Numerical simulation of the water bubble rising in a liquid column using the combination of level set and moving mesh methods in the collocated grids

2012 ◽  
Vol 59 ◽  
pp. 1-8 ◽  
Author(s):  
Lin Bu ◽  
Jiyun Zhao
2016 ◽  
Vol 23 (4) ◽  
pp. 1000-1006 ◽  
Author(s):  
Shao-bai Li ◽  
Zheng Yan ◽  
Run-dong Li ◽  
Lei Wang ◽  
Jing-de Luan

2019 ◽  
Vol 14 (2) ◽  
pp. 82-88
Author(s):  
M.V. Alekseev ◽  
I.S. Vozhakov ◽  
S.I. Lezhnin

A numerical simulation of the process of the outflow of gas under pressure into a closed container partially filled with liquid was carried out. For comparative theoretical analysis, an asymptotic model was used with assumptions about the adiabaticity of the gas outflow process and the ideality of the liquid during the oscillatory one-dimensional motion of the liquid column. In this case, the motion of the liquid column and the evolution of pressure in the gas are determined by the equation of dynamics and the balance of enthalpy. Numerical simulation was performed in the OpenFOAM package using the fluid volume method (VOF method) and the standard k-e turbulence model. The evolution of the fields of volumetric gas content, velocity, and pressure during the flow of gas from the high-pressure chamber into a closed channel filled with liquid in the presence of a ”gas blanket“ at the upper end of the channel is obtained. It was shown that the dynamics of pulsations in the gas cavity that occurs when the gas flows into the closed region substantially depends on the physical properties of the liquid in the volume, especially the density. Numerical modeling showed that the injection of gas into water occurs in the form of a jet outflow of gas, and for the outflow into liquid lead, a gas slug is formed at the bottom of the channel. Satisfactory agreement was obtained between the numerical calculation and the calculation according to the asymptotic model for pressure pulsations in a gas projectile in liquid lead. For water, the results of calculations using the asymptotic model give a significant difference from the results of numerical calculations. In all cases, the velocity of the medium obtained by numerical simulation and when using the asymptotic model differ by an order of magnitude or more.


Author(s):  
Patrícia Tonon ◽  
Rodolfo André Kuche Sanches ◽  
Kenji Takizawa ◽  
Tayfun E. Tezduyar

AbstractGood mesh moving methods are always part of what makes moving-mesh methods good in computation of flow problems with moving boundaries and interfaces, including fluid–structure interaction. Moving-mesh methods, such as the space–time (ST) and arbitrary Lagrangian–Eulerian (ALE) methods, enable mesh-resolution control near solid surfaces and thus high-resolution representation of the boundary layers. Mesh moving based on linear elasticity and mesh-Jacobian-based stiffening (MJBS) has been in use with the ST and ALE methods since 1992. In the MJBS, the objective is to stiffen the smaller elements, which are typically placed near solid surfaces, more than the larger ones, and this is accomplished by altering the way we account for the Jacobian of the transformation from the element domain to the physical domain. In computing the mesh motion between time levels $$t_n$$ t n and $$t_{n+1}$$ t n + 1 with the linear-elasticity equations, the most common option is to compute the displacement from the configuration at $$t_n$$ t n . While this option works well for most problems, because the method is path-dependent, it involves cycle-to-cycle accumulated mesh distortion. The back-cycle-based mesh moving (BCBMM) method, introduced recently with two versions, can remedy that. In the BCBMM, there is no cycle-to-cycle accumulated distortion. In this article, for the first time, we present mesh moving test computations with the BCBMM. We also introduce a version we call “half-cycle-based mesh moving” (HCBMM) method, and that is for computations where the boundary or interface motion in the second half of the cycle consists of just reversing the steps in the first half and we want the mesh to behave the same way. We present detailed 2D and 3D test computations with finite element meshes, using as the test case the mesh motion associated with wing pitching. The computations show that all versions of the BCBMM perform well, with no cycle-to-cycle accumulated distortion, and with the HCBMM, as the wing in the second half of the cycle just reverses its motion steps in the first half, the mesh behaves the same way.


2010 ◽  
Vol 3 (S1) ◽  
pp. 635-638 ◽  
Author(s):  
R. Gantois ◽  
A. Cantarel ◽  
G. Dusserre ◽  
J.-N. Félices ◽  
F. Schmidt

2011 ◽  
Vol 317-319 ◽  
pp. 2107-2112
Author(s):  
Song Ying Chen ◽  
Fu Chao Xie ◽  
Jun Jie Mao

Based on two different mixing systems: Rotary Jet Mixing (RJM) system and side-entering agitator, two kinds of three-dimensional gasoline components mixing models are established. The incompressible Reynolds equation is selected as the momentum equation and the algorithm of SIMPLE is used to simulate the jet facility. To get the mixing time, moving mesh and the standard k-ε turbulent model has been employed in the multiphase unsteady flow. The results show that the dead areas of RJM are less than side-entering agitator, and the mixing effects are much better. Furthermore, the mixing time of RJM is only 58.2s, which is 69.7% of Side-entering Agitator.


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