Particle approximation of the two-fluid model for superfluid 4He using smoothed particle hydrodynamics

Poiseuille flows at two Reynolds numbers (Re) 2.5 × 10−2 and 5.0 are simulated by two different smoothed particle hydrodynamics (SPH) schemes on regular and irregular initial particles' distributions. In the first scheme, the viscous stress is calculated directly by the basic SPH particle approximation, while in the second scheme, the viscous stress is calculated by the combination of SPH particle approximation and finite difference method (FDM). The main aims of this paper are (a) investigating the influences of two different schemes on simulations and reducing the numerical instability in simulating Poiseuille flows discovered by other researchers and (b) investigating whether the similar instability exists in other cases and comparing results with the two viscous stress approximations. For Re = 2.5 × 10−2, the simulation with the first scheme becomes instable after the flow approaches to steady-state. However, this instability could be reduced by the second scheme. For Re = 5.0, no instability for two schemes is found.

Download Full-text

Development of smoothed particle hydrodynamics (SPH) method to model the interaction of sand and water during liquefaction with bingham fluid model adaptation

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/622/1/012009 ◽

2021 ◽

Vol 622 ◽

pp. 012009

Author(s):

H Mahardima ◽

E Bahsan ◽

R R D R Marthanty

Keyword(s):

Smoothed Particle Hydrodynamics ◽

Fluid Model ◽

Bingham Fluid ◽

Model Adaptation ◽

Sph Method ◽

Particle Hydrodynamics ◽

Smoothed Particle

Download Full-text

Modeling Large Deformation Slope Failure Using The Smoothed Particle Hydrodynamics (SPH) Method

10.5194/egusphere-egu21-8579 ◽

2021 ◽

Author(s):

Bunyamin Andreatama ◽

Widjojo Adi Prakoso ◽

Erly Bahsan ◽

R.R. Dwinanti Rika Marthanty ◽

Jessica Sjah

Keyword(s):

Slope Stability ◽

Smoothed Particle Hydrodynamics ◽

Slope Failure ◽

Reduction Method ◽

Fluid Model ◽

Bingham Fluid ◽

Strength Reduction Method ◽

Sph Method ◽

Particle Hydrodynamics ◽

Smoothed Particle

<p>The slope stability analyses using limit equilibrium method (LEM) and finite element method (FEM) are mostly concerned about the factor of safety (FS) value of the slope. LEM cannot predict the soil behaviour after failure, while FEM can only be used to measure the material deformation before failure. Currently the Smoothed Particle Hydrodynamics (SPH) method has begun to be used as an alternative to overcome excess distortion of the mesh in FEM analysis due to post-failure large deformations in slope stability analysis. In this study, the behaviour of soil materials will be modelled as particles using the SPH method with reference to the previous research. The Bingham fluid model is used as a viscoplastic model of the soil material, and the Drucker-Prager soil constitutive model is used to describe the elastic-plastic behaviour of the soil. This modelling algorithm uses the equivalent viscosity of the Bingham fluid model as the initial stress between particles, and it uses the Drucker-Prager criterion with the associated flow rule to describe particle displacement due to slope failure. The soil particles are modelled as cohesive soil with a slope angle to the horizontal axis so that they can be compared with previous studies. The failure pattern is expected to be able to show areas of particles that are not deformed and particles that have collapsed. The FS value of the slope is obtained by the strength reduction method which seeks a non-convergent solution of each reduction in soil strength parameters.</p><p>Keywords: Smoothed Particle Hydrodynamics (SPH); Slope Stability; Bingham Fluid Model; Drucker-Prager Model; Strength Reduction Method</p>

Download Full-text