106980 ◽  
Author(s):  
Ya Zhang ◽  
Guang Pan ◽  
Yonghao Zhang ◽  
Sina Haeri
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Immersed Boundary ◽  
Direct Forcing ◽  
Boltzmann Method

Inclusion of Heat Transfer on Settling Behavior of Elliptical Particles: Immersed Boundary-Thermal Lattice Boltzmann Method

2019 ◽  
Author(s):  
Sajjad Karimnejad ◽  
Amin Amiri Delouei ◽  
Mohsen Nazari ◽  
Mohammad Mohsen Shahmardan ◽  
Goodarz Ahmadi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Immersed Boundary ◽  
Complementary Method ◽  
Elliptical Particles ◽  
Direct Forcing ◽  
Boltzmann Method ◽  
Thermal Lattice Boltzmann ◽  
Settling Behavior

Abstract In this study, the hybrid immersed boundary-thermal lattice Boltzmann method was developed and applied to assess the inclusion of heat transfer in flows containing non-circular particles. The direct forcing/heating immersed boundary method was used for determining the hydrodynamic forces and energy exchange. A complementary method was also implemented to treat non-circularity. The accuracy of the computational model and the employed complementary method were properly validated. Two cases for the falling ellipse were considered. A set of comprehensive simulations were performed and the effects of geometry, Grashof number, repulsive force, and heat transfer were analyzed. The findings of this study would be useful for a better understanding of settling non-circular particles in a thermal field.

Particulate Flow Simulation by the Immersed Boundary Lattice Boltzmann Method

2011 ◽  
Author(s):  
Takeshi Seta
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Flow Simulation ◽  
Correction Method ◽  
Body Motion ◽  
Immersed Boundary ◽  
Cylindrical Couette Flow ◽  
Direct Forcing ◽  
Boltzmann Method ◽  
Direct Forcing Method

We demonstrate the applicability of the immersed boundary lattice Boltzmann method (IB-LBM) based on the implicit correction method to the simulation of rigid body motion in a viscous fluid and to the natural convection calculation. We compare the accuracy of the IB-LBM based on the implicit correction method with one of the IB-LBM based on the direct forcing method that eliminates the necessity of the determination of free parameters. In the simulations of the cylindrical Couette flow and of the heat transfer between two concentric cylinders, the implicit correction method indicates the first-order accuracy in the number of Lagrangian points. The accuracy of the IB-LBM based on the direct forcing method is independent of the number of the boundary points. The IB-LBM based on the implicit correction method is more accurate than one based on the direct forcing method.

scholarly journals A numerical study of fish adaption behaviors in complex environments with a deep reinforcement learning and immersed boundary–lattice Boltzmann method

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yi Zhu ◽  
Fang-Bao Tian ◽  
John Young ◽  
James C. Liao ◽  
Joseph C. S. Lai
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Prey Capture ◽  
Numerical Study ◽  
Benchmark Problems ◽  
Immersed Boundary ◽  
Complex Environments ◽  
Fish Model ◽  
Point To Point ◽  
Boltzmann Method

AbstractFish adaption behaviors in complex environments are of great importance in improving the performance of underwater vehicles. This work presents a numerical study of the adaption behaviors of self-propelled fish in complex environments by developing a numerical framework of deep learning and immersed boundary–lattice Boltzmann method (IB–LBM). In this framework, the fish swimming in a viscous incompressible flow is simulated with an IB–LBM which is validated by conducting two benchmark problems including a uniform flow over a stationary cylinder and a self-propelled anguilliform swimming in a quiescent flow. Furthermore, a deep recurrent Q-network (DRQN) is incorporated with the IB–LBM to train the fish model to adapt its motion to optimally achieve a specific task, such as prey capture, rheotaxis and Kármán gaiting. Compared to existing learning models for fish, this work incorporates the fish position, velocity and acceleration into the state space in the DRQN; and it considers the amplitude and frequency action spaces as well as the historical effects. This framework makes use of the high computational efficiency of the IB–LBM which is of crucial importance for the effective coupling with learning algorithms. Applications of the proposed numerical framework in point-to-point swimming in quiescent flow and position holding both in a uniform stream and a Kármán vortex street demonstrate the strategies used to adapt to different situations.

scholarly journals Research on Human Erythrocyte’s Threshold Free Energy for Hemolysis and Damage from Coupling Effect of Shear and Impact Based on Immersed Boundary-Lattice Boltzmann Method

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zhong Yun ◽  
Chuang Xiang ◽  
Liang Wang
Keyword(s):  
Free Energy ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Coupling Effect ◽  
Threshold Value ◽  
Blood Pump ◽  
Immersed Boundary ◽  
Threshold Limit ◽  
Spring Network Model ◽  
Boltzmann Method

Researches on the principle of human red blood cell’s (RBC) injuring and judgment basis play an important role in decreasing the hemolysis in a blood pump. In the current study, the judgment of hemolysis in a blood pump study was through some experiment data and empirical formula. The paper forms a criterion of RBC’s mechanical injury in the aspect of RBC’s free energy. First, the paper introduces the nonlinear spring network model of RBC in the frame of immersed boundary-lattice Boltzmann method (IB-LBM). Then, the shape, free energy, and time needed for erythrocyte to be shorn in different shear flow and impacted in different impact flow are simulated. Combining existing research on RBC’s threshold limit for hemolysis in shear and impact flow with this paper’s, the RBC’s free energy of the threshold limit for hemolysis is found to be 3.46 × 10 − 15  J. The threshold impact velocity of RBC for hemolysis is 8.68 m/s. The threshold value of RBC can be used for judgment of RBC’s damage when the RBC is having a complicated flow of blood pumps such as coupling effect of shear and impact flow. According to the change law of RBC’s free energy in the process of being shorn and impacted, this paper proposed a judging criterion for hemolysis when the RBC is under the coupling effect of shear and impact based on the increased free energy of RBC.

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